rashford
Posts: 3
Joined: Mon Aug 18, 2014 12:19 pm
Delivery Date: 08 Aug 2014
Leaf Number: 307535

Re: LEAF's 12V battery behaviors - and why they go bad

Mon May 22, 2017 11:31 am

My 2015 SV has had many 12v issues and only since the telematics upgrade. Dealer says there is no issue and now wants to charge for loaner car. Nissan has a problem and is not owning it!!!! :x Warning lights come on and the 12v battery dies within a few days. Sounds like before I sell it, I will disable the "carwings" to avoid the problem.

arnis
Posts: 753
Joined: Sat Jan 23, 2016 3:21 pm
Delivery Date: 23 Jul 2014
Leaf Number: 015896
Location: Estonia, Europe

Re: LEAF's 12V battery behaviors - and why they go bad

Tue May 23, 2017 9:08 am

Realistic thing that can happen due to Telematics module is that it doesn't allow vehicle to fall asleep.
This can be diagnosed. End of story.
Short range EVs <30kWh -- Medium range: 30-60kWh -- Long range: >60kWh
Charging: Trickle <3kW -- Normal 3-22kW -- Fast 50-100kW -- Supercharging >100kW

Scaramanga
Posts: 111
Joined: Fri Apr 28, 2017 9:31 pm
Delivery Date: 23 Dec 2016
Leaf Number: 308884
Location: Tacoma, WA

Re: LEAF's 12V battery behaviors - and why they go bad

Tue May 23, 2017 11:08 pm

Where does the telematics board live, could someone take it out to prove this? How old does a battery get before it starts to do this? Like my '16 SL has 3G telematics and a solar cell and works great. Is this an S or SV only issue?
2016 SL Premium - Gunmetal Grey, built 2/2016
2014 S w/ QC - Cayenne Red, built 1/2014
EVSE: ChargePoint 25 32A Plug-In w/ 18' Cord
ELM 327 / LeafSpy Pro
'06 Sentra Compact Spare / Jack
Renault Tow Hook

2016 Murano SL AWD
VW / Audi / Volvo ex-aficionado

cwerdna
Gold Member
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Joined: Fri Jun 03, 2011 4:31 pm
Delivery Date: 28 Jul 2013
Location: SF Bay Area, CA

Re: LEAF's 12V battery behaviors - and why they go bad

Tue May 23, 2017 11:31 pm

Scaramanga wrote:Where does the telematics board live, could someone take it out to prove this?
...
Is this an S or SV only issue?

It is behind the glove box. It looks like viewtopic.php?p=148255#p148255.

S has no TCU. And, SL is the only one w/the solar cell.

For those with '11 to '15 Leafs, IIRC, there are at least 3 different part numbers (and thus 3 different parts) for the upgraded TCU and there might be only 1 appropriate 1 for a given vehicle.

'13 blue Leaf SV w/premium package (owned)
'13 blue Leaf SV w/QC + LED & premium packages (lease over, car returned)
'06 Prius

greengate
Gold Member
Posts: 537
Joined: Mon Feb 04, 2013 9:31 pm
Delivery Date: 04 Feb 2013
Location: Wilmette, IL

Re: LEAF's 12V battery behaviors - and why they go bad

Sun Jun 25, 2017 7:34 pm

Thanks to everyone for the thoughtful comments.

The shop did run a battery load test and found it to be completely dead and after 4.5 years of use, I do not feel that the dealer had any fault in the battery having failed..like someone walking into a hospital at the age of 90 to have a splinter removed from his hand and while waiting has a fatal heart attack.

Life happens..life disappears....but yes, when the 12 V goes, you have limited control over the vehicle..hand brake and steering wheel only and that's with difficulty especially in moving traffic.

I don't have a suggested remedy for this situation..how does one even know when the 12 volt is about to die, but if it exists, this information/warning should be programed into the system.

Wonder how Tesla has approached this issue.

arnis
Posts: 753
Joined: Sat Jan 23, 2016 3:21 pm
Delivery Date: 23 Jul 2014
Leaf Number: 015896
Location: Estonia, Europe

Re: LEAF's 12V battery behaviors - and why they go bad

Tue Jun 27, 2017 12:56 pm

Tesla also has no smart 12V monitoring. Same failures happen like with Leaf.
BMW uses extremely smart, self-sustaining module right on the negative terminal of the battery
(powered directly from battery) starting from 2005. And some other premium brands as well.

It reports to driver : a) battery has been discharged slightly b) battery has been discharged deeply
c) yellow warning, battery degraded, replace recommended soon d) red warning, battery is no good
With A/B it recommends to to charge battery (or drive ICE vehicle for longer).
12V battery SOC is monitored like Leaf monitors HV battery. 24/7. Until voltage drops to near zero.
It recalculates capacity according to Ah consumed, voltage, temperature, etc.
BMW keeps battery charged at 70-80% state of charge. This way 12V AGM batteries usually last 4-8 years.
But they all die eventually.

So Nissan and Tesla could all implement this basic tech. But they don't. And I don't know why.
For ICE vehicle it adds like 300-400€ of cost. But for EV, 12V converter is already capable doing all that is required.

Examples of messages:
Image
Some vehicle functions are not enabled until battery is adequately charged during driving.
Image
This one explains that there was abnormal draw during resting period.

For example, during very long parking periods (months) when BMW owner comes back to vehicle he/she might
be surprised that doors do not open. Well this BMS was counting all the amp-hours that have been used up during sleep
and right before it is too late it switches off those last consumers, like clock settings, telematics, alarm and central locking.
But opening the door manually with physical key will wake up the vehicle and will allow that last cold start.
With the price of slight inconvenience (clock, seat memory, radio memory etc) and not able to use many power hungry
electronics for limited period (like half an hour), owner doesn't have to call a friend for a jump.
Short range EVs <30kWh -- Medium range: 30-60kWh -- Long range: >60kWh
Charging: Trickle <3kW -- Normal 3-22kW -- Fast 50-100kW -- Supercharging >100kW

User avatar
Randy
Moderator
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Leaf Number: 0191
Location: San Diego, CA

Re: LEAF's 12V battery behaviors - and why they go bad

Tue Jun 27, 2017 1:19 pm

Don't know what to tell you, Arnis, but my 2013 Tesla Model S gave me a message on the screen that said my 12 volt battery needed to be replaced. I scheduled it with the local service center, and they sent the mobile repair guy (a "ranger") out to do the work under warranty...Clean and simple...

cwerdna
Gold Member
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Joined: Fri Jun 03, 2011 4:31 pm
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Location: SF Bay Area, CA

Re: LEAF's 12V battery behaviors - and why they go bad

Wed Jun 28, 2017 12:55 am

Re BMW, I've seen a # of folks have bad 12 volt batteries on the i3. And, for whatever reason, the driver is not supposed to jump start it! :roll: :? So, that usually means a trip to the "spa" on a flatbed truck.

For others who get into that state, I'm not clear if they have some malfunction. I've seen people post pics of messages like "Battery discharging while stopped. Start engine. If fault persists, consult service center."

'13 blue Leaf SV w/premium package (owned)
'13 blue Leaf SV w/QC + LED & premium packages (lease over, car returned)
'06 Prius

brenton
Posts: 7
Joined: Sun Sep 17, 2017 3:08 pm
Delivery Date: 17 Aug 2015
Leaf Number: 404682

Re: LEAF's 12V battery behaviors - and why they go bad

Sun Sep 17, 2017 3:16 pm

Following rule 3 in the "read this first" (viewtopic.php?f=6&t=2499) thread, I have a question on the topic of 12V battery behavior.

First, what actually charges the 12V battery? Is it one single thing, (like an alternator) or are there multiple things that could possibly charge it?

Secondly, under what conditions will the 12V battery charge? Does it charge while trickle charging, L2, Chademo? Does it charge while driving?

Last, is it possible that too many short trips could mean the battery doesn't ever get back to full? I had a little Yamaha scooter that had this problem.

You can probably guess that I'm asking all this because my Leaf is having 12V battery problems. It's a recurring problem every 3 weeks or so, and it's a brand new, OEM battery, so I'm just trying to educate myself on how the 12V system in the Leaf works generally.

Jedlacks
Posts: 149
Joined: Sun Dec 14, 2014 12:10 pm
Delivery Date: 29 May 2016
Location: Kennesaw, GA

Re: LEAF's 12V battery behaviors - and why they go bad

Sun Sep 17, 2017 3:58 pm

I'll tell you what I did from information gathered from this thread, and from a PM that I exchanged with a member.

I bought a BatteryMINDer 1500 along with the ring terminal assembly. I attached the terminal permanently to the 12V battery and drilled a small hole beside the J1772 plug in the charge port. Then I filled the battery cells with distilled water. All this is less than half the price of a new battery.

Once a week I plug the batteryMINDer in and let it run overnight. Actually, I usually do it as often as I care to as it desulphates and maintains the battery and brings it up to new/steady state of charge. When I pull into the garage I pop the charge port and I have a choice of plugging in either cables. There are a few threads about the J1772 being always plugged in and not charging will harm the 12V, but that does not bother me because the other cable is plugged in. Additionally, when I have both plugged in and my timer starts in the wee hours, the batteryMINDer gets warm. That does not bother me because it does not appear to do any harm.

I was putting a new battery in our Mercedes every two or so years. Now I share the same device with the Benz, and it is already a year beyond the "scheduled" trip by Mercedes Benz repair service.
2015 SV QC/LED
Juicebox 40A

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