knightmb
Posts: 658
Joined: Mon Jan 12, 2015 7:41 pm
Delivery Date: 26 Feb 2021
Leaf Number: 306291
Location: Franklin, TN

Re: Replacing 12V Battery with LiFePO4 (Video)

Tue Mar 02, 2021 6:55 am

SageBrush wrote:
Tue Mar 02, 2021 6:29 am
I agree that a 20 Ahr LFP battery that can handle the cold would probably work great in the LEAF and outlive the car. My LEAF is a 2013. It currently has a shitty walmart battery that is 3 years old that I am testing this week. I expect to either replace it soon or before the next winter. I figure that a better AGM PbA will last ~ 4 years, which is about how long I expect to keep our LEAF so the extra cost of an LFP has unclear benefit in my case.

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As an aside, LFP is cheaper than PbA on a kWh basis as a commodity. I don't know of any reason why LFP will not eventually be the cheapest and best option.
Good advice. When I traded in my 2013 Leaf for a 2020 (in 2021), I just transferred my old LFP from the 2013 to the 2020 and put the new lead-acid the 2020 came with in storage with a tender. I did a capacity test on my old LFP (with was only rated for 20ah) before doing it because I wanted to see what nearly a decade of use had done to it capacity wise. To my surprise, it came up close to the original 20ah (technically I got 19.29 before it hit the safe discharge voltage cut-off) It cost a lot more years ago, but appears to be a good gamble with years of service without a single hiccup. Well worth it to me not to have to keep changing out lead-acid batteries over the years both labor and cost wise. :mrgreen:
2020 Leaf SL Plus

SageBrush
Forum Supporter
Posts: 5956
Joined: Sun Mar 06, 2011 2:28 am
Delivery Date: 13 Feb 2017
Location: NM

Re: Replacing 12V Battery with LiFePO4 (Video)

Tue Mar 02, 2021 8:30 am

knightmb wrote:
Tue Mar 02, 2021 6:55 am
I just transferred my old LFP from the 2013 to the 2020 and put the new lead-acid the 2020 came with in storage with a tender. I did a capacity test on my old LFP (with was only rated for 20ah) before doing it because I wanted to see what nearly a decade of use had done to it capacity wise. To my surprise, it came up close to the original 20ah (technically I got 19.29 before it hit the safe discharge voltage cut-off) It cost a lot more years ago, but appears to be a good gamble with years of service without a single hiccup. Well worth it to me not to have to keep changing out lead-acid batteries over the years both labor and cost wise. :mrgreen:
Yes indeed, and impressive report on longevity. The price is a lot more palatable when you have a reasonable expectation of being able to move an LFP 12v from current car to next car.
2013 LEAF 'S' Model with QC & rear-view camera
Bought Jan 2017 from N. California
Two years in Colorado, now in NM
03/18: 58 Ahr, 28k miles
11/18: 56.16 Ahr, 30k miles
09/20: 54.3 Ahr; 38k miles
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2018 Tesla Model 3 LR, Delivered 6/2018

User avatar
Nubo
Posts: 5908
Joined: Fri May 28, 2010 11:01 am
Delivery Date: 31 Oct 2014
Location: Vallejo, CA

Re: Replacing 12V Battery with LiFePO4 (Video)

Tue Mar 02, 2021 12:14 pm

SageBrush wrote:
Tue Mar 02, 2021 6:29 am
... I figure that a better AGM PbA will last ~ 4 years, which is about how long I expect to keep our LEAF so the extra cost of an LFP has unclear benefit in my case. I've about decided on this replacement:
https://www.remybattery.com/batteries/b ... -html.html ...
92AH in a 51R Pb automotive battery? I suspect that's a mistake. Manufacturer's spec is 46AH (still good!)
https://www.eastpennmanufacturing.com/w ... -Sheet.pdf
I noticed you're still working with polymers.

SageBrush
Forum Supporter
Posts: 5956
Joined: Sun Mar 06, 2011 2:28 am
Delivery Date: 13 Feb 2017
Location: NM

Re: Replacing 12V Battery with LiFePO4 (Video)

Tue Mar 02, 2021 1:55 pm

Nubo wrote:
Tue Mar 02, 2021 12:14 pm
92AH in a 51R Pb automotive battery? I suspect that's a mistake.
Yeah, I saw that too.

They call it a 'rate' which I don't understand. Mostly I decided to ignore that number but my *guess* is that it is peak Amps for longer than the cranking Amps, extrapolated out to (the unachievable) one hour. Or something close but not interesting.

It reminded me of the Tesla advert of 1000 miles range per hour charging ... if you could manage 250 kW continuous for an hour, which you cannot.
2013 LEAF 'S' Model with QC & rear-view camera
Bought Jan 2017 from N. California
Two years in Colorado, now in NM
03/18: 58 Ahr, 28k miles
11/18: 56.16 Ahr, 30k miles
09/20: 54.3 Ahr; 38k miles
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2018 Tesla Model 3 LR, Delivered 6/2018

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