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Need help with batterybank  RSS feed

 
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Im trying to find out how long a 916 Ah 48V battery bank can drift something that requires 47 kwh/ day. at 230V ?
Can anyone here tell me how to figure it out, or if it's even possible.
Thanks
 
Posts: 5
Location: Bristol - UK
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Daniel,

Not sure what you mean by "can drift something" but if you mean "drive" or "power" then here's my guestimate at it - but I'm new to these kind of calculations so you might want to get these checked out by someone with more experience with battery banks...

47kWh/day is 1958.333Watts continuous. At 240v that's 8.160Amps continuous load. Assuming an inverter efficiency of 80% that's about a 10.2Amp draw on the batteries. So a 916Ah bank should last for around 90 hours without recharge.

Corrections to the above welcome - I want to learn how you folks calculate this!
 
pollinator
Posts: 684
Location: Richmond, Utah
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That's close, but you forgot to convert the voltage so;
10.2A*240/48=51A@48V then 916/51*.9(line losses estimate)=16.16hrs, but probably less due to voltage drift as the batteries come down, so my non-expert opinion would be around 12 hrs.
 
Steve Edwards
Posts: 5
Location: Bristol - UK
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Yeah, thanks Bill, I did forget to convert between voltages.
 
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