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Re: How to Quickly & Simply Charge a Leaf’s Weak 12 Volt Battery

Posted: Thu Dec 17, 2020 3:52 pm
by LeftieBiker
Maybe it's time to put in a hardwired SAE battery lead.

Re: How to Quickly & Simply Charge a Leaf’s Weak 12 Volt Battery

Posted: Thu Dec 17, 2020 4:47 pm
by lorenfb
GerryAZ wrote:
Thu Dec 17, 2020 12:04 pm
The threshold level depends upon the model year, but is less than 10 amperes on 2011 and lower on later models. I have never connected an external charger to any of my LEAFs. I saw sustained charging current of about 80 amperes while driving home from my office after the battery in the 2011 was completely discharged because I left the Bluetooth adapter plugged into the OBDII port and the Android device running Leaf Spy on the passenger seat while parked for 6 days. I used some test leads to "jump start" the Leaf from my office vehicle and drove home without issue.
How did you "see" a charging current of 80 amps? That seems excessive for the small 12V battery used by the Leap.

Re: How to Quickly & Simply Charge a Leaf’s Weak 12 Volt Battery

Posted: Thu Dec 17, 2020 4:52 pm
by GerryAZ
lorenfb wrote:
Thu Dec 17, 2020 4:47 pm
GerryAZ wrote:
Thu Dec 17, 2020 12:04 pm
The threshold level depends upon the model year, but is less than 10 amperes on 2011 and lower on later models. I have never connected an external charger to any of my LEAFs. I saw sustained charging current of about 80 amperes while driving home from my office after the battery in the 2011 was completely discharged because I left the Bluetooth adapter plugged into the OBDII port and the Android device running Leaf Spy on the passenger seat while parked for 6 days. I used some test leads to "jump start" the Leaf from my office vehicle and drove home without issue.
How did you "see" a charging current of 80 amps? That seems excessive for the small 12V battery used by the Leap.
I measured it with a DC clamp-on ammeter when I first jump-started the car. It tapered as the battery charged on the drive home. Charging current into the battery is a function of the source available, state of charge, and internal resistance so when the battery is deeply discharged it can accept high current.

Re: How to Quickly & Simply Charge a Leaf’s Weak 12 Volt Battery

Posted: Thu Dec 17, 2020 5:13 pm
by DaveinOlyWA
lorenfb wrote:
Thu Dec 17, 2020 4:47 pm
GerryAZ wrote:
Thu Dec 17, 2020 12:04 pm
The threshold level depends upon the model year, but is less than 10 amperes on 2011 and lower on later models. I have never connected an external charger to any of my LEAFs. I saw sustained charging current of about 80 amperes while driving home from my office after the battery in the 2011 was completely discharged because I left the Bluetooth adapter plugged into the OBDII port and the Android device running Leaf Spy on the passenger seat while parked for 6 days. I used some test leads to "jump start" the Leaf from my office vehicle and drove home without issue.
How did you "see" a charging current of 80 amps? That seems excessive for the small 12V battery used by the Leap.
Just over a 1000 watts? Not really...

Re: How to Quickly & Simply Charge a Leaf’s Weak 12 Volt Battery

Posted: Thu Dec 17, 2020 6:26 pm
by GerryAZ
Thinking back, I might have had the clamp-on in a position to measure the output of the DC-DC converter instead of only input to the battery--I just remember being surprised at the initial current level. If so, then the actual current into the battery might have started at around 40 amperes before tapering since there could have been 40 amperes of other load with A/C fans, computers, lights, etc.

Re: How to Quickly & Simply Charge a Leaf’s Weak 12 Volt Battery

Posted: Thu Dec 17, 2020 7:31 pm
by lorenfb
GerryAZ wrote:
Thu Dec 17, 2020 6:26 pm
Thinking back, I might have had the clamp-on in a position to measure the output of the DC-DC converter instead of only input to the battery--I just remember being surprised at the initial current level. If so, then the actual current into the battery might have started at around 40 amperes before tapering since there could have been 40 amperes of other load with A/C fans, computers, lights, etc.
Even at 40 amps charging current, that's still excessive. Are you sure you used the correct meter scale?
Maybe you were actually measuring the jumper battery current into the Leaf's battery.

Furthermore, based on your initial statement;
I saw sustained charging current of about 80 amperes while driving home
How were you able to read a clamp-on amp-meter while driving, if it was properly connected directly to one of the battery cables?

Re: How to Quickly & Simply Charge a Leaf’s Weak 12 Volt Battery

Posted: Thu Dec 17, 2020 7:58 pm
by GerryAZ
I connected the clamp on and read it for a few minutes before I started driving because I wanted to make sure the battery was taking a charge so I would not get stranded on the way home. I saw it tapering while the car was still parked and then put the meter away. I used the clamp on again when I got home to verify that the current was down to a level indicating the battery was recharged enough to reliably start the car again. I did end up replacing the battery a month or so later because it was damaged by being deeply discharged, but it still lasted longer than typical OEM batteries in my hot, dry climate (probably because temperatures under the hood of the Leaf are much lower than ICE vehicles).

I guess I should not have used the word sustained in my original comment because it did taper. I will not go back to edit that post because it would make the replies confusing.

Re: How to Quickly & Simply Charge a Leaf’s Weak 12 Volt Battery

Posted: Fri Dec 18, 2020 5:55 am
by Stanton
DaveinOlyWA wrote:
Thu Dec 17, 2020 8:50 am
Stanton wrote:
Thu Dec 17, 2020 7:59 am
I have one of those Antigravity Battery Tracker devices on my 12v...and it shows that the charge level "spikes" to 14v every 15 minutes (or so). You can't expect a (standard) lead acid battery to last in any car, let alone an EV with parasitic drain. Those of you who follow my 12v Lithium thread know that I'm way past 5 years on mine with no issues (and no special treatment).
Interesting. I am guessing this only happens when car is running? How long do these spikes last?
It happens both when the car is on and when it is charging. While these 14v spikes only last a minute or so, the cycle repeats while in either of these modes (so some benefit occurs).