Buying a trolling motor battery is easy to get wrong because “12V vs 24V,” “100Ah,” “Group 24/27/31,” and “lithium vs AGM” all get mixed together online. The result: short runtime, unexpected shutdowns, or a system that feels weak late in the day.
This guide gives you:
- A clear way to choose battery type
- A practical sizing method that works even if you don’t know your motor’s exact amp draw
- A buying checklist you can send to suppliers or use for OEM sourcing
If you want the full runtime math and calculators, use our dedicated sizing guide here:
https://zjsaftec.com/lithium-battery/battery-size-for-trolling-motor-guide-voltage-ah-and-thrust-explained/
What does a trolling motor battery need to do
A trolling motor is a continuous load. That’s why “starting batteries” often disappoint in this role.
A correct trolling motor battery should deliver:
- Stable voltage under load so thrust stays consistent
- Enough usable capacity for your typical day, not just the first hour
- Repeatable cycling without rapid performance fade
- Safe current delivery at your motor’s peak demand
If your motor feels strong early and “lazy” later, that’s commonly voltage sag, not just “low charge.”
What types of trolling motor batteries are people actually buying
You’ll see three real-world choices:
What is the difference between LiFePO4, AGM, and flooded lead-acid
LiFePO4 lithium
- Often chosen for: lighter weight, flatter voltage, strong usable capacity, long service life
- Typical feel on the water: “more consistent thrust” late in the day
AGM
- Often chosen for: low maintenance lead-acid, decent durability, availability
- Typical feel on the water: reliable, but can still sag under higher load
Flooded lead-acid
- Often chosen for: lowest upfront cost
- Typical feel on the water: works, but heavier and more performance drop as it discharges
A practical buyer lens is not “which is best,” but:
- How often do you fish
- How long do you run the motor
- How sensitive you are to weight and voltage sag
- Whether your charging setup is compatible
How do you know if you need 12V, 24V, or 36V
This decision is not about “capacity” first. It’s about your motor’s required system voltage.
What voltage does my trolling motor require
Check the motor label or manual. Common patterns:
- 12V motors are common for smaller setups and moderate thrust
- 24V motors are common for stronger thrust and better efficiency
- 36V motors are common for high-thrust systems and larger boats
Do not try to “upgrade voltage” unless the motor is designed for it.
How many batteries do I need for 12V, 24V, and 36V
- 12V system: 1 battery
- 24V system: 2 batteries in series or one 24V pack
- 36V system: 3 batteries in series or one 36V pack
For series systems, it’s best practice to use matched batteries (same chemistry, same capacity, same age).
What size trolling motor battery do most anglers buy
A practical way anglers choose battery size without doing math
Most anglers choose based on three things:
- System voltage required by the motor
- Thrust class (how hard the motor can pull)
- How long they want to fish before charging
Below are “common buys” you’ll see repeatedly in the market.
Common battery sizes by voltage and “day length”
Think of this as a buying shortcut, not a guarantee. Wind, weeds, current, and speed change everything.
For 12V trolling motor systems
Most common “safe” choices:
- Short trips, calm water: 12V 50Ah to 80Ah LiFePO4
- Most anglers, half-day to full-day: 12V 100Ah LiFePO4
- Long days, strong wind, frequent high throttle: 12V 120Ah to 150Ah LiFePO4
Why 12V 100Ah is so common: it’s usually the best balance of runtime, weight, and cost for single-battery setups.
For 24V trolling motor systems
Most common choices:
- Typical all-day setup: 24V 100Ah LiFePO4 (as one pack)
or two 12V 100Ah in series - Long runtime priority: 24V 120Ah to 200Ah LiFePO4 (or expanded bank)
Why this pattern is common: 24V systems often deliver strong thrust while staying efficient, so buyers aim for a capacity that covers a full day without pushing deep.
For 36V trolling motor systems
Most common choices:
- Common high-performance baseline: 36V 60Ah to 100Ah LiFePO4
or three 12V batteries in series - Buyers who demand long runtime often expand capacity, but physical space and cost become major constraints.
What about Group 24, Group 27, and Group 31 sizes
“Group size” is physical size, not performance by itself. But it influences what people buy because it dictates:
- Battery tray fit
- Available Ah in lead-acid
- How many batteries you can physically mount
A practical rule:
- If your boat tray fits Group 24, you’re often limited on lead-acid capacity
- Group 27 and Group 31 allow larger lead-acid options, but also add weight
- Many anglers switch to lithium specifically because it can deliver strong usable energy with less weight in a similar footprint
If you’re sourcing for a boat brand or an installer, always confirm:
- Tray dimensions
- Lid clearance for terminals
- Cable routing space
A quick sizing direction by thrust class
This is the kind of “quick check” anglers use:
- Moderate thrust 12V setups: many buyers target around 100Ah LiFePO4 for all-day confidence
- Higher thrust 24V setups: many buyers target 24V 100Ah as a baseline all-day configuration
- High thrust 36V setups: many buyers target 36V 60Ah to 100Ah depending on how aggressively they run the motor
If you want the exact runtime math, that belongs in the sizing guide:
https://zjsaftec.com/lithium-battery/battery-size-for-trolling-motor-guide-voltage-ah-and-thrust-explained/
How do you buy a trolling motor battery without getting burned
This section is written like a buyer’s checklist you can actually use.
What to check on the motor side first
- Required voltage: 12V, 24V, or 36V
- Peak current draw or the motor model so it can be verified
- Typical usage: “mostly low throttle” vs “often high throttle”
- Any extra loads sharing the bank: fishfinder, livewell pumps, lights
What to check on the battery side
If you’re buying LiFePO4, ask for:
- BMS continuous discharge current rating
- BMS peak or surge capability (important for throttle spikes)
- Low-temperature charging protection strategy
- Cell grade consistency approach (how they control pack balance and variation)
- Warranty terms that match marine vibration and real use
If you’re buying AGM or lead-acid, check:
- Reserve capacity and discharge rating
- Real weight and handle design
- Compatibility with your tray and strap system
- Expected service life under deep cycling
What to check on charging compatibility
A huge percentage of “battery problems” are actually charging problems.
Confirm:
- Does your charger have LiFePO4 mode or correct settings
- Are you charging from shore power only, or also from an outboard alternator
- Do you need current limiting or a controlled charging device for alternator charging
- Are there any parasitic loads left connected during storage
If you don’t know your charger model, capture a label photo and send it—this is usually easy to confirm.
Why do trolling motor batteries shut off or feel weak late in the day
Here are the most common “real” causes:
Why BMS cutoff happens in lithium systems
- Motor peak current exceeds BMS limit
- Cable resistance causes voltage drop and triggers protection
- Cold charging protection prevents charging when it’s too cold
- Battery is undersized and you’re running near limits constantly
A cutoff is often a protection event, not a “dead battery.”
Why series systems fail when batteries are mismatched
In 24V and 36V:
- One weaker battery becomes the limiting factor
- Charging becomes uneven
- Runtime becomes unpredictable
For professional installs, treat series batteries like matched tires: same type, same age, same condition.
What is a smart buying checklist for trolling motor batteries
Copy and paste this checklist into your purchasing notes:
- Confirm motor voltage requirement
- Confirm motor model and expected peak current
- Choose chemistry: LiFePO4 vs AGM vs lead-acid based on usage frequency
- Decide runtime target: short trip, half-day, full-day, extended
- Verify physical fit: tray size, terminal clearance, strap/hold-down method
- Verify discharge capability: BMS continuous and surge for lithium
- Verify charging plan: shore charger compatibility and alternator strategy
- Confirm wiring and cable gauge for current level
- Confirm cold weather expectations and protection needs
- Confirm warranty terms and after-sales support
Looking for a trolling motor battery supplier for OEM, ODM, private label
Yes—this is the right place to introduce SAFTEC, because this section is where buyers are actively deciding who to source from.
Who SAFTEC is and what we supply
SAFTEC is a lithium energy storage manufacturer focused on LiFePO4 battery packs for marine and mobility applications. For trolling motor projects, we support:
- OEM and ODM battery pack development
- Private label branding and packaging
- 12V, 24V, and 36V system solutions
- BMS selection based on real motor peak current
- Custom pack shape, terminals, connectors, and mounting requirements
Our goal is simple: a pack that matches your motor, your charging method, and your real-use conditions, not just a label capacity.
What you can customize in an OEM trolling motor battery pack
Common customization items include:
- Voltage system and capacity range
- Continuous and peak discharge targets
- Low temperature charge protection strategy
- Bluetooth monitoring options
- Terminal and connector format
- Housing design and mounting features
- Label design, cartons, and private label requirements
We can also help you define a “no-surprises” spec so customers do not experience cutoffs, short runtime complaints, or charging incompatibility.
What information to send us for an accurate recommendation
To recommend the right pack quickly, send:
- Trolling motor brand and model
- System voltage required
- Peak amp draw if available
- Your typical fishing duration and conditions
- Available battery tray dimensions
- Your charging method on the boat
If you don’t know peak draw, we can estimate based on model specs and build the recommendation around safe margins.
How we handle documentation and export support
For international shipments and B2B orders, we support practical export documentation as needed, such as:
- Battery test and shipping documents commonly requested by forwarders
- Standard labeling and carton protection design
- Packing list and traceability information for bulk orders
Instead of listing “compliance” as a separate section, we integrate the needed documents into your order flow so sourcing stays simple.
Ready to source or build your trolling motor battery pack
If you are buying for your brand, distribution, or project, contact SAFTEC with your motor specs and target requirements. We’ll provide a configuration recommendation and quote based on real-world current demand and charging compatibility.
FAQ
What is the best battery type for a trolling motor
For many frequent anglers, LiFePO4 is chosen because it delivers more consistent usable voltage and strong cycle life when matched with the correct BMS and charger. AGM remains a practical choice for occasional users who want simple lead-acid behavior without maintenance. The “best” battery is the one that matches your voltage requirement, peak current, runtime target, and charging method.
What size battery for trolling motor is recommended for all-day fishing
A common all-day baseline many buyers use is:
- 12V systems: 12V 100Ah LiFePO4
- 24V systems: 24V 100Ah LiFePO4 or two 12V 100Ah in series
- 36V systems: 36V 60Ah to 100Ah LiFePO4 depending on throttle habits
For precise estimates, you need your motor’s amp draw and your throttle profile.
Do I need a deep cycle battery for a trolling motor
In most cases, yes. Trolling motors draw power continuously, and deep-cycle designs are built for repeated discharge and recharge. Starter batteries are designed for short bursts and can show faster performance drop in this use.
How many batteries do I need for a 24V or 36V trolling motor
- 24V: typically two 12V batteries in series, or one 24V pack
- 36V: typically three 12V batteries in series, or one 36V pack
For series systems, matched batteries help prevent uneven performance and charging issues.
Why do lithium trolling motor batteries sometimes shut off
Most shutdowns trace to mismatch rather than chemistry:
- Peak current demand exceeds BMS surge rating
- Cable resistance causes voltage drop under load
- Charging below freezing triggers protection
- Battery is undersized for real conditions
A properly matched pack avoids most of these issues.
Can I use my current charger if I switch to LiFePO4
Only if the charger has a LiFePO4 mode or correct adjustable settings. Many lead-acid chargers are designed around float behavior that does not map perfectly to lithium charging. If you share the charger model, compatibility can usually be confirmed quickly.
What should I send a supplier to get the right recommendation
Send:
- Trolling motor model
- System voltage requirement
- Peak amp draw if available
- Your typical fishing duration and water conditions
- Battery tray dimensions
- How you charge on the boat
This is enough for a supplier to recommend a safe BMS rating and capacity range without guessing.
