Hey everyone

I just recently installed a 65lb thrust minnkota riptide (24 volt) on my 18' seapro. now im getting ready to choose 2 batteries and installed them in my center console.

In my owners manual it says that over 100 amp hours is recommended. would two 50 amp hour batteries equal 100 amp hours??? also.. I fish on average about 3 times a week, but I rarely fish more then three hours, and I dont think I will use the trolling motor for more then an hour on most occasions. would I really need 100+ amp hours?? I have a few 24 group battery boxes in my shed, and they would probally fit better in my center console. I would get a couple 27 group batteries (or more) if I needed them.....What do y'all think???

thanks  

If you know the amp draw of the TM it's very easy to figure. Running on high, if your TM pulls 50 amps, you would get about 1 1/2 hours run time. You can't use the full AH capacity to figure your run time because at a 50 amp draw, that 100 AH battery becomes about an 80 AH battery. Plus you should never draw a bettery down fully, you should not draw one down below 20% charge or 12 volts. Now if your only running 50% thrust and drawing 25 amps, then the Ah capacity of the battery is back closer to 100 AH and you can run approx 3 1/2 hours on a 100 Ah capacity.

So, two 95 - 100 Ah group 24 batteries should give you want. Just remember, in series the two batteries provide 24 volts but they still only have the Ah capacity of one battery.

In series two equal batteries will provide twice the voltage but at the same capacity as one battery.

I parallel, they will provide the same voltage as one battery but at twice the Ah capacity.

Thanks for the reply Ben!

Do they make 100AH batterys in 24 group size? All the ones I saw in west marine that were over 100AH were 27 group

I haven't bought or looked at a group 24 in so many years I couldn't say.  I know they used to make them in 95 and you could find a few 100 Ah.  The problem you run into when stuffing that many plates into a group 24 case is they have a tendency not to last as long.  The plates swell as the battery ages  (that's why you see the sides bulging on an older battery) and the group 24, 100 Ah compresses them so much more they have a tendency to short out sooner than what a group 27 will with the same capacity.  

From what you describe though, I think if you can find two 95 Ah group 24's you would be in good shape.