Lithium Batteries on Flashlights

[Ian2381]

There have been a craze on using Lithium powered Flashlights but is it safe to use Protected rechargeable batteries especially on actual usage since based on my understanding, it automatically shutoffs when drained to limits without dimming like ordinary rechargeable batteries do.

I have some protected rechargeable Lithium Batteries(14500, 10440, and 18650) but when in actual use I find it just for impressing people and still relying more on my AA/AAA powered lights.

Just a thought:shrug:

 

[Moonshadow]

it automatically shutoffs when drained to limits without dimming like ordinary rechargeable batteries do.

That depends on the light. Some fully-regulated lights have a fairly sharp cutoff, others go into direct drive so that the light output tails off and yet others (RA clicky for example) are designed to give you very clear warnings and switch to a lower level as the battery runs down.

 

[ampdude]

I think the biggest thing is to get to know your light and get a DMM, a cheap one is fine, so you can gauge when the batteries are getting too low by their voltage reading. This is not fool-proof with all lithium cells, but it is a good general indicator. I use lithium based lights almost exclusively. As the previous poster mentioned some lights will shut off at a certain voltage and some will drain the batteries down until the protection circuit kicks in. But if the light has a low drain off of the battery, it may not trigger the protection circuit properly, or it may not trigger at all if the circuit is faulty. I generally use IMR's these days which don't require a protection circuit so I just try not to run them below 2.5V because it is bad for them. And I usually don't run them that low unless necessary. I can usually tell when my lithium rechargeables are about to give up the ghost.

 

[Ian2381]

I tried runtime test on my Led Flashlights with Lithium cells (w/ protection circuit) and when drained at a certain level it just shuts off.
I would hate for this to happen in actual use.:candle:

Does the regulated lights have significant decrease in output before the protection circuit kicks in?

I'm confused with Lithium Cells(w/ protection circuit), Bought them for safety reasons and now I'm thinking If I should have gotten the one's without protection circuit.:thinking:

 

[Moonshadow]

The way to prevent that happening is to top 'em off regularly and, as ampdude says to get a voltmeter so that you can check the level of charge.

Does the regulated lights have significant decrease in output before the protection circuit kicks in?

I think I've already answered that - it depends on the light.

It would help if you could tell us which light you have, that way we might be able to give you some more specific advice.

I think it's also important to realise that there are different aspects of safety: a sudden loss of light might indeed be a problem in certain situations, but the protection circuits will protect you against other things, such as overdischarge, short circuit and venting (although a little bit of effort with the voltmeter and the charger is preferable to relying on the circuit). As with so many things in life, there are always tradeoffs.

You might want to pay a visit to the Flashlight Electronics - Batteries Included section: where there is a lot of useful information and very knowledgable people.

http://www.candlepowerforums.com/vb/forumdisplay.php?f=9

 

[Ian2381]

The way to prevent that happening is to top 'em off regularly and, as ampdude says to get a voltmeter so that you can check the level of charge.

I think I've already answered that - it depends on the light.

It would help if you could tell us which light you have, that way we might be able to give you some more specific advice.

I think it's also important to realise that there are different aspects of safety: a sudden loss of light might indeed be a problem in certain situations, but the protection circuits are designed to prevent other things, such as overdischarge, short circuit and venting. As with so many things in life, there are always tradeoffs .

You might want to pay a visit to the Flashlight Electronics - Batteries Included section: where there is a lot of useful information and very knowledgable people.

http://www.candlepowerforums.com/vb/forumdisplay.php?f=9

Thanks for the useful information.
My lights that use lithium Cells:

SOlarforce L2m (moded to take 14500)
MiNiAA -
Ultrafire A10 (14500)
SOlarforce L2 (18650)
Akoray K106 (14500)
Ultrafire C3 (14500)

I'll check the Flashlight Electronics - Batteries Included section.

 

[PeaceOfMind]

I'm confused with Lithium Cells(w/ protection circuit), Bought them for safety reasons and now I'm thinking If I should have gotten the one's without protection circuit.:thinking:

Bad idea - the protection circuit is preventing you from draining them to the point that they are unsafe and explode/vent with flame possibly causing injury, death and property damage. Basically you're saying that maybe you'd prefer not having the protection circuit so that you can drain the cells down even further (and thus have them dim gradually for a bit at the end, maybe), but this is exactly what you're being protected from for your own safety.

To use unprotected cells responsibly you need to a) know a lot about them and what their limits are and b) be willing to monitor them frequently and have the proper tools to do so

Please be safe. It's not worth risking your health and safety over a tiny bit of flashlight runtime.

 

[Lighthouse one]

These cells are meant to be recharged often. Why do you find it necessary to run the battery until nearly dead? You have enough flashlights to carry more than one. There is no reason to run them down completely....just top them off every month if they aren't used between.

 

[Ian2381]

Maybe your right guys,

I'm just conscious on the situation I've been before where in changing batteries is a big no.

We got lost in one Mt hiking trip and got to a wrong trail by night time while raining heavily, I have to lend all of my other lights to friends and one for me since its a really steep trail and we did not expect that we will not get to the camp site before night.

I'm really glad I joined this forum and I know I'm prepared to situations like that, I just have hesitations in using protected Cells and I think the best thing for me is to use my MiNi AA together with my Lithium powered lights especially during night climbs.

 

[Moonshadow]

OK, thanks for the additional background.

The lights you've listed - Solarforce, Akoray and so on are good lights, but definitely from the budget end of the market. For a mission-critical application like mountain hiking it would definitely be worth investing in something a bit more rugged with features that will avoid the problem you had with those cheaper lights. It simply isn't worth skimping on equipment that your life might depend on.

An RA Clicky for example, will set you back no more than a good pair of hiking boots. When a rechargeable cell starts to run low, it will flash to warn you and automatically switch to a lower level, extending the runtime without leaving you suddenly in the dark. It is designed to do this before the protection circuit is triggered. Team this up with a couple of long-running backup lights like your E01 and MiNi AA. Problem solved.

 

[mdocod]

While I personally would be comfortable going up a mountain with certain flashlights that use say, 18650 cells, I would recommend to others that all extreme exploration should be backed by lithium primary CR123 or lithium AA powered units.

Carry spare lights and spare cells for all. Standardize on one cell type when going up the mountain.

 

[mfm]

While I personally would be comfortable going up a mountain with certain flashlights that use say, 18650 cells, I would recommend to others that all extreme exploration should be backed by lithium primary CR123 or lithium AA powered units.

Why? You get more power with 18650. If you have cheap lights that doesn't warn before the battery level is low, you can go with unprotected 18650 and try not to drain them. If they are too low when you get home then just recycle them, otherwise keep using them.