Thanks so much for another detailed review! Frontpage’d and Sticky’d.
Thanks, HKJ. I stopped buying these long ago and am glad for that. I still use a few of them when they actually work. Some of my lights (like Balder BD-2) will not even function on high using these cells. They should come with a big Avoid label on them.
i just did a rundown test on a pair i bought off amazon a little over 1/2 year ago, put em in my bc40, till the light shut off. when i measured them, one was 3.4v, the other had the protection tripped :bigsmile: , went under 2.8, great batteries they are, needless to say i am going to get some good cells soon and retire them asap
Bid at an auction on ebay and won four of these for ridicilous money and 1 is a complete dud, it doesnt work. Multimeter says 3,8v but it can only produce a dimly glowing LED (what you call halo?) that you can look straight into. Charging it with my WP2 II produced the interesting effect of voltage dropping the more I charged it. Put it in the WF-188 and it made it happier (but maxed out at 3,85). I dropped one on the floor when I unpacked them, don’t know if it’s that particular battery though.
The rest charges to 4,10-4,15v and two of them works OK, one flickers in my HD2010 on high.
Conclusion: If you pay less for four 18650’s and shipping costs from China than you do for a coffee at 7-Eleven, chances are the cells aren’t very good. But I didnt expect anything else. And two of them work just fine (for now).
I have 4 of these of the DX kind. So they are rated 2000mah? not bad considering the unprotected ones I have are rated at 850mah.
I made some discharge test with the cheap “Ultrafire” 18650 “3000” mAh batteries I have.
Since I can’t discharge these to 2.8V but only to 3.0V (1A), can I determine the full capacity of the battery?
The results of the discharge to 3.0V 1A, was around 1200 mAh.
That depends on the battery. Some batteries can easily be discharge above 3 volts, some other cannot. Look at the curve, if it is nearly vertical at the end, the battery is fully discharged.
In my test the batteries are not always fully discharged, especially not at 5A current.
I have an original imax B6 charger, I can’t export the results.
According to the battery life in flashlight usage, it must be around 2000 mAh.
Not bad for a “3000 mAh” cell???
iMax B6 can discharge down to 2.8V (or any other voltage, really) in NiMH mode.
Didn’t know that, I will try to 2.8V.
Safe for Li-ion?
Can anyone confirm that it is safe for li-ion too?
You won't get much capacity left discharging from 3V to 2.8V. I'd say your test is quite accurate. I only get 900mAh on mine.
But it is normally ok to go down to 2.7V, because even then at rest the voltage will bounce back to 3.3V or so after some minutes.
And the reason why you're "feeling" it has 2000mAh, is probably because in real life use, the current actually keeps dropping following the battery voltage (assuming normal linear driver).
A discharge test will keep pulling 1A regardless the voltage drop, until the battery drops below the preset target voltage.
How can you tell the difference between the UF 3000 "protected" and non protected cells? I purchased a headlamp that came with two UF 3000s that (surprise, surprise) seem to have significantly different charge times. The batteries are used in a parallel configuration. I am guessing that this will also translate to a significant difference in capacity. I am trying to figure out what I want to do with them:
1. Recycle them? They are brand new and that seems like a waste.
2. Buy 2 pairs of Panny 3400s and just use these if I forget to charge the unused Pannys.
3. Buy 1 pair of Panny 3400s and rotate these with the Pannys.
1. Those cells usually are waste.. ;)
Protected cells usually have a bump at the lower end like so:
I would get rid of all Ultrafire cells and get some decent ones. Which ones depends on your light.
They claim to be "protected" and they are longer than 65 mm. I held my calipers parallel to the button (but not contacting it - I don't want to risk shorting them). It appears to be about 69 mm long. That appears to match w/the FastTech specs for the protected cell. It looks like the Panny NCR18650B Protected cells are a physical match. I'm going to get a couple of pairs of those, a Nitecore charger, and maybe something to do controlled discharges on.
Again: those Panasonic cells might not be the best choice for your application.
The Panasonic cells are a physical match, high capacity, and are well reviewed. Am I missing something?
Yes, their discharge curve is flatter than some other cells, so they probably wont last as long/provide as much light as some other cells might. Of course, great cells, but not the perfect choice for any condition.
What cell do you recommend? I am new to this. Even though I have purchased the Pannys, I would be more than willing to have another matched set ...