I wanted to full discharge my AAA Tronik (LIDL brand) Ni-MH battery.
So I put tham in my Lumnitop pen and left working on high.
When light get hot I stoped and leave to cool for some thime. After that I start discharge again. After 4 cycle I coud not swich it of. First though was swhitch is broken but when unscrew battery tube a gas star blowing out.
Obviously gas preasure was blocked the switch.
Has anyone had similar problem with Ni-Mh battery and should I expect problem with more powerfull 4xAA light such as Thrunite TN4HI and Nitecore EA41?
I’m not the expert, but I’ve never had one vent like that. I would think it got too hot. Probably damaged? Let the experts chime in tho.
If only one vented, that one may have had a lesser charge to begin with and got stressed as the others voltages dropped.
according to eagle tac, Yes
“NiMH rechargeable battery may release gas during discharge. If you experience an inflated switch boot or find high pressure being built inside the flashlight, switch off the flashlight immediately. Slowly loosen the tail-cap to reduce the internal pressure and replace all batteries.”
darksucks says Yes about Alkalines:
“alkaline batteries can release gas during discharge”
> I put tham in my Lumnitop pen and left working on high.
> When light get hot I stoped and leave to cool
> After 4 cycle I coud not swich it of
dont do that!
glad nobody got hurt
sounds like running the light on high until it gets hot, 4 times in a row, definitely is not a wise way to discharge the batteries… btw, NiMH does not need to be fully discharge cycled afaik, that was a NiCad thing…. but if you do want to cycle your batteries, I suggest you not use high, or any mode that gets the light hot :-)… note, it is not very good for NiMh to be overdischarged, so dont turn it on until it dies, repeatedly after resting, on any mode.
Yes they can.
Why were you doing that?
Yes it happened to me in my nitecore ea41. But it was my fault. I had bought 8 imedion cells. About 15-20 cycles in one refused to charge on my opus so I was moving it to a smart dumb charger once it started there it would charge in the opus. Well about 9-10x of force charging. I put it in my ea41 battery rotation and turned the light on low. Cold light cool batteries. About 15secobds on low I heard a hiss and the switch boot swelled up like a balloon. It went back down but yes they can vent. If a good charger refuses to charge them. Just put it in a recycle bin
Absolutely NiMH can vent. It doesn’t vent as toxic / flamable chemicals as lithium based chemistries however… but they most definitely can vent.
I was reading some information on NiMh venting and most reference sources mention dangerously OVER charging as the cause of venting……
But the OP was discharging the batteries :question:
yes, I agree the links are about charging, at least the part I looked at briefly, like you
BUT, they vent during DIScharge also
Because there was 2 battery in series it is possible on of them to discharge before other one and become load instead source.
I am not going to use Tronic battery any more.
Tronic nimh battery`s say they are Gas-proof on the back of the packaging.
John.
I once tried a 2xAA setup with a DX 7880 driver to drive an XM-L2 T6
Both alkalines get super hot and vented, tearing my tailcap boot as well as melting my switch.
Stupid mistake for me to drive a single AA driver with 2xAA but yes Alkalines do vent
But this is about Nimh so I guess my comment was irrelevant
Well there are vent holes in the positive nipple of an nihm battery, I suppose these are to release pressure in an emergency situation, But normally they don't release gas.
Lithium single use cells, CR123A and alike have the strange smell when you open a sealed container, that smell has been named flashaholl, so these must not be gas proof.
John.