Motarra wrote:I cannot seem to find what should be a simple answer to a simple question. 12v battery on 2014 Leaf S is dead. I reviewed Nissan's directions for jump starting the car which are pretty straightforward. So now it's "running" and drivable.
1 - Is the 12v battery being charged even when the Leaf is left on and in park in the garage? Is this an adequate (though probably inefficient) method to recharge the 12v battery? Its sitting now with all other systems off (AC, lights, radio).
2 - In order to test and then charge up the 12v battery with a regular 12v car battery charger what are the proper connections? positive/positive and negative/engine block like on a ICE? Or as I have read on various forums is it better to disconnect the battery from the car and connect it directly to the 12v charger.
Calling Nissan Leaf support was not too helpful.
Waiting to hear back from a tech at my dealer since the service advisor did't know.
My main concern is avoiding any damage to the car. I'm probably being overly cautious.
Thanks for your input.
1. If you are trying to charge the 12V battery in car you want the car on, and run the windshield wipers on the slowest delay non stop. While running the wipers the inverter puts out much higher voltage and will charge the 12V quicker that way. You might have to spray some water on the wipers/glass first or use the wiper fluid occasionally to keep from shredding the wipers.
It may sound counter intuitive but the Leaf assumes if the wipers are on you are likely using the lights and radio and such and it pumps higher voltage into the 12V bus to offset the expected drain and it will keep that voltage high for several minutes after the wipers cut off to help the 12v battery recover. So if you run the wipers on the slowest delay but keep the radio, lights, etc off it will charge quicker (assuming you are in Ready mode and it is running off the high voltage pack and not draining the 12V further).
2. You will be better off to some extent removing the 12V battery from the car to charge it but I'd just grab a CTEK 3.3 or 4.3 amp and plug it in without removing the 12v from the car. In a pinch a battery minder or lesser quality dumb charger will work for bulk charging but I prefer using a desulfating smart charger like the CTEK.
Oh and there is no Engine block. Ingineer advises "that the negative cable should not be connected directly to the battery. He suggested clamping to the big cable that connects to the DC/DC converter, but any grounded place on the car away from the battery should work fine."
Silly me, I've used the negative straight on the battery. I do however make sure the car isn't plugged into both an EVSE and a 12v battery charger at the same time. I either charge the HV battery pack or charge the 12v, I don't try to mix the two.