{"product_id":"millertech-12v-135ah-dual-purpose-lithium-marine-battery","title":"Millertech 12V 135Ah Dual Purpose Lithium Marine Battery","description":"\u003cstyle\u003e\n  .lbs-page{font-size:18px;line-height:1.6;color:#1a1a1a;max-width:900px;margin:0 auto;font-family:-apple-system,BlinkMacSystemFont,\"Segoe UI\",Roboto,Helvetica,Arial,sans-serif;}\n  .lbs-page h2{font-size:1.6em;margin:1.4em 0 .5em;line-height:1.25;}\n  .lbs-page h3{font-size:1.3em;margin:1.3em 0 .5em;}\n  .lbs-page h4{font-size:1.1em;margin:1.1em 0 .4em;}\n  .lbs-page p{margin:0 0 1em;}\n  .lbs-page ul{margin:0 0 1em;padding-left:1.2em;}\n  .lbs-page li{margin:0 0 .5em;}\n  .lbs-sub{font-size:1.15em;color:#444;font-weight:600;margin-bottom:1.2em;}\n  :root{--lbs-accent:#57b947;--lbs-accent-dark:#2e7d32;}\n  .lbs-benefits{list-style:none;padding:0;margin:1em 0;}\n  .lbs-benefits li{padding:10px 0 10px 30px;position:relative;border-bottom:1px solid #eee;}\n  .lbs-benefits li::before{content:\"\";position:absolute;left:0;top:16px;width:12px;height:12px;background:var(--lbs-accent);border-radius:2px;}\n  .lbs-who{background:#f3f8f1;border-left:4px solid var(--lbs-accent);padding:16px 20px;margin:1.2em 0;border-radius:0 6px 6px 0;}\n  .lbs-table{width:100%;border-collapse:collapse;margin:1em 0;font-size:.95em;}\n  .lbs-table th,.lbs-table td{border:1px solid #ddd;padding:10px 12px;text-align:left;vertical-align:top;}\n  .lbs-table th{background:var(--lbs-accent-dark);color:#fff;font-weight:600;}\n  .lbs-table tr:nth-child(even) td{background:#f4f9f2;}\n  .lbs-rig{background:#fafafa;border:1px solid #e6e6e6;border-radius:6px;padding:14px 16px;margin:0 0 12px;}\n  .lbs-rig strong{color:var(--lbs-accent-dark);}\n  .lbs-note{font-size:.9em;color:#666;font-style:italic;}\n  \/* CSS-only FAQ accordion (house .lbs-faq \/ .lbs-a pattern) *\/\n  .lbs-faq{border-bottom:1px solid #e0e0e0;}\n  .lbs-faq input{position:absolute;opacity:0;pointer-events:none;}\n  .lbs-faq label{display:block;cursor:pointer;font-weight:600;padding:16px 34px 16px 0;position:relative;font-size:1.02em;}\n  .lbs-faq label::after{content:\"+\";position:absolute;right:6px;top:14px;font-size:1.4em;color:var(--lbs-accent-dark);line-height:1;}\n  .lbs-faq input:checked ~ label::after{content:\"\\2212\";}\n  .lbs-a{max-height:0;overflow:hidden;transition:max-height .35s ease;}\n  .lbs-faq input:checked ~ .lbs-a{max-height:1200px;}\n  .lbs-a p{padding:0 0 16px;margin:0;}\n  .lbs-faqgroup{margin:1.4em 0;}\n  .lbs-faqgroup \u003e h4{border-bottom:2px solid var(--lbs-accent);padding-bottom:6px;}\n\u003c\/style\u003e\n\u003cdiv class=\"lbs-page\"\u003e\n\u003cp\u003eThe Millertech 12V 135Ah Dual Purpose is a LiFePO4 (lithium iron phosphate) battery built to do two jobs from a single Group 31 box: deliver the high burst of current needed to \u003cstrong\u003estart your outboard\u003c\/strong\u003e, and provide the steady, stable \u003cstrong\u003edeep-cycle energy\u003c\/strong\u003e that today's electronics-heavy boats demand. It carries a 1500 CCA cranking rating and 135Ah of storage, with a Battery Management System (BMS) that handles over-charge, over-discharge, over-current, and temperature protection automatically.\u003c\/p\u003e\n\u003cp\u003eFor most bass, bay, and multi-species anglers, this is the \"one battery\" answer, it cranks the motor and runs the console and bow electronics off the same source, which is why owners routinely report replacing a pair of lead-acid batteries with a single Millertech and shedding weight in the process.\u003c\/p\u003e\n\u003cdiv class=\"lbs-who\"\u003e\n\u003ch4\u003eWho this battery is for\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003eAnglers who want a \u003cstrong\u003esingle starting + electronics battery\u003c\/strong\u003e instead of separate cranking and house batteries.\u003c\/li\u003e\n\u003cli\u003eBoaters running \u003cstrong\u003eforward-facing sonar\u003c\/strong\u003e (LiveScope, Mega Live, ActiveTarget) plus multiple graphs who keep dipping their AGM too low.\u003c\/li\u003e\n\u003cli\u003eAnyone cutting weight, a 33 lb lithium replacing a 50-60 lb AGM Group 31.\u003c\/li\u003e\n\u003cli\u003eRV, off-grid, solar, tiny-home, and golf-cart users who need a rugged 12V dual-purpose battery.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eWho should look elsewhere\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003eIf your engine maker \u003cstrong\u003especifically prohibits\u003c\/strong\u003e lithium starting batteries and you don't want to add a DC-DC charger, a dedicated deep-cycle lithium plus an AGM cranking battery may suit you better. See the Charging \u0026amp; Engine Compatibility tab.\u003c\/li\u003e\n\u003cli\u003eIf you need a dedicated \u003cstrong\u003e24V or 36V trolling motor\u003c\/strong\u003e bank use Millertech's dedicated 24V\/36V trolling batteries for that job (see Trolling Motors below).\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003ch4\u003eStandard vs. Heated, which variant?\u003c\/h4\u003e\n\u003cp\u003eThis page offers two versions. The \u003cstrong\u003eStandard (12135-DP)\u003c\/strong\u003e is the right choice for most boaters, especially in warm climates. The \u003cstrong\u003eHeated (12135-DPH)\u003c\/strong\u003e adds smart self-heating for cold-weather \u003cem\u003echarging\u003c\/em\u003e: when it is connected to a charger and the internal temperature drops to 32°F, the heater automatically warms the battery to 34°F before charging resumes, so freezing temperatures don't stop you from topping off. Note the heater runs \u003cstrong\u003eonly while connected to a charger,\u003c\/strong\u003e it is a cold-charging feature, not a discharge warmer. If you launch, store, or charge in sub-freezing conditions, choose Heated.\u003c\/p\u003e\n\u003c!-- ================= TAB: IS THIS THE RIGHT BATTERY ================= --\u003e\n\u003ch4\u003eIs this the right battery for you?\u003c\/h4\u003e\n\u003cp\u003e\u003cstrong\u003eChoose this battery if you:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eRun a Mercury outboard that permits lithium starting batteries and want \u003cstrong\u003eone battery to crank the motor and run your electronics\u003c\/strong\u003e.\u003c\/li\u003e\n\u003cli\u003eFish with \u003cstrong\u003eforward-facing sonar and multiple graphs\u003c\/strong\u003e and keep pulling your AGM too low by the afternoon.\u003c\/li\u003e\n\u003cli\u003eWant to \u003cstrong\u003ecut weight\u003c\/strong\u003e by replacing one or two lead-acid batteries with a single 33 lb lithium.\u003c\/li\u003e\n\u003cli\u003eFish tournaments or long days and need \u003cstrong\u003estable voltage from launch to weigh-in\u003c\/strong\u003e.\u003c\/li\u003e\n\u003cli\u003eWant \u003cstrong\u003eBluetooth monitoring\u003c\/strong\u003e so you know your charge before you leave the ramp.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eConsider a different setup if you:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eNeed a dedicated \u003cstrong\u003e24V or 36V trolling motor\u003c\/strong\u003e bank use a Millertech 24V\/36V trolling battery for that job.\u003c\/li\u003e\n\u003cli\u003eRun an engine whose maker \u003cstrong\u003eprohibits lithium cranking batteries\u003c\/strong\u003e and you don't want to add a DC-DC charger pair an AGM cranking battery with a lithium house battery instead.\u003c\/li\u003e\n\u003cli\u003eOnly need light, occasional electronics power on a small boat, a smaller-capacity battery may be enough.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003ePopular with:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eTournament bass anglers and weekend fishermen\u003c\/li\u003e\n\u003cli\u003eBay boats, multi-species, walleye, crappie, and musky rigs\u003c\/li\u003e\n\u003cli\u003eElectronics-heavy boats running forward-facing sonar\u003c\/li\u003e\n\u003cli\u003eRV, off-grid, solar, and tiny-home 12V systems\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- ================= TAB 2: WHY UPGRADE FROM AGM ================= --\u003e\n\u003ch4\u003eWhy upgrade from AGM\u003c\/h4\u003e\n\u003cp\u003eSerious anglers move off AGM and flooded lead-acid for a handful of concrete reasons:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eVoltage stays flat.\u003c\/strong\u003e Lead-acid sags as it drains, which is exactly when forward-facing sonar starts dropping out. LiFePO4 holds a stable voltage deep into the discharge, so your graphs stay lit and connected.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMore usable capacity.\u003c\/strong\u003e You can safely use nearly all of a lithium battery's rated capacity, versus roughly half of a lead-acid battery, so 135Ah of lithium does the work of a much larger AGM.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight.\u003c\/strong\u003e At 33 lb, it is a fraction of a comparable lead-acid starting battery, and consolidating two batteries into one compounds the savings.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFaster charging and no memory effect.\u003c\/strong\u003e Charge it at any state of charge without harming capacity.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLong, maintenance-free service life.\u003c\/strong\u003e Millertech rates the Sport Series for many times the cycle life of lead-acid, backed by a 10-year warranty.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- ================= TAB 3: APPLICATIONS ================= --\u003e\n\u003ch3\u003eApplications \u0026amp; Compatibility\u003c\/h3\u003e\n\u003ch4\u003eCommon applications\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBass boats, \u003c\/strong\u003esingle cranking + electronics battery.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBay boats, multi-species, and center-console rigs, \u003c\/strong\u003eas a starting battery, house\/electronics battery, or both.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eForward-facing sonar setups,\u003c\/strong\u003e a dedicated electronics battery for FFS and networked graphs.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRV and campers, \u003c\/strong\u003edual-purpose starting and house power.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOff-grid, solar, and tiny homes,\u003c\/strong\u003e 12V storage with a rugged, sealed case.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGolf carts and utility vehicles,\u003c\/strong\u003e 12V applications needing both cranking and cycling.\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eEmergency and backup power.\u003c\/strong\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- ================= TAB: BOAT, ENGINE \u0026 ELECTRONICS COMPATIBILITY ================= --\u003e\n\u003ch4\u003eBoat, engine \u0026amp; electronics compatibility\u003c\/h4\u003e\n\u003cp\u003e\u003cstrong\u003eBoats it's commonly installed on\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eAs a Group 31 dual-purpose battery, it drops into the standard trays used across most fishing platforms, Skeeter, Ranger, Phoenix, Bass Cat, Nitro, Triton, Caymas, Vexus, Blazer, Falcon, Xpress, SeaArk, Lund, Alumacraft, Crestliner, and Tracker among them. If you're searching for a battery for a specific hull (for example, a Ranger Z520 or a Phoenix 921), the fit comes down to your Group 31 tray and your engine's charging requirements, confirm both before ordering.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eEngines\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eMillertech states this battery meets the cranking and charging requirements for \u003cstrong\u003eMercury 4-stroke outboards up to 250 hp\u003c\/strong\u003e (Pro XS, FourStroke, and Verado families), consistent with Mercury's service bulletin permitting lithium starting batteries on qualifying engines. Owners have run them since 2016.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eFor other brands: Yamaha (SHO, VMAX), Suzuki, Honda, Tohatsu verify with the engine manufacturer first.\u003c\/strong\u003e Several have not approved lithium cranking batteries, or require specific conditions. When in doubt, run a dedicated AGM cranking battery alongside a lithium house battery with a DC-DC charger. Always confirm against your engine's current manual before converting.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eElectronics it powers\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThis battery supplies stable 12V power to essentially any marine electronics you can wire to it. Because LiFePO4 holds a flat voltage deep into the discharge, voltage-sensitive gear stays lit and connected far longer than on a sagging lead-acid battery. Commonly powered gear includes:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eForward-facing sonar (FFS):\u003c\/strong\u003e Garmin LiveScope (LVS34, LVS62), Humminbird MEGA Live and MEGA Live 2, Lowrance ActiveTarget and ActiveTarget 2.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eChartplotters and graphs:\u003c\/strong\u003e Garmin, Humminbird, and Lowrance multifunction displays, including networked NMEA 2000 setups.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTrolling motors (as a house\/electronics source, not the trolling bank):\u003c\/strong\u003e Minn Kota Ultrex, Quest, and Ghost; Garmin Force and Force Pro; MotorGuide Tour Pro; Rhodan.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAccessories:\u003c\/strong\u003e Power-Pole shallow-water anchors, livewell and bilge pumps, aerators, lighting, stereo, and USB charging.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"lbs-note\"\u003eElectronics are electrical loads, not compatibility restrictions any 12V device can be powered. Naming a brand here does not imply endorsement by that manufacturer.\u003c\/p\u003e\n\u003c!-- ================= TAB 4: REAL RIGS \/ IN THE FIELD ================= --\u003e\n\u003ch3\u003eReal-World Performance\u003c\/h3\u003e\n\u003cp\u003eBoaters have shared the setups they power from a single 12V 135Ah Dual Purpose. Individual results vary with your loads, run time, and how you fish, but these give a realistic picture of what one battery handles:\u003c\/p\u003e\n\u003ch4\u003eEstimated runtime by setup\u003c\/h4\u003e\n\u003ctable class=\"lbs-table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eTypical setup\u003c\/th\u003e\n\u003cth\u003eApprox. draw\u003c\/th\u003e\n\u003cth\u003eEstimated runtime\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeekend: two 12″ graphs + one forward-facing sonar\u003c\/td\u003e\n\u003ctd\u003e~7-8A\u003c\/td\u003e\n\u003ctd\u003e~15-18 hours\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTournament: three graphs + FFS with turret + intermittent livewell\u003c\/td\u003e\n\u003ctd\u003e~12-14A\u003c\/td\u003e\n\u003ctd\u003e~9-11 hours\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eHeavy: four graphs + two FFS modules + steady aerators\u003c\/td\u003e\n\u003ctd\u003e~16-18A\u003c\/td\u003e\n\u003ctd\u003e~7-8 hours\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp class=\"lbs-note\"\u003eEstimates only, based on typical 2-3A draw per graph or forward-facing sonar module and 135Ah of capacity; engine cranking draw is negligible over a day. Real results vary with your exact electronics, backlight level, and pump duty cycle. Putting units in standby during runs extends runtime.\u003c\/p\u003e\n\u003cdiv class=\"lbs-rig\"\u003e\n\u003cstrong\u003eWhole-boat single battery.\u003c\/strong\u003e One angler runs a 10-, 12-, and 16-inch graph plus a forward-facing sonar unit with turret, Power-Pole shallow-water anchors, two oxygenators, and a livewell air pump off one Dual Purpose and reports staying above 90% even on tournament days, paired with a separate 36V trolling battery.\u003c\/div\u003e\n\u003cdiv class=\"lbs-rig\"\u003e\n\u003cstrong\u003eTwin Humminbird + Mega Live.\u003c\/strong\u003e Two Humminbird units and Mega Live 2 ran all day without dipping below 12.6V; back at the ramp the battery still read about 95%.\u003c\/div\u003e\n\u003cdiv class=\"lbs-rig\"\u003e\n\u003cstrong\u003eTwin Lowrance HDS-12 Live.\u003c\/strong\u003e A full day on two HDS-12 Live screens, with the battery health checked at 99% at day's end.\u003c\/div\u003e\n\u003cdiv class=\"lbs-rig\"\u003e\n\u003cstrong\u003eFull electronics load plus starting.\u003c\/strong\u003e Two Lowrance 12-inch units, two Power-Pole blades, ActiveTarget, and livewell pumps, plus cranking a 150 Mercury roughly 50% remaining after an eight-hour tournament.\u003c\/div\u003e\n\u003cdiv class=\"lbs-rig\"\u003e\n\u003cstrong\u003eWeight-saving consolidation.\u003c\/strong\u003e Moving to a single starting\/electronics battery that also works with a Mercury alternator trimmed close to 125 lb off the boat.\u003c\/div\u003e\n\u003cdiv class=\"lbs-rig\"\u003e\n\u003cstrong\u003e24V trolling from a pair.\u003c\/strong\u003e Some owners run two 135Ah Dual Purpose batteries to drive a 24V Minn Kota. If you plan a series bank, read the Trolling Motors note below first.\u003c\/div\u003e\n\u003c!-- ================= TAB 5: CHARGING \u0026 ENGINE COMPATIBILITY ================= --\u003e\n\u003ch3\u003eCharging \u0026amp; Installation\u003c\/h3\u003e\n\u003ch4\u003eWhat charger should I use?\u003c\/h4\u003e\n\u003cp\u003eUse a lithium (LiFePO4) charger. This battery is built around a 14.6V max charge voltage, and a lead-acid or AGM charger set to higher absorption or equalization voltages can trip the BMS or stress the cells. Equalization is not recommended turn it off if your charger has it. Millertech's recommended charge current is about 30A, and the battery accepts up to 135A maximum. Matching chargers below.\u003c\/p\u003e\n\u003ctable class=\"lbs-table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eCharger\u003c\/th\u003e\n\u003cth\u003eBest for\u003c\/th\u003e\n\u003cth\u003eNotes\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e12V 10A (1210C)\u003c\/td\u003e\n\u003ctd\u003eOvernight \/ light use\u003c\/td\u003e\n\u003ctd\u003e110V AC plug-in, most economical\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e12V 20A (1220C)\u003c\/td\u003e\n\u003ctd\u003eSame-day recharge\u003c\/td\u003e\n\u003ctd\u003e110V AC plug-in, roughly twice as fast\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e12V 20A On-Board (1220M)\u003c\/td\u003e\n\u003ctd\u003ePermanent boat install\u003c\/td\u003e\n\u003ctd\u003eIP65 waterproof, plug into shore power\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e12V-24V Dark Speed On-The-Run\u003c\/td\u003e\n\u003ctd\u003e12V + 24V systems\u003c\/td\u003e\n\u003ctd\u003eCharges while you run; IP65\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e12V-36V Dark Speed On-The-Run\u003c\/td\u003e\n\u003ctd\u003e12V + 36V systems\u003c\/td\u003e\n\u003ctd\u003eCharges while you run; IP65\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e2-Bank \/ 3-Bank On-Board (1215-2, 1215-3, 121624-3, 121636-3)\u003c\/td\u003e\n\u003ctd\u003eMultiple batteries at once\u003c\/td\u003e\n\u003ctd\u003eIsolated banks; charge start + electronics + trolling together\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch4\u003eCan I use a NOCO or my existing onboard marine charger?\u003c\/h4\u003e\n\u003cp\u003eYes, provided it has a true lithium\/LiFePO4 mode. Many marine chargers (including NOCO Genius models) offer a selectable lithium profile. Avoid charging on a lead-acid-only profile with high equalization voltage.\u003c\/p\u003e\n\u003ch4\u003eCan I charge it from my outboard's alternator while running?\u003c\/h4\u003e\n\u003cp\u003eThis is the most important compatibility question for a lithium starting battery, so here is the straight answer. Because lithium has low internal resistance, it can pull a high charge current, and a marine alternator running at full output for long stretches generates heat. Millertech states this battery meets the cranking and charging requirements to work with \u003cstrong\u003eMercury 4-stroke outboards up to 250 hp\u003c\/strong\u003e, and reports customers running them since 2016. Mercury has issued a service bulletin permitting lithium starting batteries on qualifying engines when the battery meets their specifications.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eAlways confirm against your own engine's manual or service bulletin before installing.\u003c\/strong\u003e Yamaha, Suzuki, and Honda have generally not approved lithium starting batteries at the time of writing; if you run one of these engines, verify with the engine manufacturer first, or run a dedicated AGM cranking battery with a lithium house battery and a DC-DC charger.\u003c\/p\u003e\n\u003ch4\u003eStorage and winterizing\u003c\/h4\u003e\n\u003cp\u003eLiFePO4 stores well. Charge it, disconnect it, and keep it in a cool, dry place; it does not need a constant trickle charge. Self-discharge is under 4% per month.\u003c\/p\u003e\n\u003c!-- ================= TAB 6: COLD WEATHER \u0026 HEATED ================= --\u003e\n\u003ch4\u003eCold weather \u0026amp; low-temp protection\u003c\/h4\u003e\n\u003cp\u003eEvery version of this battery includes built-in low-temperature charging protection. The recommended charge temperature range is 25°F-131°F, and the BMS blocks charging when the battery is too cold to prevent the permanent damage (lithium plating) that occurs if a LiFePO4 cell is charged below freezing. The battery still delivers power in cold conditions, but its rated operating range is 32°F-130°F and usable capacity drops as temperatures fall; the low-temp protection specifically prevents \u003cem\u003echarging\u003c\/em\u003e below freezing.\u003c\/p\u003e\n\u003cp\u003eThe \u003cstrong\u003eHeated (12135-DPH)\u003c\/strong\u003e version adds a smart heater for cold-weather charging: connected to a charger, if internal temperature drops to 32°F the heater warms the battery to 34°F, then charging resumes automatically. The heater runs only while a charger is connected. If you fish, store, or charge in freezing conditions, the Heated variant removes the guesswork.\u003c\/p\u003e\n\u003c!-- ================= TAB 7: TROLLING MOTORS ================= --\u003e\n\u003ch4\u003eTrolling motors (24V \/ 36V)\u003c\/h4\u003e\n\u003cp\u003eThis battery is designed as a 12V cranking and house battery. For a \u003cstrong\u003e24V or 36V trolling motor\u003c\/strong\u003e, the cleanest setup is a dedicated Millertech 24V or 36V trolling battery sized to your motor, kept separate from the starting battery. That is how most owners run it: one Dual Purpose for the boat, a separate higher-voltage battery for the trolling motor.\u003c\/p\u003e\n\u003cp\u003eSome anglers do wire two 12V 135Ah Dual Purpose batteries in series to build a 24V bank. If that is your plan, \u003cstrong\u003econfirm the exact series\/parallel configuration and limits with Millertech before wiring\u003c\/strong\u003e, and always use identical batteries (same model, capacity, and age) with proper fusing. Contact us and we'll confirm the right configuration for your motor.\u003c\/p\u003e\n\u003c!-- ================= TAB 8: INSTALLATION ================= --\u003e\n\u003ch4\u003eInstallation\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eFitment.\u003c\/strong\u003e This is a true BCI Group 31 (13″ x 6.75″ x 9″) and drops into standard Group 31 trays. A matching tray is available if you need one.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTerminals.\u003c\/strong\u003e Heavy-duty M8 bolts and washers in 18-8 stainless. Torque terminal connections to 10 ft-lbs. If you are stacking multiple lugs, you may need to remove a washer or use a slightly longer bolt to fully seat into the copper pillar.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOrientation and mounting.\u003c\/strong\u003e Seat the battery in the tray and secure with hold-down straps; the case has molded strap grooves to keep straps in place.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWiring.\u003c\/strong\u003e Use correctly sized cables and fuse\/breaker protection appropriate to your loads. Connect electronics and accessories to the battery through a fused distribution point.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eApp.\u003c\/strong\u003e Download the Millertech Bluetooth app to monitor charge percentage, voltage, current, and temperature.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- ================= TAB 9: SPECIFICATIONS ================= --\u003e\n\u003ch3\u003eSpecifications\u003c\/h3\u003e\n\u003ctable class=\"lbs-table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003cth\u003eStandard (12135-DP)\u003c\/th\u003e\n\u003cth\u003eHeated (12135-DPH)\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCapacity\u003c\/td\u003e\n\u003ctd\u003e135Ah\u003c\/td\u003e\n\u003ctd\u003e135Ah\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eEnergy storage\u003c\/td\u003e\n\u003ctd\u003e1.728 kWh\u003c\/td\u003e\n\u003ctd\u003e1.728 kWh\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNominal voltage\u003c\/td\u003e\n\u003ctd\u003e12.8V\u003c\/td\u003e\n\u003ctd\u003e12.8V\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eChemistry \/ cell type\u003c\/td\u003e\n\u003ctd\u003eLiFePO4 \/ prismatic\u003c\/td\u003e\n\u003ctd\u003eLiFePO4 \/ prismatic\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCold Cranking Amps (CCA)\u003c\/td\u003e\n\u003ctd\u003e1500A\u003c\/td\u003e\n\u003ctd\u003e1500A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePeak discharge (up to 5 sec)\u003c\/td\u003e\n\u003ctd\u003e300A\u003c\/td\u003e\n\u003ctd\u003e300A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMax continuous charge \/ discharge\u003c\/td\u003e\n\u003ctd\u003e135A\u003c\/td\u003e\n\u003ctd\u003e135A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRecommended charge current\u003c\/td\u003e\n\u003ctd\u003e30A\u003c\/td\u003e\n\u003ctd\u003e30A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMax charge voltage\u003c\/td\u003e\n\u003ctd\u003e14.6V\u003c\/td\u003e\n\u003ctd\u003e14.6V\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFloat voltage\u003c\/td\u003e\n\u003ctd\u003e13.5V\u003c\/td\u003e\n\u003ctd\u003e13.5V\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLow-voltage cutoff\u003c\/td\u003e\n\u003ctd\u003e10.5V\u003c\/td\u003e\n\u003ctd\u003e10.5V\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRecommended low-voltage disconnect\u003c\/td\u003e\n\u003ctd\u003e12.0V\u003c\/td\u003e\n\u003ctd\u003e12.0V\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCharge temp range (low-temp protection)\u003c\/td\u003e\n\u003ctd\u003e25°F to 131°F\u003c\/td\u003e\n\u003ctd\u003e25°F to 131°F\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSelf-heating\u003c\/td\u003e\n\u003ctd\u003eNo\u003c\/td\u003e\n\u003ctd\u003eYes (32°F trigger on charger, warms to 34°F)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDischarge \/ operating temp range\u003c\/td\u003e\n\u003ctd\u003e32°F to 130°F\u003c\/td\u003e\n\u003ctd\u003e32°F to 130°F\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eEfficiency\u003c\/td\u003e\n\u003ctd\u003e98%\u003c\/td\u003e\n\u003ctd\u003e98%\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSelf-discharge\u003c\/td\u003e\n\u003ctd\u003e\u0026lt; 4% \/ month\u003c\/td\u003e\n\u003ctd\u003e\u0026lt; 4% \/ month\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMemory effect\u003c\/td\u003e\n\u003ctd\u003eNone\u003c\/td\u003e\n\u003ctd\u003eNone\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBMS\u003c\/td\u003e\n\u003ctd\u003eYes\u003c\/td\u003e\n\u003ctd\u003eYes\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBluetooth\u003c\/td\u003e\n\u003ctd\u003eYes\u003c\/td\u003e\n\u003ctd\u003eYes\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTerminals\u003c\/td\u003e\n\u003ctd\u003eM8 18-8 stainless, 10 ft-lbs\u003c\/td\u003e\n\u003ctd\u003eM8 18-8 stainless, 10 ft-lbs\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCase\u003c\/td\u003e\n\u003ctd\u003eSealed IP65, rubber gasket, stainless breather vent\u003c\/td\u003e\n\u003ctd\u003eSealed IP65, rubber gasket, stainless breather vent\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eGroup size\u003c\/td\u003e\n\u003ctd\u003eBCI Group 31\u003c\/td\u003e\n\u003ctd\u003eBCI Group 31\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions\u003c\/td\u003e\n\u003ctd\u003e13″ x 6.75″ x 9″\u003c\/td\u003e\n\u003ctd\u003e13″ x 6.75″ x 9″\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e33 lbs\u003c\/td\u003e\n\u003ctd\u003e33 lbs\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWarranty\u003c\/td\u003e\n\u003ctd\u003e10 years\u003c\/td\u003e\n\u003ctd\u003e10 years\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp class=\"lbs-note\"\u003eSpecifications per Millertech published data sheets. Confirm against the current manufacturer manual for your exact SKU.\u003c\/p\u003e\n\u003c!-- ================= TAB 10: AGM VS MILLERTECH ================= --\u003e\n\u003ch4\u003eAGM vs. Millertech lithium\u003c\/h4\u003e\n\u003ctable class=\"lbs-table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003e \u003c\/th\u003e\n\u003cth\u003eTypical AGM Group 31\u003c\/th\u003e\n\u003cth\u003eMillertech 135Ah Dual Purpose\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eUsable capacity\u003c\/td\u003e\n\u003ctd\u003e~50% of rated\u003c\/td\u003e\n\u003ctd\u003eNearly all of rated\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eVoltage under load\u003c\/td\u003e\n\u003ctd\u003eSags as it drains\u003c\/td\u003e\n\u003ctd\u003eStays flat deep into discharge\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e~50-60 lb\u003c\/td\u003e\n\u003ctd\u003e33 lb\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCharge speed\u003c\/td\u003e\n\u003ctd\u003eSlower\u003c\/td\u003e\n\u003ctd\u003eFast, no memory effect\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaintenance\u003c\/td\u003e\n\u003ctd\u003ePeriodic\u003c\/td\u003e\n\u003ctd\u003eNone\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMonitoring\u003c\/td\u003e\n\u003ctd\u003eExternal meter\u003c\/td\u003e\n\u003ctd\u003eBuilt-in Bluetooth app\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWarranty\u003c\/td\u003e\n\u003ctd\u003eTypically 1-4 years\u003c\/td\u003e\n\u003ctd\u003e10 years\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c!-- ================= TAB: FAQ ================= --\u003e\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cdiv class=\"lbs-faqgroup\"\u003e\n\u003ch4\u003eStarting \u0026amp; cranking\u003c\/h4\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q1\"\u003e\u003clabel for=\"q1\"\u003eCan this battery start my outboard?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eYes. It is rated at 1500 CCA with a 300A peak discharge, which delivers the burst of current outboards need to crank, while retaining 135Ah of reserve for your electronics.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q2\"\u003e\u003clabel for=\"q2\"\u003eWill it start a Mercury 250 Pro XS?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eMillertech states the battery meets the cranking and charging requirements to work with Mercury 4-stroke outboards up to 250 hp, and reports customers using them since 2016. Confirm against your engine's manual and Mercury's lithium service bulletin.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q3\"\u003e\u003clabel for=\"q3\"\u003eCan I use it to start and run electronics from the same battery?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eYes, that is the \"dual purpose\" design. It provides high cranking current plus deep-cycle capacity, so one battery can crank the motor and power your graphs, pumps, and accessories.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q4\"\u003e\u003clabel for=\"q4\"\u003eWill it crank a big V8 outboard reliably all day?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eOwners report cranking 150-250 hp outboards repeatedly through a full tournament day while also running electronics. Your reserve at day's end depends on your total electronics load.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q5\"\u003e\u003clabel for=\"q5\"\u003eIs it a Group 31 replacement?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eYes. It is a true BCI Group 31 (13″ x 6.75″ x 9″) and fits standard Group 31 trays.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q43\"\u003e\u003clabel for=\"q43\"\u003eWill it start a Yamaha SHO, Suzuki, or Honda outboard?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eIt has the cranking power to turn these engines over, but Yamaha, Suzuki, and Honda have generally not approved lithium starting batteries, or set specific conditions. Confirm with your engine manufacturer before converting; if in doubt, run an AGM cranking battery with a lithium house battery and a DC-DC charger.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"lbs-faqgroup\"\u003e\n\u003ch4\u003eCharging\u003c\/h4\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q6\"\u003e\u003clabel for=\"q6\"\u003eWhat charger should I use?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eUse a lithium\/LiFePO4 charger built for a 14.6V profile. Millertech's recommended charge current is about 30A. See the charger table above for matching options.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q7\"\u003e\u003clabel for=\"q7\"\u003eCan I use my existing lead-acid or AGM charger?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eOnly if it has a true lithium mode. Lead-acid profiles with high absorption or equalization voltages can trip the BMS or stress the cells. Turn off equalization.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q8\"\u003e\u003clabel for=\"q8\"\u003eCan I use a NOCO Genius?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eYes, in its lithium mode. NOCO Genius models offer a selectable LiFePO4 profile suitable for this battery.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q9\"\u003e\u003clabel for=\"q9\"\u003eCan I charge it from my outboard alternator?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eOn Mercury engines that permit lithium starting batteries per their bulletin, yes. Because lithium draws high charge current, verify your specific engine is approved and consider a DC-DC charger where required. See the Charging \u0026amp; Engine Compatibility tab.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q10\"\u003e\u003clabel for=\"q10\"\u003eCan I use an on-the-run charger?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eYes. The Dark Speed 12V-24V and 12V-36V on-the-run chargers top the battery off while you operate, using excess energy from your charging system.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q11\"\u003e\u003clabel for=\"q11\"\u003eHow fast does it charge?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eCharge time depends on the charger. A 20A charger recharges faster than a 10A; the battery accepts up to 135A but 30A is the recommended current for battery health.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q12\"\u003e\u003clabel for=\"q12\"\u003eCan I leave it on a maintainer?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eLiFePO4 does not need a constant trickle. Use a charger with a proper lithium maintenance stage, or simply charge and disconnect for storage.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q13\"\u003e\u003clabel for=\"q13\"\u003eWhat voltage should I charge to?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eMax charge voltage is 14.6V, with a 13.5V float. Do not use equalization.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"lbs-faqgroup\"\u003e\n\u003ch4\u003eElectronics \u0026amp; runtime\u003c\/h4\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q14\"\u003e\u003clabel for=\"q14\"\u003eCan it run LiveScope, Mega Live, or ActiveTarget?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eYes. It powers forward-facing sonar and networked graphs with stable voltage. Owners run FFS plus multiple large screens off a single battery.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q15\"\u003e\u003clabel for=\"q15\"\u003eHow long will it run my electronics?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eA useful planning figure many anglers use is roughly 2Ah per graph or FFS module per hour. With 135Ah, that supports several units through a long day. Livewell aerators add significant draw, so account for them.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q16\"\u003e\u003clabel for=\"q16\"\u003eCan it power multiple graphs at once?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eYes. Owners report running three or four large graphs plus FFS with reserve to spare after a full day.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q17\"\u003e\u003clabel for=\"q17\"\u003eCan it power shallow-water anchors like Power-Pole?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eYes. It powers Power-Pole and similar 12V accessories alongside your electronics.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q18\"\u003e\u003clabel for=\"q18\"\u003eCan it run livewell and bilge pumps?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eYes. Pumps and aerators are among the heavier loads on the boat; the 135Ah capacity is sized to handle them along with electronics.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q19\"\u003e\u003clabel for=\"q19\"\u003eWhy does my sonar drop out with lead-acid but not lithium?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eLead-acid voltage sags as it drains, and sonar can disconnect at low voltage. LiFePO4 holds a flat voltage deep into the discharge, keeping screens lit and connected.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q20\"\u003e\u003clabel for=\"q20\"\u003eShould I put my electronics on a separate battery?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eMany anglers run everything off one Dual Purpose. If you run an unusually heavy electronics load or fish very long days, a dedicated electronics battery adds margin.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"lbs-faqgroup\"\u003e\n\u003ch4\u003eCold weather\u003c\/h4\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q21\"\u003e\u003clabel for=\"q21\"\u003eCan I use it in freezing weather?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eIt still delivers power in the cold, though the rated operating range is 32°F-130°F and capacity drops as it gets colder. Charging below freezing is blocked by the BMS to protect the cells. For uninterrupted cold-weather charging, choose the Heated variant.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q22\"\u003e\u003clabel for=\"q22\"\u003eWhat does the Heated version do?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eWhen connected to a charger and the internal temperature drops to 32°F, it self-warms to 34°F, then charging resumes automatically. The heater runs only while a charger is connected.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q23\"\u003e\u003clabel for=\"q23\"\u003eDoes the Heated version warm the battery while I'm running?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eNo. The heater is a cold-charging feature and operates only when a charger is connected, not during discharge.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q24\"\u003e\u003clabel for=\"q24\"\u003eDo I need the Heated version in a warm climate?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eUsually not. In warm climates the Standard version is the right choice. Choose Heated if you charge or store in sub-freezing conditions.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q25\"\u003e\u003clabel for=\"q25\"\u003eHow should I store it over winter?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eCharge it, disconnect it, and keep it cool and dry. Self-discharge is under 4% per month, so it holds a charge well.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"lbs-faqgroup\"\u003e\n\u003ch4\u003eWiring \u0026amp; configuration\u003c\/h4\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q26\"\u003e\u003clabel for=\"q26\"\u003eCan I wire two in series for a 24V trolling motor?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eSome owners do. Before wiring a series bank, confirm the exact series configuration and limits with Millertech, and use identical batteries with proper fusing. For most setups a dedicated 24V or 36V Millertech trolling battery is the cleaner solution.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q27\"\u003e\u003clabel for=\"q27\"\u003eCan I wire them in parallel for more capacity?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eConfirm parallel limits with Millertech before building a bank. Use identical batteries (same model, capacity, age) and correct fusing.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q28\"\u003e\u003clabel for=\"q28\"\u003eCan I run 12V accessories and a 24V trolling motor together?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eYes, typically with a combiner or the appropriate on-the-run charger. Contact us with your setup and we'll help you configure it.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q29\"\u003e\u003clabel for=\"q29\"\u003eCan I mix this with my existing lead-acid batteries?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eDo not mix chemistries within the same series or parallel bank. Keep lithium and lead-acid on separate circuits.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"lbs-faqgroup\"\u003e\n\u003ch4\u003eFitment \u0026amp; installation\u003c\/h4\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q30\"\u003e\u003clabel for=\"q30\"\u003eWill it fit my Group 31 tray?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eYes. It is a true Group 31 at 13″ x 6.75″ x 9″. A matching tray is available if needed.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q31\"\u003e\u003clabel for=\"q31\"\u003eWhat terminals does it use?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eM8 18-8 stainless bolts and washers. Torque connections to 10 ft-lbs. For multiple lugs you may need to remove a washer or use a slightly longer bolt.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q32\"\u003e\u003clabel for=\"q32\"\u003eThe supplied bolts seem short for my lugs what do I do?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eIf you are stacking several ring terminals, remove a washer or source a slightly longer M8 bolt so it fully seats into the copper pillar. Do not over-torque past 10 ft-lbs.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q33\"\u003e\u003clabel for=\"q33\"\u003eCan I install it myself?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eYes, if you are comfortable with basic battery wiring and fusing. Follow the manual, use correctly sized cables, and protect circuits with fuses or breakers.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q34\"\u003e\u003clabel for=\"q34\"\u003eIs the case waterproof?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eThe sealed case is IP65 rated with a rubber gasket and a top-mounted stainless breather vent to prevent condensation.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q35\"\u003e\u003clabel for=\"q35\"\u003eHow much weight does it save?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eAt 33 lb it is roughly 20-30 lb lighter than a comparable lead-acid Group 31, and replacing two batteries with one compounds the savings.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q44\"\u003e\u003clabel for=\"q44\"\u003eWill it fit and work in my Ranger, Skeeter, Phoenix, or similar bass boat?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eYes. As a Group 31 it fits the standard trays used across most bass and multi-species boats. Fit comes down to your Group 31 tray and your engine's charging requirements, so confirm both for your exact hull and motor.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"lbs-faqgroup\"\u003e\n\u003ch4\u003eOther applications, monitoring \u0026amp; warranty\u003c\/h4\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q36\"\u003e\u003clabel for=\"q36\"\u003eCan I use it for an RV or solar setup?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eYes. It works as a 12V dual-purpose battery for RVs, off-grid, solar, and tiny homes. Charge it with a lithium-compatible charger or solar controller.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q37\"\u003e\u003clabel for=\"q37\"\u003eDoes the Bluetooth app really help?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eYes. It shows charge percentage, voltage, current, and temperature so you know your available power before you launch, and you can monitor multiple batteries in one app.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q38\"\u003e\u003clabel for=\"q38\"\u003eHow long will the battery last?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eMillertech rates the Sport Series for many times the cycle life of lead-acid and backs it with a 10-year warranty.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q39\"\u003e\u003clabel for=\"q39\"\u003eWhat does the warranty cover, and who handles it?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eTen years, full coverage. If it stops working, Millertech repairs or replaces it with equal or greater value at no cost and covers shipping both ways. No proof of purchase required. Warranty service is handled directly by Millertech.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q40\"\u003e\u003clabel for=\"q40\"\u003eHow much is shipping?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eShipping is free, and orders ship directly from the manufacturer.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q41\"\u003e\u003clabel for=\"q41\"\u003eWhat's the difference between the 135Ah Dual Purpose and a deep-cycle-only battery?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eA deep-cycle battery is optimized for steady discharge and is not built to crank an engine. The Dual Purpose delivers both high cranking current and deep-cycle capacity from one battery.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"lbs-faq\"\u003e\n\u003cinput type=\"checkbox\" id=\"q42\"\u003e\u003clabel for=\"q42\"\u003eStandard or Heated which should I buy?\u003c\/label\u003e\n\u003cdiv class=\"lbs-a\"\u003e\n\u003cp\u003eChoose Standard for most uses, especially warm climates. Choose Heated if you charge, launch, or store in sub-freezing temperatures.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c!-- ================= TAB: WHY BUY FROM US ================= --\u003e\n\u003ch3\u003eWhy Buy From Us\u003c\/h3\u003e\n\u003cp\u003eChoosing a $900+ lithium marine battery is about more than picking specs, it's about matching the right battery to your boat, engine, electronics, and charging system, and knowing someone has your back if a question comes up. That's where we come in.\u003c\/p\u003e\n\u003ch4\u003eWe help you choose the right battery\u003c\/h4\u003e\n\u003cp\u003eNo two boats are set up the same way. Before you order, we can walk through your boat make and model, engine and horsepower, tray dimensions, number of displays, forward-facing sonar, trolling motor voltage, existing charger, and climate. Our goal isn't to sell you the biggest battery, it's to match the battery to your application, and to tell you plainly if a different configuration fits better.\u003c\/p\u003e\n\u003ch4\u003eSupport before and after the sale\u003c\/h4\u003e\n\u003cp\u003eReach out before ordering and we'll review your setup. We can help with choosing the right model, Standard vs. Heated, charger compatibility, Group 31 tray fitment, charging questions, basic installation guidance, product registration, and warranty support. Most questions come after installation, when you add another graph, upgrade a charger, or plan future electronics and we're here for those too.\u003c\/p\u003e\n\u003ch4\u003eGenuine, warranty-backed products\u003c\/h4\u003e\n\u003cp\u003eEvery Millertech battery we sell is a genuine, current-version product with full manufacturer-backed warranty coverage and original documentation. Millertech's 10-year warranty requires no proof of purchase and covers shipping both ways.\u003c\/p\u003e\n\u003ch4\u003eFast, secure shipping\u003c\/h4\u003e\n\u003cp\u003eYour battery ships securely packaged with tracking provided once your order is processed. Shipping is free.\u003c\/p\u003e\n\u003ch4\u003eStill not sure it's the right fit?\u003c\/h4\u003e\n\u003cp\u003eContact us before you order and we'll review your boat, engine, charger, electronics, sonar, trolling motor, climate, and any planned upgrades, then recommend the configuration that fits your setup. We'd rather help you get the right battery than sell you the wrong one.\u003c\/p\u003e\n\u003ch4\u003eWhat's included\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003eMillertech 12V 135Ah Dual Purpose battery (Standard or Heated variant selected)\u003c\/li\u003e\n\u003cli\u003eTerminal hardware (M8 18-8 stainless bolts and washers)\u003c\/li\u003e\n\u003cli\u003eBluetooth app access (iOS and Android)\u003c\/li\u003e\n\u003cli\u003eProduct manual and warranty documentation\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- ================= INTERNAL LINKING (populate with your handles) ================= --\u003e\n\u003cp class=\"lbs-note\"\u003e \u003c\/p\u003e\n\u003c\/div\u003e\n\u003c!-- ==================================================================================\n     JSON-LD: PRODUCT SCHEMA (two offers). Replace URL, image, GTIN, sku as needed.\n     ================================================================================== --\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003c!-- ==================================================================================\n     JSON-LD: FAQ SCHEMA (subset of key questions; expand to match visible FAQ as desired)\n     ================================================================================== --\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003c!-- ==================================================================================\n     IMAGE ALT TEXT (apply to each product image in Shopify)\n     ==================================================================================\n     1. Millertech 12V 135Ah Dual Purpose lithium marine battery, Group 31, item 12135-DP\n     2. Millertech 135Ah dual purpose battery dual terminals and Bluetooth Sport Series label\n     3. Millertech 12V charger compatibility chart for the 135Ah dual purpose battery\n     4. Millertech 12V 135Ah Heated dual purpose starting battery, item 12135-DPH\n     5. Millertech 135Ah battery installed in a bass boat as a single cranking and electronics battery\n     ================================================================================== --\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003c!-- ==================================================================================\n     GOOGLE MERCHANT CENTER FEED (Simprosys \/ GMC)\n     ==================================================================================\n     PRODUCT TITLE:\n       Millertech 12V 135Ah Dual Purpose LiFePO4 Marine Battery - Group 31, 1500 CCA, Bluetooth\n\n     DESCRIPTION:\n       Millertech 12V 135Ah Dual Purpose lithium (LiFePO4) marine battery. Combines 1500 CCA\n       cranking power with 135Ah of deep-cycle capacity in a single Group 31 case, so one battery\n       starts your outboard and runs forward-facing sonar, multiple graphs, livewell pumps, and\n       shallow-water anchors through a full day. Includes an integrated BMS, Bluetooth monitoring,\n       98% efficiency, low-temperature charging protection, sealed IP65 case, and a 10-year warranty.\n       Weighs 33 lb. Available in Standard and Heated (cold-weather charging) versions. Free shipping.\n\n     PRODUCT HIGHLIGHTS (5):\n       - 1500 CCA cranking with 300A peak for reliable outboard starting\n       - 135Ah deep-cycle capacity runs sonar, graphs, and pumps all day\n       - Lightweight 33 lb Group 31 replaces heavier lead-acid batteries\n       - Bluetooth app shows charge, voltage, current, and temperature\n       - 10-year full warranty with free shipping\n\n     ATTRIBUTES:\n       brand: Millertech\n       mpn: 12135-DP  (Heated variant: 12135-DPH)\n       gtin: [ADD IF AVAILABLE]\n       condition: New\n       color: Black (Standard) \/ [confirm Heated color]\n       material: Lithium Iron Phosphate (LiFePO4)\n       energy capacity: 135Ah (1.728 kWh)\n       voltage: 12V (12.8V nominal)\n       group size: BCI Group 31\n       price: 949.00 USD (Standard) \/ 989.00 USD (Heated)\n     ================================================================================== --\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003c!-- ==================================================================================\n     ORIGINAL-ASSET SHOT LIST (for Guldsha \/ photographer — build to boost E-E-A-T \u0026 AI)\n     Priority order:\n     1. Group 31 size + weight comparison graphic (33 lb lithium vs ~55 lb AGM)\n     2. Single-battery wiring diagram (crank + electronics off one Dual Purpose)\n     3. 24V and 36V trolling-motor wiring diagrams (dedicated battery, fused)\n     4. Battery-compartment install photos (real boat, straps in the molded grooves)\n     5. Terminal\/torque close-up (M8, 10 ft-lbs) + ring-terminal stacking note\n     6. Bluetooth app screenshots (SOC, voltage, current, temp)\n     7. Runtime chart graphic built from the \"Estimated runtime by setup\" table above\n     DEFERRED (separate projects, not launch blockers):\n     - \"What battery do I need?\" interactive calculator (dev artifact)\n     - Neutral brand-comparison article (NOT on-page; you sell Epoch\/Dakota)\n     ================================================================================== --\u003e","brand":"Millertech","offers":[{"title":"Standard","offer_id":48243789037826,"sku":"12135-DP","price":949.0,"currency_code":"USD","in_stock":true},{"title":"Heated","offer_id":48243789070594,"sku":"12135-DPH","price":989.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0723\/3660\/5442\/files\/Millertech_12V_135ah_Dual_Purpose_Standard_Model.webp?v=1785639977","url":"https:\/\/www.lithiumbatterysupply.com\/products\/millertech-12v-135ah-dual-purpose-lithium-marine-battery","provider":"Lithium Battery Supply","version":"1.0","type":"link"}