DaveinOlyWA
Gold Member
Posts: 11793
Joined: Sat Apr 24, 2010 7:43 pm
Delivery Date: 10 Nov 2016
Leaf Number: 314199
Location: Olympia, WA
Contact: Website

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

Sun Apr 02, 2017 11:59 am

2 lbs? nice! the terminals are almost as big as the battery itself
2011 SL; 44,598 miles. 2013 S; 44,840 miles. 2016 S30; 18,297 miles. 363 GIDs, Ahr 82.34, Hx; 100.00% kwh 28.1 QCs 165, L2's 190
My Blog; http://daveinolywa.blogspot.com" onclick="window.open(this.href);return false;

VitaminJ
Posts: 357
Joined: Tue Jan 03, 2017 11:46 am
Delivery Date: 07 Jan 2017
Leaf Number: 415775
Location: Morrison, CO
Contact: YouTube

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

Mon Apr 17, 2017 11:40 am

Had my first issue with the tiny 5Ah battery this weekend. The car was driven probably 150 miles on Friday and then parked at about 30% not plugged in. I went to drive it the next day maybe 14 hours later and got the spazzing dash lights, relay clicking, etc that accompany a low 12v battery.

Luckily the Tattu LifePO4 DOES have low-voltage protection, and simply turned itself off when the voltage was too low to protect itself, after charging for an hour or so all is back to normal.

I think the cooling fan and pump ran for a long time after parking it Friday (constant AC use, highway driving, and quick charging) and drained the 12v. For others less risk-adverse I would suggest at least a 10Ah LifePO4 battery, but I am still happy with the 5Ah model especially now that I know it will protect itself.
2013 Ocean Blue SV w/ QC and LED
- +0.2 mi/kwh Aeromods
- Leaf Box
- 2lb 5Ah LiFe 12v battery

jjeff
Posts: 1363
Joined: Wed Jan 13, 2016 9:10 am
Delivery Date: 13 Jul 2014
Leaf Number: 422121
Location: MSP MN

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

Mon Apr 17, 2017 12:22 pm

^^^ I think your right on what might have happened, 5ah isn't much capacity for running a large fan. As a backup should this happen when out and about, I might suggest a smallish portable 12v Li battery jumper. I always carry one in the back of my Leaf for just such occasions. It came with a 12v cigarette lighter adapter or small jumper cables, oh and it also has a 5v USB output for charging portable things that use USB.
All in all for the <$30 I paid for it on sale, I believe $39 regular price, I hope it's worth it, if I ever ran into a weak 12v battery :)
I bought mine at a big box hardware type of store(Menards) but I believe Amazon and other places sell similar models.
2012 SL purchased used 2/'16
2013 S w/QC purchased new
Juicebox Premium 60a L1/L2 EVSE, Ebusbar 16a L1/L2 EVSE
'12 EVSEupgrade'd 20a L1/L2 EVSE, '13 EVSEupgrade'd adjustable 6-20a L2, 6-13a L1 EVSE
Zencar 13, 20, 30a L1/L2 portable EVSE
GE Durastation 30a

VitaminJ
Posts: 357
Joined: Tue Jan 03, 2017 11:46 am
Delivery Date: 07 Jan 2017
Leaf Number: 415775
Location: Morrison, CO
Contact: YouTube

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

Mon Apr 17, 2017 1:43 pm

It's pretty stupid that the car had 7000wh onboard but cannot keep the 60wh 12v alive running a cooling fan for a few hours. It has been proven earlier in this thread that the OEM 12v battery really only delivers 10Ah of capacity before it can no longer support any functions. It's just plain stupid IMO, and ultimately the reason this very thread exists.

I actually have a few 4S 5000mah Lipos from an RC airplane that I keep in my cars with a modified jumper cable adapter for jump starting. I just keep it in the back at about 65% charge to maximize life and minimize fire risk and it still can deliver enough current to jump start an ICE in winter temperatures.
2013 Ocean Blue SV w/ QC and LED
- +0.2 mi/kwh Aeromods
- Leaf Box
- 2lb 5Ah LiFe 12v battery

Scaramanga
Posts: 107
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

Fri Apr 28, 2017 10:03 pm

I was so fascinated with this thread I joined the forums just to be able to read and respond. Amazing to me that:

1) People are having this struggle with such a basic component of a much more sophisticated vehicle.
2) Folks are so pationate about their arguments and battery theory knowledge.

In my former ICE hobby days, batteries were really just a disposable, if expensive, nussiance. When one went bad or wouldn't charge any more because it was sulfated or whatever, we would just haul it out and go buy another without much thought. Charging systems in European ICE cars I fiddled with just weren't that complicated, and we all learned to fight crusty ground connections first before tossing out the alternator and the like.

I'm really glad (apparently) that I have an SL with a solar cell, apparently that's good. :D

Anyway, pleased to be on the forum, I'm enjoying the battery discussion.
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

strowger
Posts: 6
Joined: Sun Dec 18, 2016 10:59 pm
Delivery Date: 19 Dec 2016

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

Thu May 04, 2017 12:58 pm

jjeff wrote:^^^ I think your right on what might have happened, 5ah isn't much capacity for running a large fan. As a backup should this happen when out and about, I might suggest a smallish portable 12v Li battery jumper. I always carry one in the back of my Leaf for just such occasions. It came with a 12v cigarette lighter adapter or small jumper cables, oh and it also has a 5v USB output for charging portable things that use USB.
All in all for the <$30 I paid for it on sale, I believe $39 regular price, I hope it's worth it, if I ever ran into a weak 12v battery :)
I bought mine at a big box hardware type of store(Menards) but I believe Amazon and other places sell similar models.


Be careful with assuming that those LiIon jump-start packs will jump-start a Leaf with a discharged 12V battery.

The ones I have used, will only output 12V for jump-starting for a second or two - because they are small, their cables are small, and the current required to crank an engine would set fire to them in a few seconds.

The Leaf will not charge a 12V battery which is very deeply discharged - for example, if the voltage is too low. I have seen this with mine when the 12V battery went bad and was down to <11V. The Leaf would "start" on the power button and drive, but the DC-DC converter stayed off, because the 12V battery "looked bad" to the Leaf's electronics.

This second or two of power from a LiIon jump-start pack is not long enough to both power-on the Leaf, and have the Leaf decide the 12V battery is good enough to charge & start charging.

LeftieBiker
Posts: 6557
Joined: Wed May 22, 2013 3:17 am
Delivery Date: 31 May 2013
Location: Upstate New York, US

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

Thu May 04, 2017 3:15 pm

It takes no more than 10 amps to power up a Leaf, so I think the above doesn't apply. The caveat about not saving a dead 12 volt battery does apply.
2013 "Brilliant Silver" SV with Premium Package and no QC, and 2009 Vectrix VX-1 with 18 Leaf cells.

The most offensive, tasteless phrase in use here is "Pulled the trigger." I no longer respond to posts that use it.

arnis
Posts: 713
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

Thu May 04, 2017 4:20 pm

VitaminJ wrote:It's pretty stupid that the car had 7000wh onboard but cannot keep the 60wh 12v alive running a cooling fan for a few hours. It has been proven earlier in this thread that the OEM 12v battery really only delivers 10Ah of capacity before it can no longer support any functions. It's just plain stupid IMO, and ultimately the reason this very thread exists.


Well two days ago I detailed my Leaf (and carpeting measurements for aftermarket special order). I was listening for the radio
for all the time in ACC mode. And had volume cranked up so I wouldn't hear the door open beeping :lol: :lol: 12V battery was supplying juice without DC-DC running. Then I went for a drive. Before doing that I took my DC-ammeter to measure current flow after switching vehicle on. Battery was sucking 30-40A. Though I had no time to measure for long.
It didn't go to 13V mode for few hours though, that I was monitoring. And HV pack was discharging 700-900W while parked (LeafSpy), no AC/fan running, no radio. Only 12V battery charging happening. 14V*40A=500-600W.
Well, I'm absolutely sure I drained much more than 10Ah out of that battery during those hours. 5-6 hours :lol:

Though I have 2014 Leaf. Those have different 12V algorithm than 2011/12.
OEM battery. Made in the beginning of 2014.
Short range EVs <30kWh -- Medium range: 30-60kWh -- Long range: >60kWh
Charging: Trickle <3kW -- Normal 3-22kW -- Fast 50-100kW -- Supercharging >100kW

GerryAZ
Gold Member
Posts: 1339
Joined: Mon Nov 22, 2010 6:47 pm
Delivery Date: 12 Jun 2011
Location: Phoenix, AZ

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

Thu May 04, 2017 6:49 pm

strowger wrote:
jjeff wrote:^^^ I think your right on what might have happened, 5ah isn't much capacity for running a large fan. As a backup should this happen when out and about, I might suggest a smallish portable 12v Li battery jumper. I always carry one in the back of my Leaf for just such occasions. It came with a 12v cigarette lighter adapter or small jumper cables, oh and it also has a 5v USB output for charging portable things that use USB.
All in all for the <$30 I paid for it on sale, I believe $39 regular price, I hope it's worth it, if I ever ran into a weak 12v battery :)
I bought mine at a big box hardware type of store(Menards) but I believe Amazon and other places sell similar models.


Be careful with assuming that those LiIon jump-start packs will jump-start a Leaf with a discharged 12V battery.

The ones I have used, will only output 12V for jump-starting for a second or two - because they are small, their cables are small, and the current required to crank an engine would set fire to them in a few seconds.

The Leaf will not charge a 12V battery which is very deeply discharged - for example, if the voltage is too low. I have seen this with mine when the 12V battery went bad and was down to <11V. The Leaf would "start" on the power button and drive, but the DC-DC converter stayed off, because the 12V battery "looked bad" to the Leaf's electronics.

This second or two of power from a LiIon jump-start pack is not long enough to both power-on the Leaf, and have the Leaf decide the 12V battery is good enough to charge & start charging.


It depends upon the quality of the Li jump starter. I have used mine to start a 4.0L inline 6-cylinder, several different V-8 engines, motorcycles, and my 2015 Leaf (completely dead battery). Both of my Leafs (2011 and 2015) started just fine and recharged their 12-volt batteries after being completely discharged.
Gerry
Silver LEAF 2011 SL rear ended (totaled) by in-attentive driver 1/4/2015 at 50,422 miles
Silver LEAF 2015 SL purchased 2/7/2015

Foschas
Posts: 59
Joined: Thu Jul 30, 2015 6:35 pm
Delivery Date: 31 Jul 2015
Leaf Number: 320277
Location: Mass

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

Fri May 05, 2017 6:26 am

A little OT but tesla is abandoning 12V and CAN Bus in the model Y. Some facts here

https://teslamotorsclub.com/tmc/threads ... l-y.90184/

In today's 1Q conference call, Elon stated that Model Y will not use a CAN bus, and instead use a new high speed bus. He said that while Model S used 3 km of wiring, and the Model 3 uses 1.5 km of wiring, the Model Y will use 100m.

He also said they will finally discard the legacy 12V power, which he derided as saying wasn't the right voltage for anything.

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