P.S. I do not intend to use them in my mods, but this is the only forum where I’m already subscribed and where I might get this information.
View attachment 773399 I have 6 18650 cells from a notebook battery pack that I think should still be ok (the BMS of these packs had the reputation of going bad long before the cells). I have charged them individually and used them a little, but how can I find out what C rating they have? Also, how do I determine their capacity (mAh)? Drain them to a low voltage (how low?) and see how much I can charge them?
P.S. I do not intend to use them in my mods, but this is the only forum where I’m already subscribed and where I might get this information.
Isn’t 2.5 V too low? If I’m not mistaken, the under volt protection of most boards is set at 3 Volts, isn’t it?Drain to 2.5 v and charge to get the mAh rating.
Yes, discharging a battery below 2.5 volts will likely "kill" the battery. I think that was my point about abusing a battery to find the C rating and maximum continuous discharge rating. That is how manufacturers come up with the safety standards of the C rating and CDR.Isn’t 2.5 V too low? If I’m not mistaken, the under volt protection of most boards is set at 3 Volts, isn’t it?
I have 6 18650 cells from a notebook battery pack that I think should still be ok (the BMS of these packs had the reputation of going bad long before the cells). I have charged them individually and used them a little, but how can I find out what C rating they have? Also, how do I determine their capacity (mAh)? Drain them to a low voltage (how low?) and see how much I can charge them?
P.S. I do not intend to use them in my mods, but this is the only forum where I’m already subscribed and where I might get this information.
Not all 18650 cells have the same depth of discharge capabilities.
The data sheet for this cell also shows a discharge cutoff of 3.0V.
Internal impedance of 55 mΩ. Depending application 110mΩ could be considered end of useful life.
These are not particularly good or even decent cells when new, no real reason to 'test' them for another use, recycle.
Sorry, I haven’t seen your question before, but the answer is yes, although some of them came off clean, most of them are still on. Why?If these batteries came from a battery pack, are there still weld marks on the ends of the batteries?
True, that was going to be a problem, good thinking! (Not anymore, since I’m not going to use them at all). Removing them is probably not that difficult, but it has to be done swiftly, I guess, if you don’t wanna damage the cell with the welding iron...Because those weld marks create physical distotions that can negatively affect electrical conductivity and the cells ability to make contact with whatever tool you may have anticipated using them in.
I suspect you are confusing the terms "welding" and "soldering".True, that was going to be a problem, good thinking! (Not anymore, since I’m not going to use them at all). Removing them is probably not that difficult, but it has to be done swiftly, I guess, if you don’t wanna damage the cell with the welding iron...
Yes, thanks! (I wasn’t sure, but I was too lazy to look it up, English isn’t my first language)I suspect you are confusing the terms "welding" and "soldering".