Bad 18650?

[jtivat]

I have some new UltraFire BRC 18650 3000 mAh cells. The cells read 3.98 and 3.99 volts. They will not light up any of my 18650 lights to full brightness while all my other 18650 cell work fine to even lower voltage. Is this the norm or could I have bad cells this is only after two charges.

Thanks

 

[kramer5150]

Thats a little low for a fully charged cell. The voltage is that low right off the charger?

How deep are you discharging them? I have run some 18650 cells in a resistor-direct drive XRE-DIY all the way down to visible dimming, and the cells were toast. After that they would not accept a charge higher than ~3.95V

 

[jtivat]

Thats a little low for a fully charged cell. The voltage is that low right off the charger?

How deep are you discharging them? I have run some 18650 cells in a resistor-direct drive XRE-DIY all the way down to visible dimming, and the cells were toast. After that they would not accept a charge higher than ~3.95V

Sorry no they charge to 4.2 they just quit working at 3.99 while my other cell work fine down past that voltage.

 

[kramer5150]

maybe the protection circuit is kicking in?... a little early?

I have to admit though I do not have much experience with protected 18650s.:thinking:

 

[Nil Einne]

Sorry this may be a dumb question but are you saying they're 3.99/3.98 when being driven or under no load?

 

[Black Rose]

It's possible that the protection circuit is kicking in and they are bouncing back to 3.99 when the load is removed and the circuit resets.

I believe the reviews indicated that the 3000 mAh Ultrafire 18650s don't do well at higher current draws due to higher internal resistance.

EDIT: Seems they do fine with 1A and under loads, but no so good with higher current loads.

 

[jtivat]

They will not charge past 4.1 volts now I think they are toast. I have used them three times now!

 

[Monocrom]

I have some new UltraFire BRC 18650 3000 mAh cells. The cells read 3.98 and 3.99 volts. They will not light up any of my 18650 lights to full brightness while all my other 18650 cell work fine to even lower voltage. Is this the norm or could I have bad cells this is only after two charges.

Thanks

Yup, very normal . . . For Ultrafire cells. (Speaking from experience.)

 

[jtivat]

Yup, very normal . . . For Ultrafire cells. (Speaking from experience.)

It is normal for them to be worthless after a few uses? These cells will not power up poop anymore and are trash!!!

 

[jasonck08]

I've not owned the cells you have, but I have had several Ultrafire cells go bad after 10-20 cycles. Think it may have been from deep discharging them. The IC doesn't always kick in at the proper 2.75v mark. Go down much further and you begin doing damage to the cell that is irreversible.

 

[Monocrom]

It is normal for them to be worthless after a few uses? . . .

Yes.

It's also normal for some of them not to charge up at all, or never charge up fully, or not work the very first time you use them, or not hold a charge for even a short amount. Every now & then you get lucky, and get Ultrafire cells that actually work properly.

Ultrafire cells are like the sanity level in a mental institution. Completely unpredictable and unreliable.

 

[march.brown]

I only use Ultrafire (18650) batteries ... I only have eight of them ... Two are unprotected (blue) and six are protected (grey) ... I think that they are great ... They are all 2400mAh ... Can't see any reason to buy any other make.

They do seem to get some good reviews though as with all makes , there can be baddies.

I am not in the Armed Services , the Police or the Armed Response Team so it isn't that important to me ... I do however carry an iTP A2 as EDC plus my two keyrings have iTP A3s attatched , so if my Ultrafire powered Solarforce dies I always have other means of providing light.
.

 

[jtivat]

Well does anyone know how to get a hold of Lighthound? I tried there contact e-mail on there web site and have not got a reply and it has been four days??? I would think they should do something about cells that only lasted two charges.

 

[jasonck08]

If you paid with Paypal file a claim with paypal, that will get their attention.