The Ultrafire and Trustfire cells are close to 3 years old ... And looks like the Trustfires are suffering ...
Updated with Ebay batt .. These generic ebay cells have been fantastic , these are the oldest RCR123A's I have [+ the first ] And still are holding there own .
Wow , some of my older cells have really de-graded ... I was beginning to wonder ...
This is a fantastic idea! It would be quite handy to have accurate data on different cells all in one place. For the funds issue, how about using paypal to accept donations for this project? Since I'd be benefiting from your work, I'd be more than happy to donate, and I think others would as well.
Just did some tests on my grey unprotected 14500 Trustfires. These claim 900mAh and may just have been able to provide that much once upon a time.
At a 500mA discharge to 3V I got 127mAh out of the best of them. The rest gave 4, 22, 37, 50 and 94mAh. Time I replaced those I think. I'll try giving them a very slow charge to see if they get any better.
Then I'll get rid of them.
Now trying some of the crap 18650 cells and my old RCR123s. Again, I suspect quite a lot of weeding will be in order, some of the RCRs will be 5 years old.
I think this is a good idea. old I have sent you a PM, let me know. I have some Solarforce protected 18650 and some Hi-Max 18650 on order now. based on preliminary reviews. I am a willing donor of new/used batteries :)
Got two of these this morning and have done some testing.
One of them reads 2.98v on the DMM, but will not charge at all. As soon as the charge cycle starts the voltage shoots way up and is then terminated.
The other one at least functions, I've run it through a charge/discharge cycle a couple of times without issue. Discharged at 0.5A it gave 546ma and 548ma which is consistent enough.
Obviously with a 50% failure it's hard to assess, but I wouldn't buy them again.
They were bought on eBay, mostly because they were terribly cheap...but as it turns out not a bargain.