Toyota-Leviton Charger Install

It's a very interesting question, but I don't think your test proves that the EVSE serves as a 12V "battery tender." For one thing, once charging competes, it appears that everything shuts off, and if so, any 12V charging would stop. So if, for example, you go on a trip and leave your PiP plugged in, I'm not convinced that the 12V battery would be charged. I would love to learn if this were true, it would be fantastic!

 

Here's the math:
4 watts x 730 hours / 1,000 = 2.92 kWh/month.

At ten cents per kWh, leaving the charger always connected will cost 29.2 cents per month. Of course, you plug it in 3 hours per day anyway, so the incremental cost would be closer to 25 cents per month.

 

The 12v auxiliary battery will recharge by the main DC-DC converter while running. It is not another way.

 

I don't understand if you're answering my question. Does the HV battery maintain the 12V battery charge when the EVSE is plugged in? I know it charges the 12v when the car is in Ready mode, but I don't know what happens during charging.

 

Except I pay 25 cents per kwh.

 

I suspect that people that quote a very low rate don't add up all the lines that are then multiplied by the kwh used (ie. taxes, renewable energy, fuel surcharge, etc.)

 

Rebound

My later checking confirms what you said. When the EVSE charging stops any charging of the 12v battery stops. Then I plugged in my battery tender and when it said my 12v battery was full, it tested at 12.6v! There definitely is some charging of the 12v battery with the EVSE, but not enough to trash the Battery Tender. To be fair, there was a dome light and perhaps some other draw on the battery at the time which would have depressed the reading.

Allan

 

It'd be interesting to see the electric rate schedule for your area and to know your monthly usage vs. whatever baseline you're allocated.

Possibly, but here are two really cheap areas:
2011 Rates
Seattle City Light: Electric Rates & Provisions