Evening Martin,

Apologies, I thought you speaking of both the inverter/ups as one unit.

The battery capacity would be the 8000 VA.

The inverter by itself is a little more involved. You need to know the VA of the motor plus the charge rate/capacity of the cells being used (assuming sealed lead acid).

Can develop a better load profile over the next few days if you need something prior to ordering.
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They will swing back to the belief that they can make people...better. And I do not hold to that. So no more runnin'. I aim to misbehave.