What we learned from Lunarmodule

Due to the recent Lunarmodule injury ..... what do we learn?

Due to several noted Battery Explosions, it seems like the CPF community needs to adopt some guidelines to keep people safe .... Both flashoholics and the general public alike. I know the photo industry is totally unaware of the dangers of Lithium batteries. My Hasselblad H1 uses 3-CR123 batteries and no one has ever warned me about battery discipline.

Let me start off by sharing some battery discipline that I follow. All of which came from what I have learned about batteries through years of electric r/c racing and here on CPF.

Certain batteries in a sealed flashlight = Pipebomb


1) Buy fresh batteries from only known vendors.

2) Stay away from those import cheapies (settle down....there are good imports and junk imports is my point)

3) I group my CR123 for my needs. Pairs are shrink wrapped and dated for flashlight use and triples are shrink wrapped together for use in my Hasselblad H1

3) Any unknown CR123 batteries go into a box that is only used for single cell flashlight use.

4) If I take a pair of batteries out of a flashlight that are still good.... I tape them together as a used pair.

5) If I get batteries in a used flashlight bought on BST or eBay they go straight into the box labeled for single cell use.

6) I would never include batteries in a used flashlight I sold.

Things I will ad to my procedure since the recent Lunarmodule incident.

- Store Lithium batteries in a foam padded metal container.


If you have any other suggestions this may be a good time to share your knowlege so we all can play/work safe !!!

frisco

i'm confused about all of the reactions to the explosion. why is it bad to send used batteries with the light being sold? is it out of fear that the batteries have not been used in the same light and equally discharged? whenever i get a used light with batteries, i always figure that they were used in that light. is that what can't be assumed?

I think the question regarding using cells that are "used" falls into two catagories
- You don't know the charge condition or use history
- The cells might have been damaged in transit inside the light.

That being said, the FAA considers cells inside a flashlight body to be safer for transport than cells outside of a flashlight body, at least that is how I interpret their rules.

edit
I already respected these cells, and I am not going to go to lights which only use single cells. I really don't think it is safer to use a single cell Li battery to drive a Lux V than a 2 or 3 cell light, and it might be less safe.

The current draw of that flashlight is within the limits of many commercial flashlights, although it is outside of the commercially published discharge curves for CR 123s (1 amp vs about 1.3 amps)

If one takes the time to actually read the package, virtually all battery packs tell you to not mix cells of different charge levels or brands. My guess is that we are all used to ignoring those warnings as "brand reinforcement".

I'm going to keep doing what I've always done.

1.) All loose lithiums(123's and AA's) are brand-spanking-new. "Loose" being defined as any battery that's not in a light or the garbage.

2.) All lithiums stay in their light and with their respective grouping until they're dead.

3.) All discharged lithiums go in the garbage. No exceptions.

If I had a single cell lithium light(It'd be LED, no doubt) I'd consider switching my used lithiums into the single cell light to get most of my money out of the battery. I don't have one and don't plan on getting one, so :shrug: .


Cheers. :buddies:

s.duff said:

i'm confused about all of the reactions to the explosion. why is it bad to send used batteries with the light being sold? is it out of fear that the batteries have not been used in the same light and equally discharged? whenever i get a used light with batteries, i always figure that they were used in that light. is that what can't be assumed?

Click to expand...

I'm not saying at all that this is what happened to Lunarmodule, cause he has stated that the light came from a know high level CPFer. But in general you really don't know if a person reaches into the junk drawer (we all have them) and pulls out two batteries that just look the same but there levels are completely different.

Actually you can get a dead cell from a new batch.... Which brings up the question ... how do you check them? With a volt meter??? Anyone?

frisco

frisco said:

I'm not saying at all that this is what happened to Lunarmodule, cause he has stated that the light came from a know high level CPFer. But in general you really don't know if a person reaches into the junk drawer (we all have them) and pulls out two batteries that just look the same but there levels are completely different.

Actually you can get a dead cell from a new batch.... Which brings up the question ... how do you check them? With a volt meter??? Anyone?

frisco

Click to expand...

High Level CPFer????

Maybe it's time to finally get that ZST battery tester group buy going..


Unless there was one and I missed it??

Dawg said:

High Level CPFer????

Click to expand...

Lunarmodule: I also dont fault the fellow who loaded the batteries, as I said he is an experienced modder who wouldnt knowingly load it with mismatched cells.


frisco

frisco said:

Actually you can get a dead cell from a new batch....

Click to expand...

This is true and has been proven. I agree with what is stated above....we need a way to be able to test cells to ensure that they are at full capacity (or at least same capacity) before we put them into multi-celled applications.

I don't think testing voltage is good enough....we need to know the total % remaining capacity.... Can anyone suggest a tester and a methodology to do this?

These stories keep propping up every now and then...and it is getting scary. It really hit home for me when it happened to Lunarmodule, who I consider a friend. If it can happen to him....it can happen to me.....

WP

I was thinking about this as I woke up - does this mean that perhaps a R Li Ion cell with low voltage discharge protection is now safer than a CR 123 primary ?

Comparing voltage is not a foolproof way to match cells. Even batteries from the same batch will have different internal resistance due to production tolerance or various reasons. With different internal resistances, they will perform differently even when under the same discharge conditions. I match my cells by comparing voltage and internal resistance. They'll have to be within a certain range before I 'll use them in pairs/series. Cells match this way will behave with more consistency and more predictable.

Even with the ZTS tester, the increments are coarse: 20 percent levels, and states of discharge on the border can give different readings when tested twice in a row.

So you have two batteries that test out at, say, 60 percent capacity. But one could be 50 percent and the other could be 70 percent.

The ZTS may be an important help, but I don't think it will be fail safe.

Kevin at BatteryStation has offered to pass around a ZTS tester so we can check our batteries.

The ZTS checking procedure we have developed is to continue to test until you get the same reading 3 times in a row. Some cells will give different readings the first test or two, but then settle down to the same reading for the next 50 tests.

To sign up for the pass around go to the pass around section of the form and post in the ZTS Pass Around thread.

Tom

Just out of curiosity, are there many/any reports of explosions from the military who use SF's on CR123's much more than the average flashaholic?

I'd be careful about matching sets and assuming they will remain matched after a bit of use.

I have matched cells for use in my SF M6 (ZTS matched at 100%) - used the light for a few minutes, let it sit for a few weeks, then re-tested the cells and found 20-40% cells mixed with 80-100% cells

I continually match cells used in my multi-cell high AMP lights - rather than thinking it's a PIA to do this - I am thinking this is the only way to get the absolute best output/performance from these high AMP lights (and added safety is the bonus)

frisco said:

Due to the recent Lunarmodule injury ..... what do we learn?

...

Click to expand...

Replacing a plastic lens with a glass lens can pose a danger if the flashlight explodes. I hadn't thought about that until I read Lunarmodule's posting.

Hi there,

I make all my lights with one Li-ion cell. I never liked the idea of using two in
series. Certainly i would never charge two in series...Never.

BTW, Mr. Wave Particle:
Your signature line:

QUOTE
In the beginning there was nothing. God said, "Let there be light!" And there was light.
There was still nothing, but you could see it a whole lot better.
END QUOTE

Is not correct...here's the actual wording used in the actual Bible:

Genesis Chapter 1
1. In the beginning God created the heaven and the earth.
2 And the earth was without form, and void; and darkness [was] upon the
face of the deep. And the Spirit of God moved upon the face of the waters.
3. And God said, Let there be light: and there was light.
4 And God saw the light, that [it was] good: and God divided the light from
the darkness.

Sorry to have to tell you this but maybe you could correct it.


Take care,
Al

Mr. Al - I know you are WAY ahead of me in electronics and flashlights, but are you really sure that you would only use 1 S Li Ion cell for a light - even if fully protected ? That is a pretty limiting arrangement IMHO.

From my simplistic viewpoint, it is much more hazardous to have a light which drives an LED at constant current, and uses a driver which almost runs the cell in "near dead short" mode to maintain power while the voltage drains out.

Also JMHO, but I am guessing that Wave Particle is just having fun with his sign line and not attempting an actual biblical quote. I kind of like it myself.

HarryN said:

I was thinking about this as I woke up - does this mean that perhaps a R Li Ion cell with low voltage discharge protection is now safer than a CR 123 primary ?

Click to expand...

That is exactly what I was thinking. Cells like the premium PILA's might be worth their weight in gold, given how good/dependable their protection circuitry is

Will

I may be waaay off base, but it seems like the answer to the primary lithium cell problem (if that is really the problem) would be to redesign the battery so that it acts more like a diode - build in a protection circuit to prevent reverse charging. This wouldn't be doable for rechargeables, but is it possible for a primary? Is this just a dumb idea?


Sam