Which battery dies first when leaving the car on?

[rumpole]

The DC-DC converter keeps the 12V battery charged as long as the car is ON, as folks have commented. Remember that the solar panel does, as well, also as long as the car is ON.

You can actually pull extra current out of the DC-DC to run an inverter to use as emergency power, too. This was done after Hurricane Sandy a while back. See http://www.mynissanleaf.com/viewtopic.php?f=27&t=10475&start=20#p240384" onclick="window.open(this.href);return false;

If the DC-DC weren't charging the 12V, this wouldn't work, but it does.

 

[DarkStar]

Remember that the solar panel does, as well, also as long as the car is ON.

The solar panel is connected directly to the battery via a 5 amp fuse. It will charge the battery while the car is off.

 

[TimLee]

The DC-DC converter keeps the 12V battery charged as long as the car is ON, as folks have commented. Remember that the solar panel does, as well, also as long as the car is ON.

You can actually pull extra current out of the DC-DC to run an inverter to use as emergency power, too. This was done after Hurricane Sandy a while back. See http://www.mynissanleaf.com/viewtopic.php?f=27&t=10475&start=20#p240384" onclick="window.open(this.href);return false;

If the DC-DC weren't charging the 12V, this wouldn't work, but it does.

DC-DC converter functions differently in ON than it does in Ready mode.
If you use ON instead of Ready you are sagging the 12V charge level more than if you use Ready mode.

 

[voganni]

The time my 12v battery was almost dead, 5 volts or so, the brakes felt odd. More pedal travel than normal. The car also would not power up, dash display flashing, and the "T/M system failure, visit dealer" warning. The brakes were my first clue that something was wrong, as I pressed the brake before I hit the power button.

I'm thinking of installing a big knife switch in the negative battery cable, I've had to disconnect it so many times! :lol:

 

[TomT]

Do a search and you'll find a thread on installing a wing nut to make disconnecting the battery easy... http://www.mynissanleaf.com/viewtopic.php?f=38&t=3231" onclick="window.open(this.href);return false;

I'm thinking of installing a big knife switch in the negative battery cable, I've had to disconnect it so many times! :lol:

 

[voganni]

I don't think I'll go to the extreme of a wing nut (or knife switch, seriously). But I do carry a 13mm battery post wrench in the console, and will have my battery tender and digital voltmeter along when I do my planned road trip. Ah, the carefree life of the Leaf owner........

If/when I get to Seattle in my Leaf, I'll stop in at Campbell-Nelson Nissan and see if they know anything about my issue. They sell a lot of Leafs. Also have a DC quick charge station!

 

[Nubo]

I took my 2011 SL in for a 2 ½ year service and asked the dealer to check the battery. They came back and said the 12v needed a charge as it was only 1/2 charged. They said I was not charging or using the car enough to completely charge both batteries. I told them that my commute to work is 44 miles round trip 5 days a week and I charge to 80% every night. The service managers asked why was I doing that and recommended I charge to 100% once in a while.

In the fine tradition of Service Managers everywhere.... When faced with a potentially time-consuming troubleshooting task, blow smoke up the customer's ass.

 

[JohnP]

I really wish they would just say they don't know. I get a ton more information from this blog than talking to the dealership that just wants me to go away.