Battery capacity

[pabraam]

What is the rule of thumb for the required (or minimum) capacity of a battery-bank in order to be able to invert (Mastervolt/Victron invertor) 12V > 230V and deliver 1500 Watt (peak 2000 Watt), without 'melting' my batteries.
Peter

 

[Maine Sail]

What is the rule of thumb for the required (or minimum) capacity of a battery-bank in order to be able to invert (Mastervolt/Victron invertor) 12V > 230V and deliver 1500 Watt (peak 2000 Watt), without 'melting' my batteries.
Peter

If you have a 1500W load then 1500W / 11.5V = 130A

Now add inverter inefficiency @ 15% - 130A X 1.15 = 149.5A (approx varies by brand/model)

Now correct for Peukert (assuming 77F battery temp / 400Ah bank / 1.25 Peukert)

Peukert corrected load on battery approx 250A at 77F for a 1500W load at 11.5V.

You will probably want a minimum of 400-600Ah's if you plan to draw 1500W for more than a few minutes.. For just a two minute microwave blast at that load a 200Ah bank could suffice but you may still tap out on low voltage..

 

[pabraam]

Thanks Maine, also for the quick answer. My 2x100 AH AGM house (=boat) batteries will be 7 years old this year, so I now know what to plan for.

 

[Bill Roosa]

I agree with MS and if you know the AC load and how long you intend to use it between recharges that will specify the battery bank minimum (for the AC, still need some storage to power the DC loads) size.
Also I think Main did not catch your in Europe and using 230 V ac and not the US 115 Volt ac.