Charging our cars with 3000W Inverter

I am always willing to support a fellow Pipper

 

It would be prudent to derate the inverter at least 20%, giving you 1200 watts. Also, if the batteries are good for 15 amps at the 5 hour rate, you will need at least 9 to get the necessary amperage...better would be 10. If you are serious about wind, you might look into some large Trojan (or equivalent) deep cycle batteries. They come in 6 volts, so you would need to series two for 12 volts, but they have storage ratings into several hundred amp-hours with discharge rates to match.

 

People don't seem to understand that while a deep cycle battery can, through an inverter, put out 120 volts, it requires 10X the amperage at the battery side to get X amps on the inverter side. The battery pack in the PIP is small by EV standards, but *huge* by 12 volt battery standards. You need 120 amps - per hour! - battery capacity just to get the 12 amps the PIP charger wants, and that's times three hours. So you need 360 amp-hours (AH) of capacity to charge the PIP. But wait: lead-acid batteries have inherent issues (high internal resistance, damage if discharged too deeply) that mean you have to double the capacity to get what you need, long-term. So now we're up to 720AH of battery storage, which I'd round up to 1000AH, to allow for the battery degradation that will occur over time. That's a lot of batteries, or some very large ones...

 

And now that you have that necessarily huge nice person bank of Trojan batteries don't forget the expense of the electrical ventilation system for the off gassing hydrogen. Apart from all of this complexity it does make me wonder how much loss there'd be going from DC wind generation to battery storage to AC inverter to the Pip's charger that again converts the AC back to DC .... whew!
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I have a small solar energy setup in my RV. I have 4 Trojan deep-cycle batteries, which are rated to store 3.2 kilowatt/hours of power (4 x 900 watt/hrs each). Even if all of that energy could be magically transferred into a PIP with 100% efficiency, it would only provide about a 70% charge. Based on this requirement, at least 8 to 10 batteries would be required.

Probably the least efficient way to transfer that energy would be to drive a 12-125V inverter, then pass it through the charge cable into the Prius charging inverter. Even if each of the components were 90% efficient, the combined losses from all components could amount to at least 50% of the power being lost. Based on this, the number of batteries required would double to at least 20. To charge such a battery bank, a fairly large solar or wind-power array would be required, costing many thousands of dollars.

So even though it might be technically feasible to charge a Prius from a 12 volt source, the costs of such a setup would be vastly out of proportion to the intended purpose.