How about how much energy is really left? There was a analysis done in 2014 on lithium batteries (lithium ion was new kid on the block back then). ltihuim batteries starts to crystalizing as soon as it is charged and continues for its life. at 2.5 to 3 years it was 50% crystalized, at 5 years it was 80% crystalized (going off old memory cells here). which is why everyone complained about their cell phones not staying charged as long as it used to. Each new chemistry was trying to slow crystallization. So it would be good to know how much energy is left after so many years (like when does it run out of "gas")?
Lithium Iron Phosphate (LiFePO4) batteries are supposed to retain most of their capacity after thousands of charge/discharge cycles. I have a few papers on the exact number somewhere, so I’ll look it up and publish an article on Lithium battery lifespan soon.
I like the word "most". and what is a thousands of charges really mean (on my cell phone that would be 1 to 2 years worth, on my trailer could be, maybe 5 years)? I was thinking more along the lines of when I start out I would get 10 hours of use in the beginning and then 5 hours of use after 2 or 3 years, then 2 hours of use after 5 or 6 years. Saying how long a battery last or how many charges is meaningless to me, I more interested in how much energy I would have after a time period.
My numbers will be in Ah capacity, so what I’ve seen is something along the lines of a graph showing numbers of charge / discharge cycles with a percentage of original storage capacity. Lithium Iron Phosphate really don’t age in years as much as in cycles. So your mileage will vary depending on how you use them. I’ll try to dig out some data next week.
I know you take all kinds of precautions when doing your tests. But have you ever discussed your tests with the local fire department? I bet they would be interested.
I like how thorough and methodical you're being with this. Good job, Mike!
How about how much energy is really left? There was a analysis done in 2014 on lithium batteries (lithium ion was new kid on the block back then). ltihuim batteries starts to crystalizing as soon as it is charged and continues for its life. at 2.5 to 3 years it was 50% crystalized, at 5 years it was 80% crystalized (going off old memory cells here). which is why everyone complained about their cell phones not staying charged as long as it used to. Each new chemistry was trying to slow crystallization. So it would be good to know how much energy is left after so many years (like when does it run out of "gas")?
Lithium Iron Phosphate (LiFePO4) batteries are supposed to retain most of their capacity after thousands of charge/discharge cycles. I have a few papers on the exact number somewhere, so I’ll look it up and publish an article on Lithium battery lifespan soon.
I like the word "most". and what is a thousands of charges really mean (on my cell phone that would be 1 to 2 years worth, on my trailer could be, maybe 5 years)? I was thinking more along the lines of when I start out I would get 10 hours of use in the beginning and then 5 hours of use after 2 or 3 years, then 2 hours of use after 5 or 6 years. Saying how long a battery last or how many charges is meaningless to me, I more interested in how much energy I would have after a time period.
My numbers will be in Ah capacity, so what I’ve seen is something along the lines of a graph showing numbers of charge / discharge cycles with a percentage of original storage capacity. Lithium Iron Phosphate really don’t age in years as much as in cycles. So your mileage will vary depending on how you use them. I’ll try to dig out some data next week.
Thanks for the update Mike!
I know you take all kinds of precautions when doing your tests. But have you ever discussed your tests with the local fire department? I bet they would be interested.
The local fire company in Funkstown is literally 1,000 feet from my house. And they all know me.