The not charging below freezing requirement, all by itself, makes LiFePo4 batteries a nonstarter (so to speak) in much of North America. They would have to be equipped with heaters that would drain them if not used every week in frigid weather, or that would drain charge from the main pack.I have studied the idea of replacing the group 51R battery in the Nissan Leaf and other than the increased expense, I find little reason not to swap out the Lead battery for a good quality LiFePO4 battery, provided the mandatory BMS can guard against the environment of useage, i.e., it must not allow charging below freezing and must limit operations that can cause damage to the cells.
Is this stuff from Battery University? Because they are not the best source of information on batteries. The above is close to worst-case scenario for lead-acid batteries. I've gotten 7+ years from them in ICE vehicles, and a properly sized, good quality 51R can easily last 5 years in a Leaf. A good SLA battery can go six months disconnected without losing more than 5-15% of charge. If you want to compare $75 Chinese brand starting batteries with $400 lithium batteries, be sure to include the warning that sometimes a lithium battery's BMS will fail and kill the battery all by itself; one of the alternate acronyms for "BMS" is "Battery Murdering System." The best, most cost-effective way to deal with a Leaf that is getting dead batteries is:Some of my findings are surprising; for example; the 51R Lead battery, used in the Leaf, is rated at about 40 amps; but only about half that capacity is truly usable; a Lead battery loses about 1% per day capacity through internal leakage and if not continuously kept fully charged, builds up a sulfur coating over the negative plates and shredding of the positive plates that in time short out the battery; a Lead battery is always chemically active and starts the process of degradation the day acid is added to the core and depending on it's usage can last for periods on average of 3 years.
Price aside, this BMS requirement is the reason I have not swapped. And even if the 12v has its own reliable BMS, I'm left with the problem of cold spells in the winter when the 12v cannot charge.
Been using mine (which is only a 20ah version) for I think 6 years now without any single issues, my wife on the other hand has gone through several lead-acid batteries in her leaf, not to mention the dead time and helped needed to jump start her car so she could drive. I'm actually going to move it from my 2013 to my 2020 Leaf shortly because I want to see how long the thing will live I still have the old lead-acid battery on a tender in the garage to keep it healthy in case my wife needs another replacement (which at the rate I check it, she probably will in about another year )fotajoye wrote: ↑Sat Feb 27, 2021 1:04 amIf you are using a LiFePO4 12 volt battery in your Leaf, please let us know the particulars of your selection and its performance history. I would like to, in time, find a less expensive LiFePO4 battery that will fit the service requirements of the Nissan Leaf.
Not sure if this is just a fluke but I also had my old lead-acid battery on a tender in the garage, probably for a couple of years? but I looked at it the other day and it was several inches low on acid, well below the plates Needless to say, I unplugged it and promptly recycled it as I can't believe it's good anymore. I had always thought I was doing good keeping it on a tender but apparently not? now I'm going to have to check my X-1/9 this spring, I've had it on a battery tender for probably 4 years, again thinking I was doing good. I'll be kind of PO'd if its battery is also dry!
As far as I know, if it's a flooded battery then you need to check electrolyte level periodically even if it's just on a float charge. If the charger has any "desulfating" chicanery then probably need checking more frequently.jjeff wrote: ↑Sat Feb 27, 2021 2:46 pmNot sure if this is just a fluke but I also had my old lead-acid battery on a tender in the garage, probably for a couple of years? but I looked at it the other day and it was several inches low on acid, well below the plates Needless to say, I unplugged it and promptly recycled it as I can't believe it's good anymore. I had always thought I was doing good keeping it on a tender but apparently not? now I'm going to have to check my X-1/9 this spring, I've had it on a battery tender for probably 4 years, again thinking I was doing good. I'll be kind of PO'd if its battery is also dry!
The link spec is 8.5 Lbs.bobkart wrote: ↑Sat Aug 03, 2019 9:23 pmThis is the battery I went with:
https://www.ohmmu.com/product-page/12v- ... la-model-3
Yes to your last point, both my float chargers have the occasional pulse for desulfating. Like I said too late for my one battery, I just hope I haven't hurt my X-1/9 battery as that one was almost new when installed. I unplugged that tender a couple months back when I noticed my other battery was very low on acid. Probably should plug it in again for a couple days, then unplug it. I'd check that battery but it's under lots of light things stacked on the hood(where the battery is under) and the car has a cover on it, sounds like a spring project to check that battery.