UltraFire 18650 question:

I recently purchased a laser from FocalPrice which I'll review later, however I'm having issues and I suspect it's the battery itself.

The battery came with the laser, though I can't tell if it's charged. (I'm at work, my multimeter is at home)

It DID come with a charger, and when I connect the charger and battery, the light goes green on the charger.

My assumption is that this indicates that the battery is fully charged.

My question:
What indications do you have that a battery isn't charged other than the intended product isn't working? I don't want to over-discharge the battery, though I think the battery itself has a protected circuit in it. I don't know though. It's a blue UltraFire battery, and it does have the little bump on the positive side, though that may not mean anything. I've never used these types of batteries before so I'm not sure.

Any ideas/suggestions on what I can do? Worst case scenario, I'll just wait until I get home and check with my multimeter but wanted to get your opinions

Thanks

Is the light on the charger red or green or not on before you put the battery in it?

Ooh, good question:

The charger light is green without a battery in, however when I put this battery in that seems to be acting like it's dead, the light remains green.

Also, just a quick side question: How would I be able to tell if a battery is protected or not?

Thanks for your quick response!

I have three Ultrafire branded chargers that all show a green light without a battery inserted, blinks red/green while charging and solid green when charged. Without knowing its voltage I would assume as long as you're putting the battery in the charger right that it's fully charged.

Make sure the 18650 cell is making good contact at both ends. If that doesn't work it could be either the charger or the battery. I have seen both 18650's and chargers from cheap china sites that are bad. You will have to take a guess as to which is bad an obtain a replacement or replace both of them!

Protected cells are a bit longer than unprotected. exact measurements escape me atm.

To find out if the battery is protected or un-protected. Here's a

suggestion. Just do a little reading of the writing printed on the

battery. It should probably let you know if the battery is

protected/unprotected !

202bigmike said:

To find out if the battery is protected or un-protected. Here's a

suggestion. Just do a little reading of the writing printed on the

battery. It should probably let you know if the battery is

protected/unprotected !

Click to expand...

While your assumingly sarcastic remark hasn't gone unnoticed, most batteries don't actually say either way. I've been doing more than enough research to justify asking the question as to the telltale signs of a protected battery and so far there has been no conclusive reply with the exception of an increased length of the cell by roughly 2-3 mm.

Some batteries do indeed say, but there are many that don't say either way regardless of the presence of the protected chips or not.

A protected cell will have a circuit board on the negative end. You will see an indentation that goes around the circumference of the cell on that end, where there is a gap between the circuit board and the negative end of the cell.

coherent light said:

Protected cells are a bit longer than unprotected. exact measurements escape me atm.
[\quote]

Yep, that's true. I think it should be about the thickness of a circuit board + thickness of tiny surface-mount chips. Probably around 3-4mm

It could be that the battery was DOA. Another possibility is that the protection circuit was tripped. Sometimes these can be reset, but you may need a "dumb charger."

Click to expand...

Yeah, after more research, the stupid battery was dead, but I found out only after taking apart the laser trying to fix it lol

Needless to say, I'm not risking anything with a battery like that. If it doesn't work, I'm just going to recycle it. No reason to mess around with it.