Marine Lithium Batteries
Sealed LiFePO4 deep-cycle packs built for the transom: full usable capacity, flat voltage to the last hour, and half the weight of the flooded bank you are replacing. 12V, 24V and 36V systems, all maintenance-free.
- 100% usable capacity — no 50% lead-acid penalty
- Up to 60% lighter than flooded deep-cycle
- Sealed, maintenance-free, no off-season watering
- 10-year Promise series warranty, ships free from the USA
- Sealed & maintenance-free
- Flat voltage all day
- Bluetooth BMS monitoring
- US-based support
- Fast free shipping
Match your system voltage
Stay with the voltage your trolling motor and house circuit already run — 12V, 24V or 36V. Never mix lithium and lead-acid on the same bank.
Size to your day on the water
Use the sizer below: motor thrust, hours out and typical throttle. Most anglers land on a 105Ah 12V pack.
Charge it right
Use a lithium-profile charger. Lead-acid chargers will not bring a LiFePO4 pack to full state of charge.
SaleBlueMax Marine 12V 195Ah LiFePO4 Deep Cycle Battery (Group 27)
Sale price $62900 USD Regular price $69900Unit price
Sale12V 100ah Fleet Lithium Engine Starting (Group 27)
Sale price $53900 USD Regular price $59900Unit price
SaleBlueMax Marine 12V 200Ah LiFePO4 Deep Cycle Battery (Group 27)
Sale price $62900 USD Regular price $69900Unit price
SaleBlueMax Marine 12V 105Ah LiFePO4 Battery (Group 24)
Sale price $35900 USD Regular price $39900Unit price
SaleSale price $94500 USD Regular price $1,04999Unit price
Size it right
How much battery does your boat actually need?
Trolling motors pull hard all day and lead-acid gives you half its rating before the voltage sags. Size the pack to your motor, your hours and your water — then run the whole day on one charge.
Size your marine pack
—
Estimate based on ~1A per lb of thrust at 12V and 80% usable depth of discharge. Message us with your rig for an exact recommendation.
100% usable capacity
A 100Ah lead-acid bank gives you 50Ah before it sags. A Fleet Lithium 105Ah pack delivers the full rating, every trip.
Half the weight
Drop 60+ lbs off the transom versus flooded lead-acid and get it back in hull speed and range.
Flat voltage all day
Lithium holds voltage to the end of the charge, so your motor pulls the same thrust on the last hour as the first.
5,000+ cycles, 10-year warranty
Sealed, maintenance-free and IP-rated for the marine environment. No watering, no acid, no off-season top-ups.
Recommended Fleet Lithium marine batteries
BlueMax Marine 12V 195Ah LiFePO4 Deep Cycle Battery (Group 27)
12V 100ah Fleet Lithium Engine Starting (Group 27)
BlueMax Marine 12V 200Ah LiFePO4 Deep Cycle Battery (Group 27)
BlueMax Marine 12V 105Ah LiFePO4 Battery (Group 24)
- 5,000+ cycle life
- 10-year warranty
- 300A continuous discharge
- Sealed & maintenance-free
- Ships from the USA
Buyer questions
Marine lithium FAQ
What size battery do I need for my trolling motor?
Can I replace my lead-acid battery with lithium directly?
Do I need a special charger?
Are these batteries waterproof?
Will lithium work in cold weather?
How long will a Fleet Lithium marine battery last?
Trending Best Sellers
View all-
SaleFleet Lithium 51 Volt Battery Bundle for Polaris Ranger EV (2010–2024)
Sale priceFrom $2,42900 USD Regular price $2,69900Unit price -
Sale76.8V 105Ah Fleet Lithium Battery Bundle — NexGen BMS
Sale price $3,41900 USD Regular price $3,79900Unit price -
Sale76.8V 168Ah Fleet Lithium Battery Bundle — NexGen BMS
Sale price $4,22900 USD Regular price $4,69900Unit price -
Sale51V 105Ah Fleet Lithium Battery — NexGen BMS
Sale price $2,11400 USD Regular price $2,34900Unit price -
SaleTextron / Tracker Prowler EV (2017-Current) (72V) Fleet Lithium Conversion Kit
Sale priceFrom $3,40200 USD Regular price $3,78027Unit price -
Sale76.8V 105Ah Fleet Lithium Battery — NexGen BMS
Sale price $2,96900 USD Regular price $3,29900Unit price
Let customers speak for us
GREAT SERVICE
Awesome kit. We Live in a very cold climate, our ranger gets a ton of use year round and especially during the winter so the cold weather performance was a must for us. We've had the kit installed for about a year now and it's been perfect. Customer service has been super helpful the one or two times we had questions and we've got a couple of neighbors who run the kits as well and they say the same thing. Kevin and his crew are really top notch!
The 12V voltage reducer corrected the unstable behavior that had affected the lights and other accessories. The output has remained steady through regular use.
The 51V replacement charger is easy to keep available as a backup and works without unnecessary controls. The battery reaches a complete charge consistently during normal use.
The Polaris Ranger EV bundle lined up well with the intended mounting area and the connections were easy to identify. Once installed, the vehicle felt smoother and more consistent through normal use.
The 51V replacement charger connected as expected and has charged the compatible battery consistently. The status indicators are easy to follow, and the unit feels solid in regular use.
Easy installation and great technical support.
After installing the Club Car 48V kit, throttle response felt more immediate and the vehicle no longer felt sluggish late in the charge. The cleaner battery compartment is another welcome improvement.
Cabels look great. Will be installing them by the end of the week. Frank
The BlueMax 200Ah marine battery has provided steady power for onboard electronics and normal time on the water. It is easier to handle than the older battery and has required very little attention between trips.
The parts for the EZGO TXT kit were organized clearly and the installation sequence made sense. The finished setup looks tidy and removes the routine upkeep of the old battery bank.
The 76V replacement charger replaced the previous unit without requiring a complicated setup. Charging has been predictable, and the connector fits securely.
The plug on the 51V replacement charger seats firmly and the unit maintains a normal charging cycle. The battery has been ready for use each time charging is complete.
The parts for the EZGO RXV kit were organized clearly and the installation sequence made sense. The finished setup looks tidy and removes the routine upkeep of the old battery bank.
The 12V voltage reducer provided a clear path for running standard accessories from the higher-voltage battery system. The result has been reliable and easy to service.