Car fully charged but won't start

I seem to recall someone claiming that it was 10 amps (at 12 volts) briefly needed to get the contactors to close. I wouldn't be surprised if it were a little more or less, though.

LeftieBiker said:

I seem to recall someone claiming that it was 10 amps (at 12 volts) briefly needed to get the contactors to close. I wouldn't be surprised if it were a little more or less, though.

Click to expand...

Well, sounds like my calling then :lol: I'll create a separate topic for it though to avoid steering this one off track. Thanks for checking! :mrgreen:

Sorry about the long post--I was tired and did not proofread/edit it before posting. I wanted to make it clear that the car would not go into READY mode until I cleared a bunch of error codes. I should try to post a photo of the error code listing to show all of the errors that can be caused by a weak 12V battery. I was able to jump start the 2011 and 2015 when their OEM batteries failed and then later clear codes when I replaced the batteries, but the 2019 would not move until I cleared a bunch of codes while the jumper cables were still attached. I know I jump started the 2011 with some 14 AWG test leads I had in my office vehicle, but never tried to measure the current.

And I once used what I think were 18 gauge leads...and they melted their insulation.

GerryAZ said:

Sorry about the long post--I was tired and did not proofread/edit it before posting. I wanted to make it clear that the car would not go into READY mode until I cleared a bunch of error codes. I should try to post a photo of the error code listing to show all of the errors that can be caused by a weak 12V battery. I was able to jump start the 2011 and 2015 when their OEM batteries failed and then later clear codes when I replaced the batteries, but the 2019 would not move until I cleared a bunch of codes while the jumper cables were still attached. I know I jump started the 2011 with some 14 AWG test leads I had in my office vehicle, but never tried to measure the current.

Click to expand...

It sounds like the Gen 2 handles a failed 12 volt battery much differently than the Gen 1. I have jump-start a many Gen 1 (with my Gen 1) before and usually once you get the computer booted up and the main battery online, everything is good (minus the bad 12 volt battery of course).

Now, I have swapped out both my wife and my own Gen 2 leaf with 12 volt lithium batteries, so the Leaf(s) were only without 12 volt power for maybe the 30 minutes it took to disconnect everything and wire up the new battery. They both started back up without any issues and I did find the under-voltage code in both of them, cleared it out, etc. I guess I never tried to drive them right after the battery swap, so that might be why I never ran into this issue like you had?

I wonder though if a weak 12 volt battery would cause a lot more codes and issues than just disconnecting the power completely does, that might be the difference as well?

GerryAZ said:

Sorry about the long post--I was tired and did not proofread/edit it before posting.

Click to expand...

No worries, I was being a bit pendantic anyways.

I remember, back in the mid Nineties, being asked to break up my salon posts. I was Irked, because I knew paragraphing and it wasn't required. Ten years later, I was asking other people to do the same.

I find that the white spaces make it so much easier to scan posts quickly, it's not even a grammatical thing...

Yes, indeed. The rules of syntax weren't written on LED or CRT screens.

I've had two random "won't shift into drive" incidents in the last few months in my 2018 gen 2 Leaf. The exact symptoms were different each time, and both times got it going again after fiddling with it for a while. Nissan dealer in Bristol couldn't find anything wrong.

I got the 12v battery tested by the AA and he said it needed replacing, which was good news as it gives me hope that it was the root cause. All fine so far since the 12v battery was replaced, fingers crossed it stays that way.

Seems like the 12v battery really is the Achilles heel of the Leaf....

You may want to get into the habit - as have I - of triggering the front wipers once or twice per trip. Especially short trips. Doing so raises the charging voltage in the 12 volt system to 14.4 - 14.6 volts, for a minute or so. I once measured the 12 volt battery rest voltage in my 2018 SL at 12.25 volts. It was often around 12.4 volts.