RCR123 behaviour in Surefire G2

[hyperloop]

Hi all,

I have a Surefire G2 (black) running on 2 unprotected RCR123s using a Lumens Factory HO-9.

I ran it till the light went out last night but when i popped the cells in my charger this morning, i found that ONE of the cells seemed to be fully charged as the indicator light on my charger remained green while the other cell charged.

Is it possible that the light used the charge in one of the cells only? Have no clue why this is happening to the cells and would appreciate any input from the more technically inclined here, all i know how to do is charge, measure voltage, insert cell and use the light

 

[csshih]

it is possible the protection circuit is still tripped on the other cell? what is the voltage at?

 

[GeetarHero]

it is possible the protection circuit is still tripped on the other cell? what is the voltage at?

+1 but I think he said he was running unprotected cells. I'm still a noob but I think some of the more respected mebers would agree with me in saying that you should use EXTREME caution when completely depleting Li-Ion cells, especially unprotected ones. Do a little research on Li-Ion cells and please be careful, for your sake and for the sake of your Suefire.

 

[andrewnewman]

Wow. Please be careful. If I got you right, you ran a pair of unprotected Li-Ion batteries in a flashlight with poor heat sinking abilities (Nitrolon) using an incandescent drop in potentially capable of > 300 lumens until the lamp no longer illuminated.

As numerous other threads will inform, Li-Ion's don't like to be over-discharged. They also aren't crazy about heat build up. Problems arise typically on the first recharge after the abuse.

I would count your blessings, toss the batteries and start with a pair of fresh Li-Ions. Please consider protected batteries given the setup you described.

I would guess that you fried both batteries. One is internally shorted and showing no voltage and the other is showing an artificially high voltage with no load that will sag to close to zero under load. This is *just a guess*. I don't think it is safe to recharge these under any circumstances.

 

[Kestrel]

Wow. Please be careful. [...] I don't think it is safe to recharge these under any circumstances.

I can't be certain, but the above post has some very good advice.

 

[Black Rose]

Do you recall what position the "fully charged battery" was in when you took them out? (i.e. at the head of the tail).

If it was at the head, I am betting that the cell reverse charged.
If so, you are very fortunate that it did not

 

[hyperloop]

Thanks for the replies guys.

1. the cells were inserted correctly in the G2 and also in the charger.

2. the light was hot but not overly so

3. it didn't blow up (thankfully) lol

4. both cells have recharged and are working fine, tested them in my cheapo DX dmm and they both read 4.19 - 4.2v, popped each cell individually into my SR3 and it fired up fine.

5. personally, i am very careful with my unprotected RCR123s, topping them up every 2 days or so irrespective of usage and this is the first time the light was left on for that long.

the funny thing was that i think only one cell was drained, the other showed green when inserted into the charger.

 

[joeparker54]

that or it was so dead it didn't even register... what type of charger was it?

 

[mdocod]

A series circuit will always flow the same current through all components. It's impossible to insert 2 cells into a flashlight that has the cells wired series, and not drain both cells down pretty evenly.

It is common for the cell exposed to the heat of the lamp (forward most cell) to wind up depleting itself faster, since it gets heated up and runs at a more excited state of operation (more voltage). But the difference is usually only a few percent.

The most likely thing IMO is that, the charger behaved strangely when faced with the heavily depleted cell. Many chargers will not initiate a charge on a cell if the voltage is too low.

Eric