building a trolling motor battery from prius packs

I have no idea how you would charge them. I suspect you will need to charge each one separtely with a charger designed for NIMH.

In a Prius, they never get less than 40% or more than 80% charged, if you hope they last long, you will need to enforce this in your application.

 

You couldn't use a whole Prius battery for a 24V system without inverter electronics, so you would end up splitting up the pack and using individual modules. If you are willing to do that, you would be better off buying NiMH batteries directly.

Tom

 

Three modules in series gives you 24v when fully charged and about 21 when discharged but not deeply enough to risk the modules. The battery would then have only about 3-4 Amp Hours of usable capacity. You can put groups of modules in parallel for more capacity, but that has to be done very carefully. I suggest that you consider getting a 24 volt LiOn battery made for an electric bike. For example:
http://www.ebay.com/itm/24V-10A-E-B...Cycling_Parts_Accessories&hash=item19d0b2118f

JeffD