bitmanEV
Posts: 40
Joined: Tue Aug 23, 2016 10:56 am
Delivery Date: 30 Aug 2016
Location: Redhill, UK

Re: Replace small 12v battery to regular one.

Sun Jul 08, 2018 9:31 am

arnis wrote:Easy fix is to disconnect current sensor and all you guys will be happy with OEM battery
being heavily charged like with good ol' gasoline car.


i have just done that and will keep an eye on my OEM battery for now to see if it indeed an improvement :)
Next EV - Byton M-Byte reserved
Nissan Leaf MK1 - Japan build
Renault Zoe R240 - ditched after 8k Miles due crap quality / DS65 WBL
Toyota Rav4 (ICE) SWMBO (rock solid)
Subaru Forester - PX for EV (ODO 200.000+ Miles)
Driving BEV since Dec 2015

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Stanton
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Posts: 2141
Joined: Thu Feb 03, 2011 10:56 am
Delivery Date: 01 Sep 2011
Leaf Number: 7458
Location: Plano, TX
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Re: Replace small 12v battery to regular one.

Sun Jul 08, 2018 9:39 am

Leaf15 wrote:Replaced with exact fit 12V 46Ah 650A Lithium Iron Phosphate Battery LiFePO4 and never looked back. Always 13.35V when parked.


I have done the same with a LiFePO4 battery about half the "size" (20AHr) with no issues; you can search for the thread I started over 3 years ago if you wish. Remember: the Leaf doesn't require "cranking Amps" like an ICE car; Nissan just put something similar to what they already use in their low-end compact cars (high-volume, low cost part).
2011 Blue Ocean SV w/floor mats & window tint
12v LiFePO4 battery & FIAMM 74100 horns
Wet Okole seat covers (front)
Tor's low-power heater mod
2013 sun visor
3G modem upgrade
L2 EVSE Upgrade
Battery Pack replaced (Rev E) @51 months and 41k miles

Markokk888
Posts: 19
Joined: Wed Mar 21, 2018 4:16 pm
Delivery Date: 21 Mar 2017

Re: Replace small 12v battery to regular one.

Sun Jul 08, 2018 3:14 pm

arnis wrote:Easy fix is to disconnect current sensor and all you guys will be happy with OEM battery
being heavily charged like with good ol' gasoline car.

Yeah right and if its a lithium battery it will soon release a magic smoke and probably get the whole car on fire... Ether way the error code will appear as the current sensing is not gonna make much sense to the on board computer.. the car can even refuse to even charge the battery on some models. i suggest to not do something stupid like this. This is not old gasoline car. And things don't work quit as same.

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jlv
Posts: 1005
Joined: Thu Apr 24, 2014 6:08 pm
Delivery Date: 30 Apr 2014
Leaf Number: 424487
Location: Massachusetts

Re: Replace small 12v battery to regular one.

Mon Jul 09, 2018 7:50 am

I keep an eye on these threads for the day when I will have to replace the 12V battery. Over 4 years and the car still has the original OEM 12V battery. It has never had a problem other than the first time the 3G TCU locked up and caused the battery to go low (lots of DTCs).
LEAF '13 SL+Prem (mfg 12/13, leased 4/14, bought 5/17, sold 11/18) 34K mi, AHr 58, SOH 87%
Tesla S 75D (3/17)
Tesla X 100D (12/18)
75K 100% BEV miles since '14
ICE free since '18

arnis
Posts: 953
Joined: Sat Jan 23, 2016 3:21 pm
Delivery Date: 23 Jul 2014
Leaf Number: 015896
Location: Estonia, Europe

Re: Replace small 12v battery to regular one.

Mon Jul 09, 2018 1:29 pm

Markokk888 wrote:
arnis wrote:Easy fix is to disconnect current sensor and all you guys will be happy with OEM battery
being heavily charged like with good ol' gasoline car.

Yeah right and if its a lithium battery it will soon release a magic smoke and probably get the whole car on fire... Ether way the error code will appear as the current sensing is not gonna make much sense to the on board computer.. the car can even refuse to even charge the battery on some models. i suggest to not do something stupid like this. This is not old gasoline car. And things don't work quit as same.


Your talk is based on what knowledge or education? If it is assumption/guessing, then let it be that.
If you don't know how to use multimeter, then don't state those things you just said :| Myth generation
Short range EVs <30kWh -- Medium range: 30-60kWh -- Long range: >60kWh
Charging: Trickle <3kW -- Normal 3-22kW -- Fast 50-100kW -- Supercharging >100kW

bitmanEV
Posts: 40
Joined: Tue Aug 23, 2016 10:56 am
Delivery Date: 30 Aug 2016
Location: Redhill, UK

Re: Replace small 12v battery to regular one.

Sat Apr 13, 2019 5:14 am

bitmanEV wrote:
arnis wrote:Easy fix is to disconnect current sensor and all you guys will be happy with OEM battery
being heavily charged like with good ol' gasoline car.


i have just done that and will keep an eye on my OEM battery for now to see if it indeed an improvement :)


well 9 mouths later; i can confirm that i have not had any 12 volt battery problems after this simple mod 8-)
even over Christmas the Leaf stood even still for 4 weeks due holiday's without charging with no issues to report
Next EV - Byton M-Byte reserved
Nissan Leaf MK1 - Japan build
Renault Zoe R240 - ditched after 8k Miles due crap quality / DS65 WBL
Toyota Rav4 (ICE) SWMBO (rock solid)
Subaru Forester - PX for EV (ODO 200.000+ Miles)
Driving BEV since Dec 2015

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Marktm
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Posts: 478
Joined: Thu Jan 21, 2016 10:49 am
Delivery Date: 09 Jan 2016
Leaf Number: 022737
Location: Houston, TX

Re: Replace small 12v battery to regular one.

Sat Apr 13, 2019 7:14 am

Although the charge profile is not optimal for a FLA style battery (on my 2012 Leaf), the OEM battery lasted 6 years - likely the longest auto battery life from any that I've ever owned! I replaced it with the cheapest FLA battery I could find (Costco). We'll see if the quality of this cheap one is as good as the OEM battery.

Charge profile not optimal? On my Leaf, the battery SOC was kept at levels that (theoretically?) degrade the life (by sulfation) the majority of it's life. However, good care (water levels) and low stress usage may have offset the degradation mechanisms?

BTW, I have a permanent trickle charge wiring system to conveniently charge the 12V battery most times when I don't plan on using my Leaf for a few days to build back the SOC to 100%
2012 Leaf SL; 43,000 miles. Battery replaced November 1st, 2016.

downeykp
Forum Supporter
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Joined: Wed Nov 24, 2010 9:11 am
Delivery Date: 31 May 2011
Leaf Number: 1931
Location: Keaau, HI

Re: Replace small 12v battery to regular one.

Sat Apr 13, 2019 9:57 am

My 2011 with 34000 mi and 7 bars has original battery. Never had a problem with it. I also put float charger on it for 3 months every September when I travel to the mainland.
2011 Black Leaf SL+QC Vin. 1931
Res. 6-14-10 Order 1-25-11
EVSE: Mod'd Ver. 2 Nissan L1
Delivered 5-31-11

8 years 33000mi. 7 bars

39 Suniva panels 10.3kw with Enphase micro inverters my electricity cost $26 a month.

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Marktm
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Posts: 478
Joined: Thu Jan 21, 2016 10:49 am
Delivery Date: 09 Jan 2016
Leaf Number: 022737
Location: Houston, TX

Re: Replace small 12v battery to regular one.

Sat Apr 13, 2019 10:29 am

downeykp wrote:My 2011 with 34000 mi and 7 bars has original battery. Never had a problem with it. I also put float charger on it for 3 months every September when I travel to the mainland.


Yea, my guess is that if I'd been the original owner and float charged every few weeks/monthly, the OEM battery would still be working. It certainly appeared to be a well constructed battery.
2012 Leaf SL; 43,000 miles. Battery replaced November 1st, 2016.

arnis
Posts: 953
Joined: Sat Jan 23, 2016 3:21 pm
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Leaf Number: 015896
Location: Estonia, Europe

Re: Replace small 12v battery to regular one.

Sat Apr 13, 2019 10:33 am

Leaf and many modern vehicles charge 12V battery to very optimal state of charge, around 80%.
Problem arises when vehicle is not being used on daily basis.
Some vehicles, like Tesla, have heavy vampire drain. If car software doesn't recharge 12V battery often when
vehicle not in use, 12V battery will take a hit.

13.0V float charging voltage is near ideal for current lead acid batteries that are used DAILY.
For those being slowly discharging for many days when vehicle stationary, 14.4V charging voltage will give a better buffer
for deeper discharge during those idling days. This is why disconnecting current sensor will help.

14.4V is slightly too much for daily "many hour float charge when Li-ion battery is being charged overnight".
Especially in hot weather.
14.4V is fine if vehicle is charging 1-30 hours each week ( up to 4h per day) - it's fine to unplug current sensor.
14.4V is too much if vehicle is charging every day for more than 5 hours and it's hot - keep the sensor plugged in.

@bitmanEV - thanks for feedback. I was sure then and now it has been confirmed by you :)

My Leaf is 5 years old and runs on original battery which is in a good state (measured).
For 5 months in a year I have winter and vehicle keeps 14.4V mode on anyway. Can't bypass that.
Short range EVs <30kWh -- Medium range: 30-60kWh -- Long range: >60kWh
Charging: Trickle <3kW -- Normal 3-22kW -- Fast 50-100kW -- Supercharging >100kW

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