Why are my boat batteries dying so fast?

[MickD]

You are charging them between fishing trips, right?  And not depending totally on the engine to charge them?  

[Darth-Baiter]

do you have a multimeter?

 

i once found out one of my friends batteries was defected.  he bought three at once, but they drained fast.  one bad battery will drag down the other two quickly.  (at least that was my theory)

 

i think everyone with car batteries or boat batteries should have a multimeter. 

[Big Hands]

I'm curious to know how this turned out. Group 24 to power a 21' fiberglass boat with a 24v, 70 lbs thrust motor seems underpowered to me. As I understand it, a larger trolling motor run on a lower power setting (to achieve the same power to the prop) is more efficient (uses less battery).

 

However, if he was truly mostly using the lowest settings, even the Group 24's should last longer than 4-5 hours. I think if he wants to continue with the 70 lbs 24v trolling motor on a 21' fiberglass boat, he should consider running Group 31 batteries. Group 31 deep cycle batteries can provide up 100 - 130 ah capacity vs Group 24 which can provide up to 70 - 85 ah capacity. 

 

To be tournament ready, that 21' fiberglass boat should be equipped with three Group 31 batteries and a 36v trolling motor with over 100 lbs thrust. This will be more important on some days than others, but that 24v 70 lbs TM on your boat will impact your ability to fish how you want to at some point or another.

 

With all of that said, if money is tight, (and I have to do this myself at times) you do what you gotta do to get by and be happy you have the opportunity to fish high school tournaments at a national level. Kudos to your family to be able to provide you this very extraordinary opportunity. It's good to see that you are interested enough to learn for yourself, and I'm sure your pops is doing everything he can to support you.

[WRB]

2 group 24’s in series are too small for the TM, you need 2 group 31’s AGM’s for a 21’ tournament bass boat. Gr 24 is marginal cranking battery if multiple Sonars are in use.

You may have something drawing current when garaged or your charger isn’t putting out 10 amps per battery. Always charge the night before using.

Tom

PS, you can exchange name brand batteries anywhere they are sold.

3 bank Norco Genius onboard charger is good.