Charging a Chevy Volt with Classic 150 set up?

[balee123]

Hello all,

I currently have a backup system for powering our house using a Chevy Volt as the power source.  An inverter runs off the car's 12V battery, which is kept fed by the vehicles's main traction battery through a DC-DC converter.  The DC-DC converter can supply ~175A DC to the 12 V battery (probably more like 150A as my understanding is the car may used upto 400W.  The output of the inverter can be tied to the house breaker panel which incorporates a manual transfer switch.

The nice thing about this system is that with a full tank of gas and a full battery charge, I think we can probably last over a week with our current loads.

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I've been thinking about how to charge the Chevy Volt off grid, and use it's battery storage capacity if we have no access to gas and the grid was down for an extended period of time.

I understand that it is probably more efficient to store more gas, rotate it over time, and use the Volt's internal generator, but I'm also wondering if the following would work:

I currently have a grid tied system:

Inverters: Xantrex STRX2500 and STRX1500 wired in parallel.

Panels:
100W AP-100
Voc 20.1V
Vmp 16.1V
Isc 7.2A
Imp 6.2A

Panels are set up as 4 in series, 5 paralleled into STRX2500 and 3 paralleled into the STRX1500.

Power consumption while Volt is charging is 1440W @ 12A AC, or 960W @ 8A AC to charge the Volt (two different charging rates available).

I was thinking I could rewire the PV's DC output into a Midnite Solar Classic 150, hook the Classic up to 2 (bear with me) fully charged 12V batteries wired in series for 24V, then plug the Chevy Volt's EVSE ("charger") into a 24V/120VAC inverter to charge the car. Since the batteries would be fully charged, all the DC output of the panels could go to power the 24V inverter and charge the Volt, and hopefully have some left over to power the house during charging. The Volt would only be charged by the PV output and not the tiny battery bank.

(I'm assuming a 12V battery bank with a 12V inverter would not give me enough power with the Classic 150 to charge the Volt).

I understand that this is an extremely small battery bank and cannot really be drawn on. I'm thinking they will just be used to buffer the charge controller's output. I also understand that this system would require some serious monitoring so that charging only occurs during strong/peak daylight hours without clouds. I'm also not concerned about matching loads to getting a full charge everyday. In this kind of situation, one would just use whatever electricity they could generate and/or store. I understand that I may not get a full charge during the day depending on previous usage.

I figure with 5 hours of usable sun, we could generate and store about ~5kWh on days with no clouds. The Volt charges and stores at a rate of about 1kW per hour.

Will this work? Any suggestions?

[Wxboy]

I don't see any reason why this wouldn't work and if I had a Volt I would be trying it with my 12 volt inverter.  A 2,000 watt pure sine wave 12 volt inverter would work if you used heavy enough wires from the batteries to the inverter.  24 volt is better because it draws half as many amps through the wires. 

[niel]

this may not work. the reason for this is that the 24v battery arrangement would not supply enough overall wh to run the charger properly. it may work when charging the car is done during the time periods of nice sunshine as the car would just siphon off the power it needed from the system, but non sunny periods would rely totally on battery capacity.

remember the amps you depict are at 120vac and not 12vdc or 24vdc. at 24vdc you would need more than 5x the current and this will need to be sustained over many many hours of charging. after figuring the dc ah needed to sustain a long term charge, the battery bank itself would also need to be doubled at that point to prevent dropping the soc below 50%. faced with a huge battery bank at this point, will the pvs properly charge that battery bank?

it just isn't as simple as throwing a few batteries together and putting an inverter on it.