So you get home, turn the car off & the radio stays on for 10 min, which battery is it using? If you then turn the ACC on to continue listening which battery is it? And finally if it's the 12v, how long before it's to dead to "start" the car?

Just currious. I "killed" the battery in my Expedition once listening to the radio wile working outside one weekend. It was on like 2-3 days before starting the truck, a quick jump & it's been fine for 7 years now. Just don't want to risk killing the neccessary battery and not being able to get started.

 

If the key is out, or to ACC it is only the 12v battery providing power for the radio, lights, power windows, etc.

If the key is to "run", weather the engine is running or not, the 330V battery provides power for everything via 330v to 14v step-down converter. The "big" battery will only drain to about ~300v to protect itself, then it automatically shuts itself off, but the radio and headlamps, etc. will continue from the 12v battery.

So as far as I can tell, you can run down the 12v battery, eventually, but you should not be able to run down the 330v battery.

The 330v battery is what starts the car, but the 12v battery is the only battery connected to the ignition key, for obvious shock prevention reasons, so you need the 12v battery to "turn on" the 330v battery.
If your 12v battery is ever "dead" you will need a jump start.
If your 12v battery is very weak, the FEH should still start, as the 12v battery is not ever used to crank the engine.

 

I asked a similar question a while ago.

Check out those replies...

https://www.greenhybrid.com/discuss/...-lights-13911/

 

I am looking at using a 400w inverter plugged up to my lighter to power some lights while camping. If I leave the key in "run" (engine not running)...am I correct to assume the power will be drawn from the big 330v battery? Which will take a long time to run down--I have just two little lights I want to run for a few hours in the evening.

If I start the engine, it will run to keep the big battery charged...but also subject to start running if the cat temp gets too low, right?

Nate

 

I beleive the smart junction box turns off accessory power after 15 min so it would be hard to do that.

 

I ran the battery down last week by leaving the 4-way flashers on. These must not be on the smart junction box for safety reasons.

The car would not start, and gave no indication why. I jump started the car. It was obvious there was little current draw from the host vehicle. When the jump connection was made, the start was immediate and fully powered by the traction battery. I expect the host battery could have been much smaller. A 12V NiCad pack would have done the job.

 

Sounds like your findings are consistent with this...

 

400 watts will require at least a 30 amp circuit and 30 amp fuse with at least 10 gauge wire. Your cigarette lighter does not have this. Your cigarette lighter (both if you have two ) is rated for 10 amps. Even if you put in a larger fuse in the fuse box, you will melt wires if you try to use 400 watts. So run your own wires of 10 gauge if you wish to use a 400 watt inverter.

From the HV battery with key to "run":
400 watts will go for 1 hour from 4 or 5 minutes of engine on time.
200 watts will go for 2 hours from 4 or 5 minutes of engine on time.

Do not leave the car "started". If you can, start the car and let it charge till it quits on it's own. Then turn the key off, and back to run without starting. Then manually re-start the car based on the above data.
EDIT: Run the car till it quits and then move the gear to Neutral. In Neutral, the engine cannot restart, but keeps all the computers ( Smart Juction Boxes ) active. I forgot, that if you turn the key off, then back to run without a start, it will draw power from the HV battery for a while ( like 10 or 15 min ) then 'time-out'. Then it draws out of the 12v battery. Keeping the car in neutral keeps the car from timimg out. ( place the parking brake on and put chokes under your tires )
I have done this 3 or 4 times. Works like a charm!
Good Luck! -John