Test/Review of Keeppower 18650 3100mAh (Black)

[zenbeam]

Got my 2 pair of Keeppowers a few days ago and finally had time to complete the top off charge on one pair today. I don't recall my first volt reading, but I want to say they were at 3.68v upon arrival. I've only topped off one pair so far using an Xtar WP2 II. I had to interrupt the charge 2 or 3 times due to limited time and the need to snooze, etc. But I did check the voltage of the pair before resuming the charge each time and they were impressively exactly the same voltage as one another each time.

When one battery completed the charge, the other was about 30 seconds behind when it completed. *They both read at 4.22v. I was a little surprised that they actually went over 4.2 at all, but if I understand it correctly, a +/- .05v is still safe. And these are the first 3100mAh batteries I've had and figured it was due in part to their larger capacity. This was also the first time I used the Xtar WPA2 II charger on any 18650's - just bought it very recently. I used it to top off a 14500 and it reached 4.18v when the light turned green.

I tried them out in my Crelant 7G5 V2 and man they performed just fine initially. I still opted to remove them from the light for tonight and then run a bit more juice out of them tomorrow and leave them in.

Initial impressions - great price, the labeling and shrink wrap is very professional in appearance, they arrived in about 12 days from China... not too shabby shipped to the U.S., and they didn't warm up during charge and they worked great in a long throw light.
EDIT: And two of them fit just fine in my Crelant 7G5 V2. Have yet to test out fit in my 1x 18650 lights.

*Only concern - should I be concerned about them being charged to 4.22v when the light turned green?

 

[Shadowww]

*Only concern - should I be concerned about them being charged to 4.22v when the light turned green?

You should be more worried about your DMM (or charger, in case your DMM is calibrated/tested against some known reference), not the batteries themselves.

 

[zenbeam]

Thanks Shadowww. It's a cheap DMM - so far I think things are in the realm of proper behavior, but I do keep a close eye out for any irregularities.

I charged up the other pair today. They were at 3.62v out of the wrapping they came in (the others were probably at that too, I just didn't make particular note when I checked the first pair). I was able to top them off today uninterrupted on the Xtar WP2 II. When the lights turned green the batteries both measured at 4.21v right off the charger.

This time I tested for fit in my ZL SC600 and Romisen RC-T601 II - no problem with fit what so ever. I haven't tried one yet in my Fenix TK21, but I about half expect it may not fit into that light because there have been so many reports of Fenix "T" series lights not accommodating 3100mAh 18650's (not sure if that applies to "TK" series). But heck, I'm happy they fit 3 of my 18650 lights! When I get around to checking the fit the Fenix TK21 I'll note the results here just for completionist kicks.

 

[tobrien]

zenbeam, most 18650s i get based on those Panasonic 3100s come to me sitting at around 3.6v. i think that's how they leave the panasonic factory honestly.

my intl-outdoor ones came the same way and my orbtronics too

nothing to worry about

also the 4.2x volt reading you got straight off the charger 'chills out' and lowers after a bit. what you're seeing is perfectly normal

 

[zenbeam]

I like perfectly normal when dealing with these li-ions.

 

[tobrien]

my four just arrived today and i don't know if it's purely coincidental, but none of them had the label over the protection strip (as in, the strip that goes from end to end was not under the sticker/label on any of the four)

this is real nice. it's a small thing, but i was pleasantly surprised.

this should also maximize the fit on any lights i throw them in

 

[zenbeam]

I finally tried one of these for fit with my Fenix TK21 - perfect! Not the least bit of issue with fit on any of my 18650 lights. Nice!

@ tobrien -
I looked at mine after reading about your protection strip and it seems mine is covered by the label. That is if it's what I think it is. There is a little raised strip maybe 1/8" wide (if that) that runs fully lengthwise - under my label. Can you take a photo of yours?
Which way is it supposed to be anyway? I kind of assumed the label would cover everything?

 

[HKJ]

@ tobrien -
I looked at mine after reading about your protection strip and it seems mine is covered by the label. That is if it's what I think it is. There is a little raised strip maybe 1/8" wide (if that) that runs fully lengthwise - under my label. Can you take a photo of yours?
Which way is it supposed to be anyway? I kind of assumed the label would cover everything?

It does not really matter if the strip is under the label or on the opposite side, it will increase the thickness of the battery. It has to be just beside the label to reduce the impact on thickness.
You can see how the strip looks in my article about the battery construction.

 

[zenbeam]

It does not really matter if the strip is under the label or on the opposite side, it will increase the thickness of the battery. It has to be just beside the label to reduce the impact on thickness.
You can see how the strip looks in my article about the battery construction.

Okay - thanks. The "wire" is what I noticed then. So while it might be optimal to minimize battery thickness by having it beside the label, as long as there are no issues with fit otherwise, the function of the protection remains the same (under, beside or on top of the label)?

 

[HKJ]

Okay - thanks. The "wire" is what I noticed then. So while it might be optimal to minimize battery thickness by having it beside the label, as long as there are no issues with fit otherwise, the function of the protection remains the same (under, beside or on top of the label)?

Yes, the position only affects the thickness with maybe 0.1mm and does not have anything to do with the function of the protection circuit.

 

[tobrien]

I finally tried one of these for fit with my Fenix TK21 - perfect! Not the least bit of issue with fit on any of my 18650 lights. Nice!

@ tobrien -
I looked at mine after reading about your protection strip and it seems mine is covered by the label. That is if it's what I think it is. There is a little raised strip maybe 1/8" wide (if that) that runs fully lengthwise - under my label. Can you take a photo of yours?
Which way is it supposed to be anyway? I kind of assumed the label would cover everything?

yeah man, everything hkj said!

i guess mine was luck of the draw then. i know Redilast/EDC+ has stated they do theirs so that the label is never over the wire/strip. it's a nice touch.

 

[justanotherguy]

I just got 10 of these from the doingoutdoor seller on ebay I paid 85 But ended up having them send me a paypal invoice to get this price.
They just got here this evening and I dont think you can beat the price for a heck of a deal on good batteries.
Just fyi
Josh

So did you submit an offer, or send them a message negotiating this?? $8.50 a battery seems great!!
I am going to have to give this a try!!!

Tony

 

[tobrien]

So did you submit an offer, or send them a message negotiating this?? $8.50 a battery seems great!!
I am going to have to give this a try!!!

Tony

yeah you click the "Make Offer" button on the auction page and type whatever you want.

 

[justanotherguy]

yea, I sent an offer, we'll see what he says..I should have gotten someone else in and upped my order to 20 batteries....




edit: Offer Rejected

 

[justanotherguy]

offer accepted @$10 a cell , qty 10 though....

 

[veedo]

Offer accepted $40 for 2 pairs. $10 a cell, not too shabby.

 

[justanotherguy]

Offer accepted $40 for 2 pairs. $10 a cell, not too shabby.

Ditto! But he told me 5 pairs for $100...I really budgeted $80..but whats a few more cells? I guess I just have to buy another light or two to put them in!
These look like great values even compared to AW's.I am phasing out the UF's
Tony

 

[justanotherguy]

I am about to get the 10 in, but I figure I might have 2-4 left over, if there is anyone local to NE ILLinois who might want in @$10 each...
Tony

 

[veedo]

cells showed up yesterday, 9 days, impressed!

 

[hellokitty[hk]]

I am about to get the 10 in, but I figure I might have 2-4 left over, if there is anyone local to NE ILLinois who might want in @$10 each...
Tony

Why don't you try starting a group buy? I'm sure that people may be interested if you can get them at $8.50 a cell.