I have a few questions about the 12v and large battery and how they charge. I plan on adding some auxiliary lighting around it for camping and stuff.

If I were to completely drain the 12v battery without the keys in the ignition overnight, would I be able to start the car by pushing the jumpstart button and waiting, or would it drain the big battery pack as well?

If the 12v battery does not need cranking amps to start the engine, couldn't I use a deep cycle battery instead, so I can discharge the battery frequently without damaging it?

I've seen people reference to the jumpstart button under the driver side kick panel. All I see is a button behind the small door to the left of my steering wheel, is that it?

Bonus question: Is it possible to change the duration the headlights stay on when initially unlocking the car with the remote?

 

You would only drain the 12 volt battery, but if the 12 volt battery is too dead, you cannot simply do a key-on to charge it from the 330 volt battery.

Yes, but even a deep cycle battery should only be discharged to 50% (about 12 volts).

Dunno

Dunno

 

My impression is that the 12V battery needs only enough power to close a relay that enables the traction battery to start the engine. Which isn't much, and is why FEH owners sometimes run into accessory problems before realizing the 12V battery is weak. You don't get the slow starts like in a non-hybrid with a weak battery.

Once in "run", the engine will cycle on and off as needed to keep the traction battery charged, and I would assume the 12V battery also.

Given this, I don't see why you couldn't use a deep cycle battery.

As for the Jump start button, here's more info:
https://www.greenhybrid.com/forums/f...-big-pac-2987/

This may only be on the first generation. I certainly don't have any such access panel on my '09 FEH, and I don't recall seeing mention of this in the owner manual. I've recently spent quite a bit of time working on wiring behind and near the kick panel, and have not seen any such button.

 

This is true. My brake motor sounded like a sick cow and I only realized later that it meant the battery was weak. I left my parking lights on for an hour and when I returned, the battery was so dead it would not start the vehicle. Nothing.

 

I had no problem with the OEM Battery going out to 8 years. But when one cell shorted it didn't have enough to close the relay contacts without a charger attached even when all other cells were good & charged. Note that it's a big relay in the 330Vdc circuit, so you don't have as much reserve as one would think.

 

My daughter borrowed my 2009 FEH after the transmission went out on her car, relegating me to my old farm truck. She called me from 200 miles away to say the Escape wouldn't start, wouldn't turn over, nothing. She had no advance warning whatsoever, but she said that she had gone through drive through and had been sitting close to half an hour eating lunch, reading and charging her iPhone. I had been wondering about how long the 12v battery would last, so the first thing I told her to do was get a new battery. Her boyfriend put in the battery and all is back to normal. None of this is inconsistent with this thread but does support the idea that you won't necessarily have much advance notice. I wish I had my scan gauge on it to see what the battery output was when she was having problem.

 

My Scan Gauge said my battery voltage was down to 10 volts after I left the parking lights on.

 

Did it still start?

John

 

No, see post #4 above.

 

Since you don't have the starter motor that sucks several hundred amps like in more conventional cars, you'd think you'd have more reserves. Yet my inference is that the relay that is pulled in to connect the traction battery to the transaxle and such, is a big enough relay that it needs a lot of punch to pull it in.

In my experience a fully charged battery with one cell shorted won't pull it in. This equates to a battery down to 10.5 to 11.0 volts. Just has to be a big relay to need that kind of punch to pull it in.