Ultrafire cells protected??

[Buck]

Are either these cells or this light protected from over-discharge, or is this thing just waiting to go ?

http://www.dealextreme.com/details.dx/sku.2978

Would you let your kid carry it?

 

[TOOCOOL]

Yes why not :shrug: its only a single cell flashlight not a grenade

 

[DM51]

Would you let your kid carry it?

No, I would NOT!

The light is a Fenix knockoff. It may be a piece of junk or it may work perfectly well - I don't know, perhaps someone else here has one and has reviewed it. That is not the problem.

The reason you should not give it to your child is because the cell is an unprotected one. There are no 10xxx protected Li-Ion cells in existence, because the cell diameter is too small to take a protection circuit. Maybe someone will come up with a 10mm-size circuit sometime soon, but such a thing does not yet exist AFAIK.

Unprotected cells in the wrong hands are dangerous – it is too easy to over-discharge them, and if that happens, any attempt to recharge them can result in venting with flame. Overcharging is another problem – some cheap chargers do not terminate properly at 4.2v and again, this can result in the cell blowing up. In fact there are all sorts of potential problems – for example, one could easily imagine a child thinking a 10440 was a regular AAA rechargeable cell and putting it on the wrong charger.

My advice would be not to give a child ANY light that needs a Li-Ion cell. Unprotected cells are just asking for trouble, but even a protection circuit is no proof against an accident happening. There are very good lights which take AA alkalines or NiMHs, and I suggest you choose one of those.

 

[TOOCOOL]

The question was, Would you let your kid carry it? not would you let your kid recharge it. Please explain how holding this light will make it go

 

[Eric242]

He already did: over-dicharge!

Eric

 

[Buck]

In fact there are all sorts of potential problems – for example, one could easily imagine a child thinking a 10440 was a regular AAA rechargeable cell and putting it on the wrong charger.

I'm kinda worried about ME doing that!

My advice would be not to give a child ANY light that needs a Li-Ion cell. Unprotected cells are just asking for trouble, but even a protection circuit is no proof against an accident happening. There are very good lights which take AA alkalines or NiMHs, and I suggest you choose one of those.

Not really planning on giving her a Li light, just a litmus test for idiot-proofness. She has a couple of lights with Barbie on them, :green: but at least I stuck a Teklite LED drop-in in one. They all have NiMH.