I’m capacity testing all my batteries, my heavily used laptop pulls are sanyo purple ring (2250mAh).
They are testing between about 1200-1450mA (and don’t put out full brightness as tested by hand burning heat on a Convoy S2).
One read 485mAh, an unused one in storage (at 3.8V), but i plan on cycling it a few times and retesting it.
Me personally, I have no equipment to test the cells. I’ll usually do a runtime test of a new cell in one of my lights and note it. Then when it ‘seems’ to get noticeably shorter I recycle it and get another. That comes out to every 2 years for my cells when I start noticing shorter runtimes. Then off to recycling they go and replaced with fresh newer cells that are better than the previous because of the advancements in 18650. Btw, I only have and use 4-6 18650s at a time.
Your tired cells test at twice the capacity of the average UltraFire cells I have seen.
In fact the highest UF I ever tested was 2000mAh so I wouldn’t settle for anything less than that.
But, if that is all you have and you can’t get better ones, they work. Right?
So what I am suggesting is be on the lookout for better cells and when you find them, cycle them into your rotation and eliminate the poorest performing cells as you go.
I have 13 18650s, 4 have been capacity tested so far, but they are the worst of the bunch (from the same laptop pull), all 4 seem to be now getting quite hot when charging where they were not before, maybe they got used to 4.05V so 4.2V is stressing them somehow? I am considering recycling all 4.
Twice the capacity of ultrafire, thats nuts
I usually dispose of laptop pulls if they are under 1700mah capacity, measured in my hobby charger.
My hobby charger when discharging seems to indicate approx 10% less capacity with a new cell than than HKJ gets in his tests.
Interesting, i bought a Liitokala 300 which tests capacity, it just came the other day.
I am surprised to hear yours reads lower then HKJs equipment, i assumed current measurement was more exact.
I just like to see cells that have been sitting there for a couple weeks not self-discharge below about 4.1 V. It’s nice to be able to test them on the analyzying charger and I mostly go by that, but I don’t trust any cell that self-discharges too fast. Also, if there’s any doubt, they get recycled. NiMH I basically run into the ground, but not lithium-ion.
i found my testing of 18650s weird. Some of the oldest laptop pulls i have still tested with 1900mah or higher, and some newer ones less. My best cells are the loose-purchased samsung 20Rs, 25Rs, Panasonic protected cells, and newest ones purchased recently, but i still have some old ones that test good. I have recycled all the ones i have that tested less than 1100 mah.
The most unusual pulls were six green CGR18650CG light green wrapped 18650s that came from a old Laptop pack with all of them discharged to average of 2 volts each, they all recovered, tested at 2250mah and up, (near their factory rating) and a 100 or less IR, and hold their charge very well. ( all charging and tests are done with an OPUS BT3100C)
EDIT: I just checked their voltage after 2 months of storage, and they all are still at 4.17 volts.
It only tests liIon to 3.0 volts. some batteries need to go below that to show maximum capacity. On the other hand most LEDs lose significant brightness well before 3.0 volts, so I've been happy just to measure useful capacity.
I use the Opus and it’s been a good charger.
very interesting, do you find your lower testing cells heat up quite a bit during charging?
For some reason all the cells i have tested so far get too hot to hold, though all 4 are from the same laptop pull
Bort, those cells that heat up like that are definitely NG. You need to get them out of the house!
Please
I plan to, this just started today, none of these cells have been fully charged in the 3 years i’ve had them (two were recycled a few months ago), all my chargers before now never hit 4.2V.
I’ve already drained one in a flashlight (and taped the ends), because i assume tossing fully charged cells is a very bad idea
There is a saying you have probably heard already
“If you fail to plan, you plan to fail”
In this case I recommend that you do NOT plan, I recommend that you do
That heat could be a combination of the charging current passing thru the cells elevated internal resistance, or worse still, leakage internally that could suddenly run away in a catastrophic manner.
indeed, as a systems thinker i completely understand what your saying (two more to drain)
I have to admit i am afraid of testing my other cells in case they do the same thing and i end up with no batteries left, but the various li ion explosion threads have convinced me to not even give a li ion flashlight to a non enthusiast, there is just too many things that can go wrong.
Just some of the lower-tested ones, ( ones that were below 1000mah) got warmer than the better newer ones, but i recycled all those that got warmer than normal. I usually use an external fan to keep all my batteries as cool as possible while charging, especially my NiMH cells, those can get really hot, even the newer ones.
To answer the OP ; as soon as I see “Ultrafire” on the wrapper :bigsmile:
Depends on the equipment, hobby chargers are not precision equipment and the calibration can be way off.
I do my recharging here at my desk while I’m playing working, online just so I can reach over and feel the cells for heat while they’re charging. I wouldn’t let one even get close to being too hot to touch- it’s simply not worth the risk to me or my charger.
Excess heat indicates too much charging or too much resistance in the cell, so if the charger is OK then the cell is bad. I hate wasting things, but I’d rather “waste” a cell by junking it early than waste my charger or my health if things ‘go boom’.
Phil
I’m hoping this is not a sanyo battery characteristic, since many laptops i’ve had get hot while charging and half my collection are sanyo batteries.
indeed, one of the Thorfire review lights i got came with a Eachine cell, i have not even tried it in a light, i was thinking of capacity testing it then tossing it.
very interesting, i guess i had an irrational theory that they count mA one by one (like removing jellybeans from a jar and counting them )
Indeed, its just disconcerting to have 4 batteries from 3 lights all present as bad suddenly starting on the day the new charger is tested.