LeftieBiker
Moderator
Posts: 18707
Joined: Wed May 22, 2013 3:17 am
Delivery Date: 30 Apr 2018
Location: Upstate New York, US

Re: Keep a dying 12V battery going as long as possible

jlv wrote: Tue Jan 25, 2022 8:02 am This makes sense as long as you are talking about doing this only while you wait for the replacement 12V battery (presumably 51R AGM) that you ordered to arrive, and it's not something you are suggesting people do all the time.
If this is stressing the battery enough to make a difference, then it makes sense to do it with a healthy battery - at least in Winter, when the seat heaters are often left On, and the HVAC blower is often set higher. In Summer, with fewer accessories left on, then just turning off the headlights before shutting the car off should suffice - if the battery is healthy.
Brilliant Silver 2021 Leaf SV40 W/ Pro Pilot & Protection
2009 Vectrix VX-1 W/18 Leaf modules, & 2 lithium E-bicycles.
BAFX OBDII Dongle
PLEASE don't PM me with Leaf questions. Just post in the topic that seems most appropriate.
nlspace
Posts: 658
Joined: Mon Jun 05, 2017 10:21 pm
Delivery Date: 06 Jun 2017

Re: Keep a dying 12V battery going as long as possible

If her 2018 battery is really low capacity, then it might not complete a full 20 hr capacity test. But it would be interesting to hear how degraded it is.

FLA battery failures are really common these days with fewer trips and miles driven. Just last night i helped a neighbor with a jump start for this truck; he thought his alternator was bad, but it was putting out 68Amps into his weak 2 yr old battery. Sitting around without being driven or kept fully charged with a trickle charger, is a recipe for a dying 12V battery.
User avatar
knightmb
Forum Supporter
Posts: 1550
Joined: Mon Jan 12, 2015 7:41 pm
Delivery Date: 26 Feb 2021
Leaf Number: 306291
Location: Franklin, TN

Re: Keep a dying 12V battery going as long as possible

nlspace wrote: Tue Jan 25, 2022 1:33 pm If her 2018 battery is really low capacity, then it might not complete a full 20 hr capacity test. But it would be interesting to hear how degraded it is.

FLA battery failures are really common these days with fewer trips and miles driven. Just last night i helped a neighbor with a jump start for this truck; he thought his alternator was bad, but it was putting out 68Amps into his weak 2 yr old battery. Sitting around without being driven or kept fully charged with a trickle charger, is a recipe for a dying 12V battery.
When the auto store does it's load test, the battery voltage will sag all the way down to 9V but it produces enough power in that short time that in theory, it would start a car according to them. Capacity wise, could you keep cranking on the battery if the car didn't start on the first or second try, probably not. I have tried to do a 20 hour test on it, it never makes it. Basically, it scores around 8AH of capacity, which is way below what the new battery rating gets (I don't remember if it was 31AH or 44AH for the OEM battery). I'm also running my test indoors where it's nice and warm, not freezing outside, so that probably offsets my numbers a little as well. I still keep the battery though, just in case it's needed for temporary service. :)
2020 Leaf SL Plus - (Manufacture Date March 2020)
2018 Leaf SL - (Manufacture Date February 2018)
2013 Leaf SV - (8 faithful years of service before trade in at 75,679 miles LeafSpy-Data)
Timekoin - The World's Most Energy Efficient Encrypted Digital Currency
gcrouse
Posts: 116
Joined: Sat Oct 30, 2021 11:51 am
Delivery Date: 03 Apr 2017

Re: Keep a dying 12V battery going as long as possible

I've still got the original 12v battery in my 2016 Leaf, should i be expecting it to start to die this year? Would it be worth asking the dealer to check it in April when I get my battery pack report?
User avatar
jlv
Moderator
Posts: 1997
Joined: Thu Apr 24, 2014 6:08 pm
Delivery Date: 30 Apr 2014
Leaf Number: 424487
Location: Massachusetts

Re: Keep a dying 12V battery going as long as possible

LeftieBiker wrote: Tue Jan 25, 2022 1:29 pm If this is stressing the battery enough to make a difference, then it makes sense to do it with a healthy battery
Sure. LOL.
ICE free since '18 / over 126K 100% BEV miles since '14
LEAF 2013 SL (mfg 12/13, leased 4/14, bought 5/17, sold 11/18, 34K mi, AHr 58, SOH 87%)
Tesla S 75D (3/17, 52K mi, repaired! :D)
Tesla X 100D (12/18, 40K mi)
8.9kW Solar PV and 2x Powerwall
LeftieBiker
Moderator
Posts: 18707
Joined: Wed May 22, 2013 3:17 am
Delivery Date: 30 Apr 2018
Location: Upstate New York, US

Re: Keep a dying 12V battery going as long as possible

gcrouse wrote: Wed Jan 26, 2022 8:12 am I've still got the original 12v battery in my 2016 Leaf, should i be expecting it to start to die this year? Would it be worth asking the dealer to check it in April when I get my battery pack report?
5 years old is a good time to replace the 12 volt battery. You've gotten your money's worth from it, and the consequences of having it fail while driving, or when you have to have the car start for an important trip, outweigh any advantage from not replacing it. If you get a name brand AGM replacement, you will likely never have to do this again.
Brilliant Silver 2021 Leaf SV40 W/ Pro Pilot & Protection
2009 Vectrix VX-1 W/18 Leaf modules, & 2 lithium E-bicycles.
BAFX OBDII Dongle
PLEASE don't PM me with Leaf questions. Just post in the topic that seems most appropriate.

Return to “Batteries & Charging”