lithium battery longevity

[ARoamer]

Being that lithium iron phosphate batteries have been making it into many RV's, I'm wondering how they are performing. With many battery sellers stating a service life of decades, I hope this question is premature, but...

Has anyone had failures, even owner induced, noticed any reduced capacity, or any other general problems?

[ependydad]

My BattleBorns were solid from when I bought them in 2017 until I sold that rig in 2021, so 4 years of use.

My lithium cells/DIY custom battery bank is being wonky at the moment. But I'm assuming that's me more than anything else as it's only 8 months old.

[Jerry713]

I'm on a fishing forum and lots of guys use lithium batteries and claim of 5 plus years of often use (including the trolling motor) and still going strong. I think LiFePO4 batteries will give you longer life than lithium iron phosphate batteries will especially for those boon docking where 12 volt is used a lot more. Most I've seen base their life span off of charge cycles but obviously how they are used and maintained will affect the life span as well.

Here's a LiFePO4 100 ah that advertises over 4000 charge cycles. I know nothing about this battery just did a quick search. https://www.amperetime.com/products/...RoCm-QQAvD_BwE

[ARoamer]

Originally Posted by Jerry713

Here's a LiFePO4 100 ah that advertises over 4000 charge cycles. I know nothing about this battery just did a quick search. https://www.amperetime.com/products/...RoCm-QQAvD_BwE

No low temp cutoff or bluetooth monitoring on that battery. Overseas?? phone number with no physical adress, I'd avoid that one!

"" Our battery can be used well below 0C (can be normally discharged), but we don’t suggest charging the battery below 0C. It is like most kinds of the battery in the market now""

False statement! Most decent lithium batteries have low temp cutoff!

[billcf7]

I plan on purchasing 2 300 A/H Enduro Power LIFEPO batteries. 10 year warranty Made in USA

https://www.enduropowerbatteries.com/pages/resources

[craigav]

I have around 20 LifePo4 batteries that I use for different purposes on my ranch here. Some for lights, electric fences, gates, and standby power (via inverter), bass boat trolling motor, etc.

In any case, some of them that I have are now 20~22 years old (based on date codes on the battery) that I purchased from a medical supply house over the course of the last ~15 years as I was told, for medical use these batteries are required to be replaced after only a few years of usage regardless of their condition (or capacity).

The oldest batteries I have are at about 80% of their rated capacity however some of them are still 90% or better even after 10~20 years of age. I do not know the cycle count on any. Some of them have a connection where with the proper tool the cycle count can be determined. I don't have such a tool to read them, however I do have a Battery capacity tester which works very well... well enough I suppose as I did have to repair the power supply in it after about a year of usage and since then I haven't had any failures. EBC-A10H is the tester and it outputs a capacity graph on my laptop which is pretty cool.

About ~6 years ago I purchased 3 cheap chinese 100a LifePo4 batteries. One of them now only has about 30% capacity, one has bulged and no longer in use (I plan to charge it up as much as possible and use it for target practice to see what happens), and the third is still in use in my RV and I haven't tested it lately but about a year ago it was still at around 90%.

From my experience, most all LifePo4 batteries can last a very long time. Unlike a lead acid battery, LifePo4's don't often go completely bad and instead they simply lose capacity. Most manufactures state the life of one is over at ~80% but the reality is that they can last a lot longer (decades longer perhaps) but just at a lower capacity. For example, many of the older ones that I have were 50ah batteries new that now have a capacity of around 40ah. I wouldn't be surprised to get another 20 years on them with another 20% drop over the 20 years.

The older batteries I have were basic batteries with no frills (although they do have a test port on them if I had a tester which would show the cycle count). The older LifePo4 batteries commonly use an array of cylindrical cells inside about the size of a C-D cell battery, the newer ones use a rectangular prismatic battery inside. There isn't a whole lot of difference with either type although the rectangular generally have more capacity for their size.

Just for another thought, many that I purchased I got at a steal of a deal, 10~20$ each for 50ah batteries. The reason is that the medical supply house started wholesaling them to a recycle center and that place used a load tester on the batteries which was made for lead acid batteries. Doing that most often blew the fuse internal on the BMS board which was easy to replace once I was able to open the battery case. A couple had blown transistors on the BMS board, however none of that would have happened had they not tested them the way they did, but in doing so I was able to purchase many of these for a very low price.

If I get back into boondocking (perhaps better states as "when"), I will likely parallel ~10 (or more) of them for a ~400ah bank. Otherwise I will just use them for projects and for emergency power with an inverter. The 50ah batteries are almost exactly half the size of a 100a LifePo4 battery along with almost half the weight.

In summary, I have no reason to doubt that a LifePo4 can last decades with around 10% less capacity per decade. However, that statement is based on proper care of them which means not to overload them, not to overcharge them, and to store them at around 60~70% of their capacity when they will not be used for a few weeks or more... ps: it is hard to know when they are at 60~70% without a tester. ~CA

btw, don't count on the BMS to prevent over charging or over discharging. The BMS in all that I have tested are more for preventing the most damaging aspects. In other words if the battery becomes disconnected via the BMS due to high or low battery voltage, while that will protect the battery overall, the battery longevity will be diminished with such a high or low voltage vs not allowing the battery to reach such a high or low voltage in the first place.

[colby]

Originally Posted by ARoamer

No low temp cutoff or bluetooth monitoring on that battery. Overseas?? phone number with no physical adress, I'd avoid that one!

"" Our battery can be used well below 0C (can be normally discharged), but we don’t suggest charging the battery below 0C. It is like most kinds of the battery in the market now""

False statement! Most decent lithium batteries have low temp cutoff!

This battery has been used by a lot of members in a Solar and Boondocking group that I belong to with no issue, and they have received great customer support.

And lots of batteries don't have a low temp charging disconnect (like this one - https://www.renogy.com/12v-200ah-lit...y-w-bluetooth/). You get what you pay for. You want low temp disconnect in the BMS, that is more, you want a higher amp BMS, that will be more, self heating? Even more...

[mini4mw]

As a note on the amperetime batteries.. I have 2 12v 300amp hour w/ 200amp BMS and they run very well. Email support is good too, usually a response within 12hrs. They don't have an internal heater, but I just attached a Victron battery sense and networked to the Victron MPPT and have the charging auto cut off when temp goes below 40. Not ideal for an RV if you go to cold areas, but they are decent batteries. I can fire up both AC units in my RV while connected to this setup going through a 4000W inverter, but not for long.. Just did that for load testing.

The amperetime don't have internal heaters or internal low temp cut off, just high temp, or at least when I bought them 2 years ago.

[Jerry713]

Originally Posted by craigav

it is hard to know when they are at 60~70% without a tester. ~CA.

You have a lot of experience with these batteries. Do you have a tester and lithium charger you recommend?

[ARoamer]

Originally Posted by craigav

I have around 20 LifePo4 batteries that I use for different purposes on my ranch here. Some for lights, electric fences, gates, and standby power (via inverter), bass boat trolling motor, etc.

Thank you for the informative detailed post, exactly what I was looking for.

[craigav]

Originally Posted by Jerry713

You have a lot of experience with these batteries. Do you have a tester and lithium charger you recommend?

Not necessarily what I recommend as I don't really have a recommendation, but here is what I use. You really need a laptop connection to use this one but you could do everything from the panel control. Using a laptop allows for much better logging and control. This one can do a lot more than way more expensive testers but I rarely use it for charging, more for testing.

For charging when RV'ing, I use the RV's onboard converter most often.

https://www.amazon.com/EBC-A10H-Batt...0-4513d670b6bc

[Eric H.]

Originally Posted by Jerry713

I'm on a fishing forum and lots of guys use lithium batteries and claim of 5 plus years of often use (including the trolling motor) and still going strong. I think LiFePO4 batteries will give you longer life than lithium iron phosphate batteries will especially for those boon docking where 12 volt is used a lot more. Most I've seen base their life span off of charge cycles but obviously how they are used and maintained will affect the life span as well.

Here's a LiFePO4 100 ah that advertises over 4000 charge cycles. I know nothing about this battery just did a quick search. https://www.amperetime.com/products/...RoCm-QQAvD_BwE

Lithium Iron Phosphate is LiFePO4.

[RogerR]

I got my Renogy Lithium and 200 watts of solar. I don't use huge amount such as microwave, coffee pot or 12 volt refrigerator but have never seen my battery go below 45 amps while camping with no other source but solar.

Mine is the least expensive Renogy and does not have heating but it does have a BMS that prevents charging below 32 degrees. If you will do camping below 32 then an upgrade to a heated battery may be a good idea.

If you like Renogy get a referral from someone like me who bought Renogy in the past and you can get a 7% discount on top of any current sale prices.