Battery size

[Reddirt]

I'd like to buy a battery.
I'm leaning towards a deep cycle battery (maybe AGM). But, my
question is how big a battery will I need.

How many amp-hours?

Thanks,
Reddirt

[dhazard]

What are you going to run and how long?

[Reddirt]

My 12v system would run:
1) 3 inside lights - maybe 2 hrs at night
2) Dometic Electro-Gas Refrigerator - run it in 12v mode while driving
3) Fantastsc fan or one of the clones - might run it for a few hours per day

That's all I can think of right now.

Thanks,
Reddirt

[Unkl Ron]

I'd get a deep cycle 75 AH battery. Get a "known brand" battery and it'll last for years.

Note: The Amp Hour rating tells you how much amperage is available when discharged evenly over a 20 hour period. The amp hour rating is cumulative, so in order to know how many constant amps the battery will output for 20 hours, you have to divide the amp hour rating by 20. Example: If a battery has an amp hour rating of 75, dividing by 20 = 3.75. Such a battery can carry a 3.75 amp load for 20 hours before dropping to 10.5 volts. (10.5 volts is the fully discharged level, at which point the battery needs to be recharged.) A battery with an amp hour rating of 55 will carry a 2.75 amp load for 20 hours before dropping to 10.5 volts.

[Gerdo]

First, you must get a deep cycle not a standard "Starting" battery. You will kill a starting battery in no time. I bought one from Wal*Mart. It is a 110 amp Deep Cycle and I think it cost me around $50-$60. They also have a smaller one. It is a "wet" battery. There are a few truly "Sealed" batteries (Optima and ProComp). Most are wet and will spill if turned upside down and will offgas when charged. I would keep a wet battery in a tongue box (that is where mine is) or something similar. The sealed one could go inside if needed.

By the way, there are only two manufactures of "car" batteries.

[Reddirt]

I bought a Kirkland Deep Cycle Marine 85 AMP Hour from Costco.
I'm going to keep it outside in a battery box.

Thanks for the help.

Reddirt

[mikeschn]

I'm going to buy the biggest deep cycle battery I can afford!

[boomboomtulum]

This is the Battery I purchased, photo is a little fuzzy but it's made by Exide, I have run lights during construction now for 20-25 hrs. and have yet to plug in the convertor to charge it. I'll find the specs. and post those as well. Dave

http://www.exide.com/products/marine_rv ... cycle.html