Ok, at the start of the month I plumped on buying myself a possible work or around the home torch.
Had a look on eBay and picked up a 2 x 18650 ultrafire zoomy with an xm-l, 2 x ultrafire 18650’s (the bad ones obviously), and a charger. Total cost, 18 quid.
Delivery was quick (about a week) and the light is plenty bright enough on low for work and use as a night light when I feed the new born. I’m pretty happy with the light.
This morning before using it I decided to check the cells, good job really, their supposed to be protected but one has discharged to 2.93v on my avo dmm, the other to 2.12v.
Now, I fully expected to have to get decent cells and a more known charger, I’ll be using a guy over here that I got a decent xm-l bike light from that started all this, he has sennybor (sp?) 2800mah cells at a reasonable price and he does a lot of testing, his blog is torchy the battery boy.
My question is, do I flop the cells in the charger tonight and see what happens or just junk them as they pose a fire risk? Even if I only get one more charge out of them I’ll be happy but I don’t fancy risking a fire for the sake of waiting a week.
Thoughts please.
Ok, well I went for it and slapped the cells in the charger (zhen bo hzs-002, 4.2v 600mA) this charger has the fold out US pins, which seems to tickle a memory about being one to avoid.
I only have my cheap dmm available tonight, avo’s with my work tools on a job.
I plugged in at 6.00pm, the terminals read 3.83v on each cell. Just checked again (charging led still red) and they were reading 4.53v, removed the cells and they read 4.53v on each cell so I’m leaving them to rest. If they do another week’s duty then that’ll do, I’ll be ordering some decent cells and a reputable charger/ might have completed a deal with Vickers which includes a charger.
We shall see what the cells look like in an hour, it should be said, the meter is an ultra cheap one, just bought to live in the tool chest of my off roader so may read high, its just all I have.
Charger is luke warm at the business end, cells are cool, so I’m not immediately worried yet. It may be good yet.
Wait, your 18650s are 4.53 volts? Do not use those. Those are grossly overcharged. You need a new charger and batteries.
+1
Get this:
Or at least this:
RC 1S-6S Lipo Battery Voltage Indicator Checker Tester 2.8V -25.2V
If you plan on safely using Li-Ions either of those is a minimum to have.
Also, 18650s charged to 4.53V sound rather frightening. I'd be very careful around those.
Viktor
I’d pretty much already decided to replace both tbh, after an hour they had settled to 4.23v/cell, again on the cheap meter, I’ll check them tomorrow on the avo to see both what they settled to over night and I’ll compare the two so I have a better idea how different they read.
Incase you’ve not heard of them, I would say avo is flukes daddy, they have been going a long long time, I have one of their vintage dial meters too, probably circa 1960 or earlier, my avo digital meter has been a trusted friend for a long time.
Thanks for the input guys, like I say, the cells are the not to be trusted ultrafires, and came off eBay, so I’m hardly suprised they are questionable but they are not hot, and a quick test of the torch after re checking the voltage completely failed to turn it into a pipe bomb (bargain).
I’ll be ordering some senybor 2800mah cells and a reputable charger at payday, or I need to get some carriers to use my li-ion hobby charger which is definitely more trust worthy than any of the simple chargers the Chinese ship 8)
Just got back to work, so I did a quick comparison on the cells between the two meters.
Avo - 4.03v for each cell
Cheap dmm - 4.33v for each cell.
So going off that the 4.5v would be more like 4.2v, although I’ll do some more cross comparisons as the torch is used, its too usefull as a night light when baby wakes not to use it, and I’m feeling fine about things for now.
Funnily enough the cheap meter I have is identical to the one linked above, although the case is yellow and branded “laser”, which is a cheap brand of tools available over here.
I’ll stick to my avo till I have done enough testing to correct the cheap meters readings, and given that the charger didn’t get hot, do some more testing of that purely for interests sake. 8)