Lithium based batteries

[Rod Johnson]

https://www.solacity.com/how-to-keep-lifepo4-lithium-ion-batteries-happy/#End

I was looking for general information with respect to the reliability of terminal voltages, with respect to LiFePO4 batteries.

  I had seen, but not saved, various charts stating the percentage charge remaining, with respect to the terminal voltages, and was wanting to compare the various charts I had seen.

  In the process of digging around the 'infernalnet', I ran across this web site.  Yes, it is 'Canadienne', and a bit of advertising.  It is also well written, but not very technical ( no significant 'math'  is involved)  

   There is a large amount of useful information about the charging, discharging, and maintenance of our LiFePO4 batteries, and some not so common knowledge about the Battery Management System(s) (BMS) in nearly all the batteries with the lithium based chemistry.   

  Something I had not considered ( series stringing a pair 12volt batteries, to make a 24 volt string), has some significant potential drawbacks.  I will not go into the details, but it was a bit of an 'AHA' moment for me, and it is a very simple consideration. ( insert:  Review basic BMS operation, here).

  I would encourage anyone with an hour of extra time, and an interest, to learn about LiFePO4 batteries, the relative costs, advantages and disadvantages, and how to get use of most of the charge/discharge cycles they have been designed with.

 Rod J  

[Paul Butzi]

One thing I’d take issue with in that presentation is the suggestion that you can rely on the BMS to prevent charging when the cell temp is below freezing.  That’s not true for many lower priced LiFePO4 large capacity batteries (e.g. the cheap ones off Amazon) and I am not confident that the BMS in the smaller Bioenno batteries provides a low temp cutoff.

-p W7PFB

73, don’t forget to smile and have fun!

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[Rod Johnson]

Paul,

   Thank you, and I  completely agree. 

I found it an easy read, and a good overall description of the subject, but it is still had a suttle bit of self-promotion.

Yes, not all LiFePo4 batteries are  built the same.  I have a couple of older Bioenno's ( a 40, and a 50AHr).  There is no mention of cold weather shut-down in their literature.

A while ago, when I was looking,  I did see some of the larger batteries, even on Amazon, do mention freeze protection and built-in heaters.

  

Rod J

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