Phil, Sorry but I got to correct you there, the Leaf will *charge* the aux battery for a short time after starting the vehicle, whether driving or charging (when contactors are closed, as you write), HOWEVER, as soon as the charge current drops below 10 Amps and on an older battery that is almost instantly, the DC/DC stops charging it and switches to a maintenance voltage which will essentially NOT charge the 12V battery any further. If I am not mistaken, the charge voltage is 14V and the maintenance voltage is at or below 13V which means that almost no current is absorbed by the aux battery, which is what you WANT for a fully charged battery, but since an older battery can be almost empty but due to not accepting 10 Amps of current at 14V, it will get 13V and stay essentially empty the whole time, that is why Leaf batteries die early. They never properly get charged, let alone balanced (occasionally overcharged to re-balance the 6 cells) by the car.
On Sat, Aug 1, 2026 at 2:08 PM (-Phil-) via EV <[email protected]> wrote: > > I owned a G1 2011 Leaf. It charged the 12v anytime the contactors were > closed. That means 100% of the time it's charging the main pack. What got > you was leaving it connected, which once charged, it has a high standby draw > keeping the VCU awake because prox is asserted. The best way to store > almost any EV is simply to disconnect the 12v. Most cars will be good for > over a year if you leave the charge at around 60% and disconnect 12v. > > On Sat, Aug 1, 2026 at 11:17 AM Bryce Nesbitt via EV <[email protected]> > wrote: >> >> No, >> the Leaf 12V maintainer is very very stupid, at least in the original >> version. >> It's timer based. >> >> And never leave the vehicle charging for more than a day, as during charging >> it uses more of the 12V battery and does not charge the 12V. I learned that >> the hard way leaving >> a Leaf charging while on vacation for a week. >> >> The little solar panel on the original leaf? Useless. >> >> I have a hack to fix this. >> >> >> On Sat, Aug 1, 2026 at 6:58 AM Darryl McMahon via EV <[email protected]> >> wrote: >>> >>> Interesting. I had battery maintainers (either solar on dash or >>> plug-in) on all my ICE vehicles over the years. Mostly because they >>> typically didn't move for weeks at a time as there was pretty much >>> always an EV of some kind in the driveway to do most of my trips. >>> >>> It didn't occur to me to put one on the Leaf due to the big DC-DC >>> converter from the traction pack that should be maintaining the 12-volt >>> auxiliary. >>> >>> I'm content that the failed 12-volt battery had served its time and I >>> think served past its expected life. >>> >>> As for battery maintainers, I can come up with one of those pretty >>> easily (I sell an intelligent version). I should put one on the current >>> gasser - my SO will love having an electric plug hanging out from the >>> front grill (actually, not so much). Not so unusual around here where >>> we still have a lot of gassers with either battery blankets or block >>> heaters or both to improve chance of engine starts on truly cold days. >>> (Back in my pre-OEM EV days, I carried jumper cables so I could tap the >>> traction pack to jump start frozen gassers on the cold days. Can't do >>> that now on the factory EVs because I can't tap the pack or boost from >>> the auxiliary per the owner's manual. So now I carry one of the tiny >>> jump packs for that purpose.) >>> >>> On 2026-08-01 1:08 a.m., Bryce Nesbitt wrote: >>> >>> > >>> > That's exactly what the leaf does with a flat 12V battery. >>> > Just replace it, and put the new one on a battery maintainer. Under >>> > $200 at Batteries & Bulbs, expect a 3 year lifetime for the 12v >>> > battery, maye 4 with the maintainer. >>> >>> -- >>> Darryl McMahon >>> >>> -- >>> This email has been checked for viruses by Avast antivirus software. >>> www.avast.com >>> _______________________________________________ >>> Address messages to [email protected] >>> No other addresses in TO and CC fields >>> HELP: http://www.evdl.org/help/ >>> OT: If you use an Android device, please read https://keepandroidopen.org/ >> >> _______________________________________________ >> Address messages to [email protected] >> No other addresses in TO and CC fields >> HELP: http://www.evdl.org/help/ >> OT: If you use an Android device, please read https://keepandroidopen.org/ > > _______________________________________________ > Address messages to [email protected] > No other addresses in TO and CC fields > HELP: http://www.evdl.org/help/ > OT: If you use an Android device, please read https://keepandroidopen.org/ _______________________________________________ Address messages to [email protected] No other addresses in TO and CC fields HELP: http://www.evdl.org/help/ OT: If you use an Android device, please read https://keepandroidopen.org/
