Another IMR question

I have found different answers to similar questions, but I need to make this clear:

I am not supposed to discharge my Nitecore IMR 18350 lower than 2.75 V. Does that mean I have to check the voltage everytime I am to use my MT10C flashlight?

If I would let it drop below 2.75 V, what would happen? Explosion? Or just battery failure? Should I throw it away if it happens?

when a liIon cell is discharged too low, the lithium in solution begins to plate one electrode as Li metal. On recharging, this metal can catch fire and the cell can potentially vent with flames. What will likely happen is that you'll loose capacity but the potential for fire is there.

No light in space said:

I have found different answers to similar questions, but I need to make this clear:

I am not supposed to discharge my Nitecore IMR 18350 lower than 2.75 V. Does that mean I have to check the voltage everytime I am to use my MT10C flashlight?

If I would let it drop below 2.75 V, what would happen? Explosion? Or just battery failure? Should I throw it away if it happens?

Click to expand...

If you're playing with li-ion lights and cells, you should have a voltage meter to check things with and you should spend some time playing with your lights and doing informal runtime tests, to get an idea.

Lots of current lights will step down from High to med., or med. to low, or even start blinking, when the cell gets down below point X, Y or Z. That's our cue to remove the cell and charge it back up.

The key with over discharging a cell, down around that 2.5v/2.75v range, is to charge it (them) back up quickly. You might knock a few cycles off the life of the cell, but you won't have a 'ka-boom' problem to worry about if you charge it/them back up within a day or two. Letting them sit at 2.00v for weeks, probably isn't a good idea.

Chris

Many flashlights in this category have over discharge protection built in to their circuits which would prevent the light from activating before you reached a dangerously low voltage on the battery. On this model however, I see that it accepts primaries as well so I don't know how it would distinguish a very drained Li Ion cell from a fresh primary. That said, I can't imagine there is much energy left in a primary beyond 2.75 volts so perhaps the over discharge protection just kicks in right around there. I know that there are other lights on the market (such as the Zebralight SC32) that can handle both primaries and rechargeable cells and advertise over discharge protection so it must be possible.

No light in space said:

If I would let it drop below 2.75 V, what would happen? Explosion? Or just battery failure? Should I throw it away if it happens?

Click to expand...

I don't know. I use protected batteries in protected flashlights whose batteries are being charged in protected battery chargers. It's amazing how ignorant one can be and not have to worry about blowing themselves up. And then again, one day I might get lucky.

I've had protected batteries go bad too. There are jo guarantees. IMR is generally considered safer than icr however I recharge at 3.7 volts. If it went below 3 I'd throw it out. I'm more careful than most

recDNA said:

I've had protected batteries go bad too.

Click to expand...

Have you had protected batteries blow up on you or simply burn out? As you wrote, there's no guarantees against a battery burning out.

I'm more careful than most

Click to expand...

I'm less careful than most.

lol PQ!
I like protected too, takes the huh out of it.
Blissful ignorance ☺

Parrot Quack said:

Have you had protected batteries blow up on you or simply burn out? As you wrote, there's no guarantees against a battery burning out.



I'm less careful than most.

Click to expand...

Never had flame but have had batteries getting hotter even after removed from flashlight. Short circuit? Anyway buried in sand they never caught fire but got real hot. On both occasions they were protected icr. One was xxxfire so that may he par for the course. The other was a quality brand. Mostly just an inconvenience (burying them) and scary (afraid it would vent but I don't think they did). Point is protection circuit should have shut them down before they got so hot.

My understanding is imr less likely to catch fire but battery thread has experts. I know nothing. I have had good luck with AW batteries.

IMR often called "safe chemistry". I don'tknow why.

WarRaven said:

..............., takes the huh out of it.

Click to expand...

............................:thumbsup:

recDNA said:

I know nothing.

Click to expand...

Why that's right up there with how much I know.

I am sure the light will either warn you or even switch off before 2.75v. Around 3-3.1v the light probably wont even power on........not sure on that actual light!

Once cells are down to 3.6-3.8v give/take when used in a higher mode ,the voltage sag drops the voltage and it wont sustain turbo mode or even high mode in some cases(dependent on what light/output. This is a good indicator itself to either use lowest mode if in an emergency with no spares till you get home,or simply put the cell on charge and top back up to 4.2v.

A good way with a new light is to learn the run times, try running it on a specific mode and chack the V periodically,say every 10 or 15mins. This way you build up a rough picture of run time. You may find it will run for 1.5hrs before the cell is 3.6v(just an example here). So you can soon learn to top the cells off after X amount of use. If used for say 30 mins a day,simply top the cells off back to 4.2v for the next day,or top up every two days.......what ever works best. I like to be ready to go,so top my cells up for my next use........well if its been used for at least 20 mins or so. If i use it for a few mins i wont top off then
MM as Chris suggested is a great idea to keep an eye on cells,no need to do it daily,but again periodically. This will tell you of charger or cell issues and prevent any potential mishaps or simply being left in the dark!!

Recently I've read of a new user that put to use a new cell out of package, to the point of higher levels wouldn't kick in.
Thoughts were, possibly defective cell or light.

IMO, there can never be enough protection for those that don't follow this hobby fairly well, or loosely. Even if it's just a slightly minutely reduced life of cell in that case.
Not only protect home an limb, but wallet too. ☺

The cells are tougher than thought and will take abuse(not recommended of course) . I have charged a 4.2v cell up on the 3.8v setting to over 4.3v.......perfectly fine(as long as i dont keep doing it!!!)

Same with discharge, as said if it drops bellow the limit,carefully re-charge and test the cell,see if it holds charge...........chances are it will be fine. If it does not hold charge then re-cycle if less than say 4.1/4.15v(if it matters to you,even a cell holding 90% charge has good uses).

The odd discharge bellow spec or over charge is nothing to what these cells are tested to, but they end up dead after destruction tests......

Easiest policy is common sense,if anyone who can not use basic practices then imho should avoid the chemistry ...........
Little research is all it takes imo, 5 mins of reading,not sure just ask and experts will help/advise ......

Frightening how many i have had to educate at work using fire cells and fire chargers,leaving them on over night............:shakehead Quite frustrating tbh, i took the time to ask and re-search.......
If you cant drive a car without hitting curbs and catching other cars..........dont drive!!!

Many great minds park by brail!!!!!

I'm a class one licensed driver, I completely agree.

:thumbsup:

This not only enlightened the OP but majority of those who will be reading this thread as well... :thumbsup:

recDNA said:

Never had flame but have had batteries getting hotter even after removed from flashlight. Short circuit? Anyway buried in sand they never caught fire but got real hot. On both occasions they were protected icr. One was xxxfire so that may he par for the course. The other was a quality brand. Mostly just an inconvenience (burying them) and scary (afraid it would vent but I don't think they did). Point is protection circuit should have shut them down before they got so hot.

My understanding is imr less likely to catch fire but battery thread has experts. I know nothing. I have had good luck with AW batteries.

IMR often called "safe chemistry". I don'tknow why.

Click to expand...

It's because this chemistry is less likely to go into thermal runaway which is why IMRs are typically offered without a protection circuit.

No light in space said:

I have found different answers to similar questions, but I need to make this clear:

I am not supposed to discharge my Nitecore IMR 18350 lower than 2.75 V. Does that mean I have to check the voltage everytime I am to use my MT10C flashlight?

If I would let it drop below 2.75 V, what would happen? Explosion? Or just battery failure? Should I throw it away if it happens?

Click to expand...

MT10C pretty much the EC11 w/ tail clicky. single-cr123a so gotta be buck/boost driver

i left an EC11 tailstanding for a few hours. was very dim when i retrieved it. battery was a bit below 2 volts

problem is EC11 doesn't take protected 18350

so yeah have to babysit the EC11 LOL

So....is my Digicharger an adequate voltage tester? (as it displays the volts when a cell is placed in it). Or should I buy a specific tester?

Or not even bother and change the cells every night?