How to choose the correct battery for a 24v or 36v trolling motor?
LiFePO4 batteries have many advantages over traditional Lead Acid batteries. Longer operating times, weight savings and many more years of operation are just to name a few. All Amped Outdoors LiFePO4 batteries listed below have a built in BMS (Battery Management System) which will protect your battery from overcharging, discharging too low, high temp cutoff, short circuit, and has built in cell balancing technology. Make sure to check out the bottom on this page to see the graphed out power draw of a 36V system when we put it to the test!
Sealed Lead Acid "Flooded" batteries can be up to 50% efficient and AGM can be up to 80%. This means you can expect to get 50-80% of the rated capacity. Our LiFePO4 batteries will give you 100%+ the rated capacity when new out of box.
Today we are finding new motors with brushless technology drawing less power. Garmin and Lowrance will typically draw less than traditional brushed motors.
Here is a helpful comparison for choosing the right battery for your setup!
50-60Ah LiFePO4 - Similar Capacity to a group size 27 AGM and group size 31 Flooded.
80Ah LiFePO4 - Similar capacity to a group size 31 AGM or 50% more capacity than group size 31 Flooded.
100Ah LiFePO4 - 20-30% more capacity than a group size 31 AGM and double the capacity of group size 31 Flooded.
24V Systems: Light users 24v 50AH. Moderate users 24v 80AH. Heavy users 24V 100AH (2 24v 50AH in parallel).
36V Systems: Light users 36v 50AH. Moderate users 36v 60Ah-80AH. Heavy users 36V 100AH (2 36v 50Ah in parallel)
The following graphs were completed by Steve Becker from WalleyeTech Guide Service. The results show how much power each speed on a 36v system on a pretty typical boat (Ranger 612FS) on an average calm day on the water. Weight, wind, current will all play a role in how much power your setup will draw, use this in consideration when choosing the correct battery.
Charts below are on a Ranger 621FS with a 36V 112# Ultrex using 36v 100Ah Capacity!