10440 became dangerous?

[PANGES]

I'm not sure what happened, but I tried to turn on my ITP A3 EOS upgraded today, and it would only go to low and medium, but not high. Last time I checked the UltraFire 10440 (several days ago), it was at 3.1V. After turning it off and on several times, I still couldn't get it to go to high, and when it was supposed to go high, it flickered a little bit then went down to low. Made me really nervous so I took the battery out and hooked it up to my cottonpickers charger to check the voltage, and it wasn't displaying anything. I had an extra UltraFire 10440, so i put that to the charger and it was reading 4.0V, so it's not the charger's display that's not working. I stuck the new 10440 in and the light functions correctly.

Just to be safe, I wrapped up the old battery and put it away in a box for now, as I don't want to risk it blowing up on me. Can anyone tell me what might have gone wrong with the battery? I'm careful to never overcharger or overdischarge the battery, and the battery has only been through 2 cycles (it's currently on its 3rd cycle.)

 

[VidPro]

its a 10440, they are not very robust items. the use of them in 1.5V intended lights runs them rather hard, i have never seen one with added curcuit protection. and might or not have PTC thing and usually have venting capability.

Last time you checked it was at 3.1V, and you did not recharge it?? because it was basically low then, and indicated by it not working under the high load.

A better longer term battery for slightly higher output, without overdrive, would be to use a AAA 1.5V type (1.7V) lithium primary cell item.

There are slightly better 10440s but they all can only handle so much, and because of how we will end up using them, and the lack of protection, they will not last very long.
The user has to re-charge them as soon as they get low, and because they are driven hard in a situation like this, and have minimal capacity, they get low fast, and have to be recharged.

It doesnt have enough power or juice to really reek havoc, but if it is not protected (they usually are not) and it is at 0V, and you cant get it to charge, then it would be best to get it out of your house, away from humans, where it cant burn anything (unlikly).

if it unsealed, or vented, then you dont want to be breathing that.

 

[PANGES]

The last time I asked about when to charge a 10440, I was told to charge it when it gets between 2.4-2.7V. Was I misinformed, or did I misread something? =/

 

[hellokitty[hk]]

Yeah maybe you should go back and reread until you fully understand.
2.4 - 2.7 resting is pretty low. 3.1 is actually pretty low too.

 

[PANGES]

Around what range should I recharge a 10440? I don't want to mess up the one I'm using now, because it's the last one I have.

 

[VidPro]

They are speced for as low as 2.5v . A big one can be depleated when it is at ~3.5 rested. Under a load even a big one will drop down fast in voltage when it gets mostly depleated. After resting they will float back up in voltage some.

Because in this little high resitance battery it will droop a lot, under a load it indeed might drop to ~2.5V, so if you had a cutout point under load, it could be around there still. Rested, if it is showing below ~3.3V though you should charge it back up again.
It is basically when the cell doesnt output much power, so when it starts to dim in output, or doesnt make the high level.


Again because it is a boost curcuit drive, you wont be able to easily see when it needs a recharge as easily, it could still run at a voltage that would damage the battery. I always ended up charging it very frequently. eventually i got tired of trying to get such a small battery doing bright light, and moved up to bigger.

if its the Last one, probably should get another one.

 

[AnAppleSnail]

3.1v resting is nearly empty. Maybe you've got 20% capacity left. Go ahead and recharge when you catch it here.

 

[PANGES]

Eek! Thanks for the info, guys. I'll keep a closer eye on my batteries and charge them more frequently. For now, I think I'll throw away the one that wont even display a voltage. So, for a 4.2V battery, I should charge around 3.5V when rested. I'm thinking of switching to a CR123 light, and will begin using 3V 16340's... I'm guessing I should charge those around 2.5V?