It's safer to use the terminals under the hood because a spark there would not hurt anything (Unless you have a gasoline leak up there).
The battery is vented under the car so there "shouldn't" be any hydrogen in the battery compartment. However any spark can set off hydrogen and it is a fairly closed off space.
Interesting info here, strange too - thanks.
This just about puts everything I ever knew about a standard auto battery charging principles in the trash can.
These hybrids really are different.
I have a Schumacher Digital battery charger with lots of modes and readouts.
I just connected it to the under-hood positive and negative posts.
The initial readouts were at 63% and 12.4 volts, and we just got back from going to dinner.
I have it charging right now.
I looked at the Engineering Mode the other day and it was at 13.4 with the ICE running and charging.
I think I'll top this battery up more often. Maybe the ICE startup charging will be easier now with the 12v battery fully charged.
These are becoming more like the Plug-in Energi models everyday, with a bigger trunk!
You know, this really shouldn't be this way, a car that can't properly charge it's 12v battery, then have a tiny amp load battery installed as OEM is somewhat short-sighted.
I am starting to see why the OEM battery is so small, the HVB system that has to charge it is under-engineered.
Who in the world would buy this car if they were told they had to buy a battery charger and do this themselves every 6 months, or have it charged at every Dealer service.
Of course, in my case, it could have been be topped off perfectly, I've been at the Dealer every month since I've owned it.
I should have been having them charge it as standard procedure, like the air pressure in my tires.
Ford, you've got to be kidding... This is nuts.
EDIT: My battery charger just went to 100% and 12.9v. That's not very good.
I know I've posted this graphic elsewhere in the Forum but this Thread seems like a logical place to insert again.
Edited by GrySql, 07 September 2013 - 07:50 PM.