How Many Amps Does My Battery Charger Need To Be?

[Catch and Grease]

I don't know the exact specifications on my battery but its a dual purpose battery I'm using for starting and running the trolling motor, its a 12v. I was thinking of getting a 12v 2amp charger, will that work? Do amps matter that much or will a 2 amp charger work for most batterys?

[J Francho]

Think you ned some basics here.

http://www.batterystuff.com/kb/articles/battery-articles/battery-basics.html

A 2 amp will charge any battery that matches the type and voltage, but if it's a large capicity, it might take a while.

I use a 1.5 amp charger for a 7 ah battery in my kayaks. The bass boat has a three bank, 10-10-10 amp charger - one 10 amp bank for each of the three batteries.

[Ozark_Basser]

2 amp will take a while, but it will work. I have a 6 amp charger.

[Catch and Grease]

Think you ned some basics here.

http://www.batterystuff.com/kb/articles/battery-articles/battery-basics.html

A 2 amp will charge any battery that matches the type and voltage, but if it's a large capicity, it might take a while.

I use a 1.5 amp charger for a 7 ah battery in my kayaks. The bass boat has a three bank, 10-10-10 amp charger - one 10 amp bank for each of the three batteries.

Thanks for that link, tons of good information!

[WIGuide]

I would think you'd want at least a 10 amp or close.

[J Francho]

Also, it's a concern that your using the same battery for cranking and deep cycle purpose.

[BKeith]

The real answer is the manufactures recommend 10% of the rated capacity.  Typical dual purpose and deep cycle TM batteries range between 75 Ah for group 24 and 120 Ah group 31, so that would be between 7 1/2 amps to 12 amps, depending on the battery.   Personally, I would never repeatedly charge a group 24 or larger flooded cell battery with a 2 amp charger, all you are doing is killing the battery.   You can do that with AGM's but not flooded cell.

[Catch and Grease]

Also, it's a concern that your using the same battery for cranking and deep cycle purpose.

Isn't that the whole point of a dual purpose battery, why would it be a bad idea? I geuss its probably a better idea to have a battery for each but I couldn't afford it. So I just got one dual purpose.

[Way2slow]

Yes, the dual purpose is designed for double duty, it's capable of giving a short burst of high amps to crank the motor while still maintaining a deep cycle capability. I always run dual purpose cranking batteries because of the all the stuff running while the motor is not.

I think the concern would using the cranking battery as a TM battery, but in your case, it's not a real problem. With your motor, if the TM drains the battery to the point the starter won't crank it, you have a motor with a pull rope and is easy enough to pull start.

Actually, for no more cranking amps than your motor needs, you can use a straight deep cycle TM battery with no problems. It's when you get into the big V-6s and especially the DFI motors that really need the big cranking amp numbers that trying to do that would get you in trouble.