Pila/U2 Problem, please help!

I have a U2 about 6 months old that I use a Pila 600p rechargeable battery in.

(on a side note, I bought 2 of these batteries and one of them never worked. I tried bending the spring out a little to make sure it was getting contact, and it never worked...what a waste of money that battery was, but maybe it wasn't the battery?)

Anyway, up until today my flashlight worked perfect. I'd use it, it was great, I'd recharge, everything was fine. Then today it just stopped working. I tested the volts on the battery and I get about 4.1 volts I think. I tried CR123s or whatever the battery is that the flashlight came with originally, and they worked...so, it doesn't seem to me like it's the flashlight itself. Does anyone have any ideas? Again, nothing changed with the light. I didn't take it apart and then it stopped working or anything like that.

Please help! THANKS!

It's possible that the positive contact spring of the U2 isn't connecting with the positive contact of the battery anymore. I wouldn't recommend stretching the spring on the U2. I would suggest adding some solder to the positive contact point of the battery itself in order to bridge the gap between contact point and spring.

I dont know, I guess it's possible but it seems unlikely, because the thing worked fine for months, and then suddenly stopped? I don't get it...

grnamin is most likely correct. It is possible due to wear on the positive contact spring and the battery. I had to stretch my positive spring quite a bit until the 18650 battery worked for me(similiar battery). The other possibility is to make sure the 3-4 tabs on the tailcap are raised high enough to make contact to the body, since the Pila battery might be slightly longer than 2 CR123 batteries.

chetwynd said:

I dont know, I guess it's possible but it seems unlikely, because the thing worked fine for months, and then suddenly stopped? I don't get it...

Click to expand...

tried everything. 2 CR123s work, voltage reads 4+ on the tester. what the hell could be the problem here? is there something else i should be testing the battery for? could there be voltage but no current?

You are positive that the tabs on the tailcap is raised high enough to contact the body? The 2 main problems has always been in the tailcap & the positive spring. I had to modify 2 of my U2's to work with 18650's. Most people think the positive spring and/or the tabs on making contact but they are not. Be patient and triple check these 2 areas carefully.

chetwynd said:

tried everything. 2 CR123s work, voltage reads 4+ on the tester. what the hell could be the problem here? is there something else i should be testing the battery for? could there be voltage but no current?

Click to expand...

Yep, just tested with black ink...they're both making contact. Weird huh?

Any other ideas?

Do you have any other 18650 or 17670 batteries charged that you can try?

chetwynd said:

Yep, just tested with black ink...they're both making contact. Weird huh?

Any other ideas?

Click to expand...

I'm somewhat of a rookie...I don't even know what those are! But no, I only have 2 CR123s that work fine in the light, and the rechargeable battery I've always used.

Are you putting the black ink on the body to check the contact with the tabs on the tailcap? Double check the actual tailcap spring is long enough make make proper contact.

chetwynd said:

Yep, just tested with black ink...they're both making contact. Weird huh?

Any other ideas?

Click to expand...

I know this must be frustrating to troubleshoot, but imagine being in my shoes.

Yep, the tail spring is definitely making contact. I can see the scratches on the battery from the spring.

I'm a pretty handy guy so there's nothing that appears to no longer be making contact.

Are volts the only thing I should be testing for with my battery?

Did you actually mark the body to verify the tabs on the tailcap are making contact? I like challenges, so it's not frustrating. It's more frustrating when nobody helps you...that's why you are a fellow CPF'er

chetwynd said:

I know this must be frustrating to troubleshoot, but imagine being in my shoes.

Yep, the tail spring is definitely making contact. I can see the scratches on the battery from the spring.

I'm a pretty handy guy so there's nothing that appears to no longer be making contact.

Are volts the only thing I should be testing for with my battery?

Click to expand...

Yep sorry, forgot to mention that I did that too. I marked the top and bottom spring, the 4 little tabs. Everything is getting contact as far as I can tell. This is so annoying!

I say it is the batteries. Do you have 2 batteries?

chetwynd said:

Yep sorry, forgot to mention that I did that too. I marked the top and bottom spring, the 4 little tabs. Everything is getting contact as far as I can tell. This is so annoying!

Click to expand...

Can you check the voltage from the tail of the battery to the side of the flashlight where the tabs contact and confirm that there is potential between the light and battery? Also just get a small magnet put it on the positive cap and try that. (cr123's are about 3mm so their are 5 extra mm that the tailcap spring has to make up for, so a megnet shouldn't cause binding either.

I bought batteries from these 3 places, I actually like the LG batteries from www.batteryjunction.com and www.batteryspace.com a little more since they have a higher capacity, but unprotected which I never had a problem with. http://candlepowerforums.com/vb/showthread.php?t=140362
http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=2763
http://www.batteryjunction.com/li18cyce326h.html

Use caution when using a magnet, because you can cause a short and the battery can explode. I have not tried this, but I have read many cautions. Your choice.

65535 said:

Can you check the voltage from the tail of the battery to the side of the flashlight where the tabs contact and confirm that there is potential between the light and battery? Also just get a small magnet put it on the positive cap and try that. (cr123's are about 3mm so their are 5 extra mm that the tailcap spring has to make up for, so a megnet shouldn't cause binding either.

Click to expand...

Ya I should also mention that you should test contact with a MM like you would for the first test if you get a full 4.2 volts then you are shorting so reposition the magnet, it should give you slightly less due to resistance.

I don't know about this magnet thing. I can take a measurement with my meter, but where did you want me to check it? I read what you wrote but I didn't totally follow. thank you!

Put a battery in yoru U2 without a tailcap and check the voltage between the batteries - and the side of the body.