Dr. Dickie
Member
- Joined
- Sep 23, 2020
- Messages
- 363
With HBs thread scaring the ap out of me.
I have tested or are in the process of testing about 2 thousand cells.
Of course I did many things wrong, but am getting up to speed and trying to rectify things. I have gone back and determined IR on all the cells that I capacity tested before knowing to do that.
My process has been:
1) Charge up (only cells with voltage above 1 V--slow charge and then up)--probably 95% above 2V
2) Capacity test through discharge (Opus),
3) RE-charge and measure IR.
4) Let them sit for about 25 days and toss any that are below 4.15 V
5) Hold for building
I have not, nor do I have a method of testing to see if they are heaters
So, I have several questions.
Will IR testing and self-discharge pick up any bad cells that would be potential heaters? My though is, the heat is result of high internal resistance with either self-discharge of just a short.
If not, I am getting two MegaCellChargers, which I understand monitors and records temperature during test.
So, would it be wise to just go ahead and re-test all the cells with the MegaCellChanrger? And if I do, how high of a temp constitutes a heater?
And, after you test your cells for self-discharge, do you discharge them to 3.6V for storage until you build your packs?
Thanks to all here as I have learned a lot. In fact, I have learned enough to have the questions above.
I have tested or are in the process of testing about 2 thousand cells.
Of course I did many things wrong, but am getting up to speed and trying to rectify things. I have gone back and determined IR on all the cells that I capacity tested before knowing to do that.
My process has been:
1) Charge up (only cells with voltage above 1 V--slow charge and then up)--probably 95% above 2V
2) Capacity test through discharge (Opus),
3) RE-charge and measure IR.
4) Let them sit for about 25 days and toss any that are below 4.15 V
5) Hold for building
I have not, nor do I have a method of testing to see if they are heaters
So, I have several questions.
Will IR testing and self-discharge pick up any bad cells that would be potential heaters? My though is, the heat is result of high internal resistance with either self-discharge of just a short.
If not, I am getting two MegaCellChargers, which I understand monitors and records temperature during test.
So, would it be wise to just go ahead and re-test all the cells with the MegaCellChanrger? And if I do, how high of a temp constitutes a heater?
And, after you test your cells for self-discharge, do you discharge them to 3.6V for storage until you build your packs?
Thanks to all here as I have learned a lot. In fact, I have learned enough to have the questions above.
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