Inverter+battery bank combo question

[flynbanjo]

I am finally getting around to installing a battery bank in the bus.  So far we have been getting by with a 12KW generator or the shore chord.  Given all the usual loads that one would run off an inverter, does 4 8D agm batteries and a Magnum 4024 inverter seem like a reasonable combination?  I guess I am mostly concerned with inverters ability to charge the batteries in a reasonable amount of time.

Thanks

Steven

[bevans6]

You need to make a list of your "usual loads".  The killer app for an inverter is usually one or two air conditioners.  The Magnum can run them, but not for long on batteries, guessing one to one and a half hours on four 8D deep cycles to 50% SOC.  If you don't have the air conditioners or don't need to run them from battery, then you have a different scenario.  I like the Magnum, I just bought a 4024 myself, I have a roof-top AC that I run on the road to justify it, but if I didn't have that load I would have no more than a 2,000 watt inverter.  Back of the envelope calc, four 8D's is 500 AH at 24 volt, 20% max charge rate is 100 amp and the Magnum 4024 has a 105 amp charger, if you have shore power to support it.  This doesn't mean it still won't take 8 - 12 hours to get to 90% SOC and another 8 hours to get to fully charged, that's just what batteries like.  AGM is a different story.

Brian

[Nick Badame Refrig/ACC]

Hello Steven,

Brian has all good info for you... You really need to add up all your loads and do some math
to come up with a "good for you" battery bank.

Maybe this link will be of some help.
http://www.solar-electric.com/deep-cycle-battery-faq.html
It may give you an idea of how long the AGM's will take to charge on the Magnum.

Nick-

[TomC]

I have 2-8D AGM batteries, and while they are great batteries, I'm tired of the weight. On my truck conversion, I'm using L16 batteries at 6v and 400amp/hr each. They weigh a more manageable 115lb each compared to the 165lbs of the 8D's. 4-8D's will get you 1020amp/hrs at 12v. Running 6 L16's will get you 1200amp/hr at 12v. The L16's are about 5 inches taller then the 8D's. I believe the 6 L16's will have a smaller foot print then the 4-8D's.  Good Luck, TomC

[flynbanjo]

Thanks for advise.  I think you have me pointed in the right direction.

Steven