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Re: Replace small 12v battery to regular one.

Posted: Sun Jul 08, 2018 9:31 am
by bitmanEV
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 :)

Re: Replace small 12v battery to regular one.

Posted: Sun Jul 08, 2018 9:39 am
by Stanton
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).

Re: Replace small 12v battery to regular one.

Posted: Sun Jul 08, 2018 3:14 pm
by Markokk888
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.

Re: Replace small 12v battery to regular one.

Posted: Mon Jul 09, 2018 7:50 am
by jlv
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).

Re: Replace small 12v battery to regular one.

Posted: Mon Jul 09, 2018 1:29 pm
by arnis
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

Re: Replace small 12v battery to regular one.

Posted: Sat Apr 13, 2019 5:14 am
by bitmanEV
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

Re: Replace small 12v battery to regular one.

Posted: Sat Apr 13, 2019 7:14 am
by Marktm
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%

Re: Replace small 12v battery to regular one.

Posted: Sat Apr 13, 2019 9:57 am
by downeykp
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.

Re: Replace small 12v battery to regular one.

Posted: Sat Apr 13, 2019 10:29 am
by Marktm
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.

Re: Replace small 12v battery to regular one.

Posted: Sat Apr 13, 2019 10:33 am
by arnis
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.