What Size Lithium Battery for a Trolling Motor
Answer
Sizing a lithium battery for a trolling motor
The short answer
Match the voltage to the motor first, because that part is not negotiable. Then pick amp hours against how you actually fish, not against the best day you ever had. Because lithium gives you the full capacity rather than half of it, a smaller number on the label often replaces a much bigger lead acid bank.
What voltage lithium battery does my trolling motor need?
Whatever the motor is rated for. A 24V motor needs 24V and a 36V motor needs 36V.
There are two ways to get there. A single battery at that voltage, or smaller batteries wired in series: two 12V in series make 24V, three make 36V. LBP supports up to four in series, so any of the common trolling motor voltages is reachable either way.
The single battery route is usually simpler, lighter in the hull and easier to monitor. The series route can make sense when space is awkward or when you already own part of the bank.
How many amp hours do I need for a full day on the water?
Start from how many hours the motor actually runs, not how many hours you are out.
A trolling motor spends much of the day off or barely turning. What drains a bank is sustained run at speed, fighting wind or current. The honest way to size is to think about your hardest realistic day rather than an average one, then choose the capacity that covers it with something left over.
This is where lithium changes the arithmetic. With lead acid you buy roughly double the capacity you intend to use, because taking one below half its rating shortens its life sharply. With lithium you use the whole thing, so a 100Ah lithium battery does the work of a much larger lead acid bank and does it at about 70 percent less weight.
Does a lithium battery really hold power better through the day?
Yes, and this is the difference people notice first.
Lead acid voltage sags as the battery empties, so the motor you have at hour six is not the motor you had at hour one. Lithium holds consistent voltage the whole way down, which means the last run back is the same speed as the first. That is a fishing difference rather than a spec sheet difference.
What does the weight saving actually do to a boat?
It moves the hole shot, the ride and the payload all at once.
LBP batteries average about 70 percent lighter than the lead acid they replace. On a bass boat a three battery 36V bank is the single heaviest thing in the back of the hull, so taking most of that out changes how the boat sits, how fast it gets up, and how much fuel it burns getting there.
What is the mistake people make sizing a trolling motor bank?
Buying on the amp hour number alone and ignoring what the battery does at the bottom of its range.
Two batteries rated the same can behave differently in the last quarter of the day, and that quarter is when it matters. The other frequent mistake is a charger that was fine for lead acid and is wrong for lithium, which quietly undercharges the bank for a season before anyone works out why the runtime is short.
If the answer is not obvious, size the bank with somebody who builds them rather than against a chart.
Can I run Bluetooth on a trolling motor battery?
Yes, several LBP batteries carry it, reporting into the Battery Genie app on iOS and Android.
On the water the useful part is knowing state of charge before deciding whether to make one more drift. Checking a phone beats guessing from a needle, and it beats opening a hatch in a chop.
Can I use my existing charger?
Only if it is a lithium charger at the right voltage.
LBP recommends its own lithium smart chargers at the matching voltage, and those carry a one year manufacturer’s warranty. Where a battery is charged from an inverter charger instead, the profile matters: bulk at 14.4V, absorb at 14.6V and float at 13.6V is the shape to aim for, and nothing should go above 15V. If your charger has no custom setting, pick the closest profile under that ceiling.
Where should the battery be mounted on the boat?
Somewhere water drains away from rather than collects in.
LBP batteries are IP65 rated, so rain, spray and washdown are fine. Immersion is not: the silicone seal can fail if a battery is submerged, and submerging one voids the warranty. A bilge that occasionally holds water is the wrong compartment.
How many batteries can I wire together?
Four in series and four in parallel is the supported maximum.
Series raises voltage, parallel raises capacity, and most trolling motor setups only need one of the two. Anything more complicated than that is worth a conversation before the wiring goes in, because a series arrangement wired wrong damages hardware rather than just failing to work.
What else is on this site worth reading?
- The lithium battery guide covers voltage, amp hours and BMS in
general terms.
- Marine batteries goes into house banks and electronics
alongside the trolling motor.
- LBP compared with Dakota Lithium is the page
to read if you are deciding between brands.
Talk to someone who builds these
LBP builds custom packs as well as shipping standard sizes, and the team will size a bank to the boat, the cart or the rig before anything is bought.
Contact the teamCall 727-223-9831
Keep reading
- Choosing a lithium battery, without guessingHow to pick a lithium battery by voltage, amp hours and application, what a BMS actually does, how charging differs from lead acid, and where the limits are.
- Comparing Lithium Battery Power with Dakota LithiumAn honest way to compare trolling motor and deep cycle battery brands: cells, BMS, series and parallel limits, custom builds, and what to ask either company.
- All guidesEvery guide on lithiumbatterypower.com in one place.
Last reviewed 2026-09-16Lithium Battery Power