A 7- or 8-amp charger will never bring a battery that's been drained
significantly back up at a proper rate. This can lead to sulfation on
the plates, shortening the lifespan and/or storage capacity. If the
battery is never drained down by more than 10%, perhaps the small
charger can keep it topped up. I'm running 40A on a 200ah battery bank
that so far has never been below 70% capacity.

On 8/1/2013 8:57 PM, Steve Williams wrote:
> At 05:41 PM 8/1/2013, Karl Mullendore wrote:
>> That (7.2-amp) charger is far too small fr anything much larger than a
>> lawnmower
>> battery. I'd recommend a 20-30A Iota charger.
>
> Karl, tell me more!  My little 8-amp Prosport charger seems to do fine,
> even with the Engle fridge running.
>
> http://www.amazon.com/exec/obidos/ASIN/B001BSUR2Q/sbw/
>
> (Not to mention I see that same charger in a lot of boats, all with
> large house batteries.)
>
> My house battery is an Interstate SRM-29, about 100 amp-hours.
>