[thingstodo]

I managed to snag a lot of batteries, deep cycle batteries (3), an agm (1) and 3 starter batteries (720 - 850 CA) for a pretty good price. The one deep cycle, a Motormaster Nautilus, is not in the best shape - it is rated at 50 ah RC and started out at 12.07V. I charged it with a 6A charger for 12 hours and it had not 'finished'. It ended up at 12.93 after resting for an hour. The other deep cycles (Optima yellowtops) began as 13.06V and 13.08V. Those might have been removed from the shelf and surplused without being used. The AGM does not appear to be a brand name. It's RC is 190 and it began at 12.84V. I haven't gotten around to charging that one yet.

The two Optimas will likely run one DC/AC inverter each and I'll chain the high voltage DC (150V within the inverter) together to get 300 VDC. I need to test what current the Optimas will supply, and for how long.

The inverters will draw about 250A max for 30 - 60 seconds if the battery can supply that and stay over the cut-out voltage of 10.8 VDC. That would give me about 18A at 150 VDC output.

I have an older deep cycle that was on my boat - a Costco Kirkland deep cycle. I'll put that one in parallel with the Motormaster Nautilus and drive the larger DC to AC inverter with them (if I can get the inverter working - it was also surplus and last time I looked at it, the control board did not do anything. The transformers and transistors looked OK).

The larger inverter is rated for 5000W continuous, 10,000W surge. If I limit that to 250A in at 12V and get 18A out of it at 150VDC then the VFD can run on 450VDC. That's enough to do some low-speed testing on the 40 HP motor.