24V dc Marine Trolling Motor Battery Build

[silvertalon]

Hi all, I'm new here and originally researched a solar system and EV build so I'm all in on this exciting stuff but 1st I want to build a LifePO4 battery system for my bass boat trolling motor, just to get started in battery building etc. Looking to build 2- 12 v 100 ah batteries using 5- 3.2v 20 ah cells for ea. I'm wanting to wire them in series for my 24v trolling motor. Reason being is I may change to a 36v motor in the future meaning I'd just need to add a 3rd battery. I have a few questions: Is the 3.2v cell a standard or, can I find higher v rated 20ah cells like 3.4 or, 3.6v? Reason I ask is I remember reading that these motors can perform better at 14v plus. Not essential but might mean more power output. 2, is there any benefit to building a single 200ah 24v battery vs. the 2-12v 100ah batteries wired in series? My thinking is that if one battery fails or need service I can change one out or simply have a 3rd 12v pack for a spare or a jumper for my cranking battery if needed. Also, I can still use a 2 or 3 bank 12v onboard digital charger (12v per bank), rather than investing in a 24v charger? 3, If I build the 2-12v batteries in series, will I still use a 8s BMS or do I use 2-12v BMS's? Also, where do I find BMS' and low voltage cut-out sw and the componants I need for a build? Hope the questions are clear etc. I appreciate any help and direction in my 1st exciting build. Thanks to all!

 

[BroomJM]

I have recently built two 100AH LiFePO4 batteries and had the exact same requirement in mind. I also wanted a weather-resistant case as we will use these for camping, ice-fishing, and in our smaller boat, with a 12v trolling motor.

I bought the batteries pre-configured from Lynx. These come with a Daly BMS, which includes low-temp charging protection and a bluetooth dongle so you can connect with your phone. These can be connected in series for 24v.

Below are a couple of pictures showing the batteries. I got the cases from Amazon and the terminals from a local electrical supply store. These weigh in at 24.4lbs and I'm charging them with a Neco Genius 10A (5Ax2) charger with a lithium profile built in.

I am waiting for the MPP 2724 inverter/charger to come in. That unit is truly all-in-one, with several 110 and USB outputs on the side of it.

Please let me know if you have any questions.