A warning Ultra-fire 18500, from a newbe

[wirehair]

I have written on here about the problems I am having with my Olight M30 and 4 Ultra-fire 18500 batteries I brought off Battery Junction. When the batteries were fully charged and run in the light they were draining at differant rates, ie when the light stoped 1 cell would read 3 volts and the other would read 00 volts. From information I have got off this site I beleave this is VERY DANGEROUS, and could lead to an explosion.
I have been in contact with Battery Junction about this many times and the only thing they were concerned about is sticking to their policy of having to return any faulty goods before they would look at replaceing them. Because I live in New Zealand I told them it would cost more than the product was worth to send them back! As you can see by my number of posts I am NEW to this site ( this was my first real light brought because of reading this forum). What I am realy CONCERNED about is at NO time did Battery Junction tell me not to recharge or use the batteries that they sent me and I think this was wrong. So if like me you dont know a lot about this sort of thing but think something is wrong, PLEASE bin the batteries as I have,:thumbsdow its not worth losing your sight over or worse.

 

[45/70]

When the batteries were fully charged and run in the light they were draining at differant rates, ie when the light stoped 1 cell would read 3 volts and the other would read 00 volts.

Sounds normal to me. It sounds to me like you haven't done enough research on Li-Ion use. Have you read the relevant threads in the "stickies" at the top of this Forum?

I'm not trying to sound like a Richard Cranium here. I just think maybe you need to do a little more research. When you drain Li-Ion cells down really low, the protection circuit in one cell, is bound to cut out before the others. This of course will give that particular cell a zero Volt reading. It's not good to run Li-Ion cells that low (less than 3.5 Volts), as a habit. It reduces cycle life appreciably.

Dave

 

[wirehair]

Hi there, the other trouble I was having with them is they were comming of the charger at differant voltage, some 4.1 and others at 3.8. If I put the low voltage ones back on to charge the voltage would drop! The other reason I was concerned there was something wrong is it was only running the Olight M30 for approx 25 min when it should be going for about 1 hour.
If there is something I am doing wrong please tell me as I know I have a lot to learn. Thanks. Greg.

 

[Kestrel]

they were comming of the charger at differant voltage, some 4.1 and others at 3.8.

What charger are you using? Some chargers have a better reputation for consistency than others.

 

[wirehair]

WF 139 Ultra-Fire, So is it alright to recharge and use these batteries, even if they recharge unevenly and seem to go flat way to quickly or do you think there may be a problem with them.:shrug:

 

[Black Rose]

Are you running 18500 cells in pairs with the extension tube, or individually?

If in pairs, you need match your cells by voltage, so they (hopefully) discharge at similar rates.

If individually, you are only feeding 3.7-4.2v to a driver expecting 9+ volts.

The best piece of advise at this point is to spend the money and get some AW 18500 cells. They cost more, but they are very high quality cells.

If you are using the extension tube, get some 18650 cells.

 

[45/70]

Well Greg, I hate to be the bearer of bad news, but the WF-139 doesn't have a very good reputation here on CPF. Some seem to work fine and others have all sorts of problems. It sounds like yours is one of the later. Your cells should all come off the charger relatively close to the same voltage (ideally 4.20 Volts) when the charger indicates they're done. If the cells are bad, the voltage will drop shortly thereafter. If the voltage drops to less than 4.00 Volts (80%) in 24 hrs or less, your cells need to be replaced.

That brings us to another potential problem. :sigh: UltraFire Li-Ion cells have the same reputation as their chargers. Some are fine and some are not. It really sounds like your problem is your charger though. If it can't charge them up properly, then it's difficult to say whether or not the cells are OK. Again, I'm betting you have a charger problem.

Dave