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12 volt battery

Posted: Fri Feb 04, 2022 5:38 pm
by Mathieu
Hi,

With a Honda e, is the 12-volt battery also charged when the high-voltage battery is being charged?

Thanks in advance!
Mathieu

Re: 12 volt battery

Posted: Fri Feb 04, 2022 6:11 pm
by Reuben80
I don't think so. The 12V battery charges when the car is in the ready to drive mode. (when you push the start and brake pedal)

Re: 12 volt battery

Posted: Fri Feb 04, 2022 6:25 pm
by Keawon
Hi, it does.
But only when the car charges and it stops when the car reach set limit. In other words doesnt charge 12v battery by just staying connected.

Re: 12 volt battery

Posted: Fri Feb 04, 2022 6:43 pm
by londiniumperson
I can confirm that It appears to charge when it decides to, but never if you're in accessory mode though.

Re: 12 volt battery

Posted: Fri Feb 04, 2022 7:11 pm
by miura88
The 12 volt battery is charging and maintain its charge when the safety belt is connected.

Re: 12 volt battery

Posted: Fri Feb 04, 2022 9:15 pm
by ZoeDave
It's not exactly the greenest idea, but might an option be to, if you are not going to be driving for a while, keep the car plugged in and set to 80% max charge. Then, every few days or so you could set a 30 minute pre-heating/cooling cycle so the charging circuit turns back on?

Re: 12 volt battery

Posted: Sat Feb 05, 2022 7:59 pm
by londiniumperson
ZoeDave wrote: Fri Feb 04, 2022 9:15 pm It's not exactly the greenest idea, but might an option be to, if you are not going to be driving for a while, keep the car plugged in and set to 80% max charge. Then, every few days or so you could set a 30 minute pre-heating/cooling cycle so the charging circuit turns back on?
No need to do this because the car will top up the battery as it sees fit, people on here have left theirs weeks on end without issue.
It's only a problem if you leave the car in accessory mode and don't have the seat belt engaged. Please don't ask how I know :roll:

Re: 12 volt battery

Posted: Sat Feb 05, 2022 11:04 pm
by milligoon
Didn't touch my car for three weeks over xmas, not plugged in charge % was the same at the end as the start, didn't have any issues with 12v battery either, I didn't bother using the app as after a couple of days it had put itself into sleep mode.

At home I don't overly worry as I park near enough to my garage for my ctek charger to reach should my 12v battery let me down.

Now I've posted this it'll be flat as a flat thing tomorrow no doubt :-)

Re: 12 volt battery

Posted: Mon Feb 07, 2022 3:31 pm
by keithr
See this post in the 'Charging of 12V Battery' discussion.

Re: 12 volt battery

Posted: Wed Feb 09, 2022 7:02 pm
by ZoeDave
londiniumperson wrote: Sat Feb 05, 2022 7:59 pm
ZoeDave wrote: Fri Feb 04, 2022 9:15 pm It's not exactly the greenest idea, but might an option be to, if you are not going to be driving for a while, keep the car plugged in and set to 80% max charge. Then, every few days or so you could set a 30 minute pre-heating/cooling cycle so the charging circuit turns back on?
No need to do this because the car will top up the battery as it sees fit, people on here have left theirs weeks on end without issue.
It's only a problem if you leave the car in accessory mode and don't have the seat belt engaged. Please don't ask how I know :roll:
Thank you, and no, I won't ask, but I can imagine it involves something so obvious to Honda that nobody else even thought it would be necessary! If the pandemic subsides enough to allow me to visit Japan again it's good to know that my 12V system won't be secretly plotting it's demise while I'm away.