SolarForce L2M AA

Ok folks. I have an L2M with a .8-4.2v p60. It has worked on 1 and 2 aa cell configurations.
the other night I got some new duracell 1.2v 2400mah AA rechargables.
Upon testing the light I found that 3 cells ran the light as bright as an 18650 cell in my other high voltage lights. 2 cells were notably weaker. Very unimpressive. And one cell wont even light the emitter. What happened?
The new cells work great in my Z2.

Not sure I fully understand your question.

You have a p60 with a voltage range of 0.8 - 4.2?

You are saying the new AA (NiMh) batteries work well with three of them (3.6v), not very well with two (2.4v) and not at all with one (1.2v).

You implied the drop in has worked well previously on 1.2v and 2.4v, can you confirm this is what you meant?

If you did are you able to try some different NiMh’s in it to confirm.

Or are you trying to say you think something is wrong with your new AA batteries???

Do you have a DMM? Have you checked their voltages, were they charged? Are they LSD cells, if not, how long was it since charging them?

Have you tried them in any other lights?

How are you fitting 3 AA’s in an L2M? I run the same type of setup using 2-AA’s in a Surefire 9P with a low voltage .8-4.2v drop in. I do not have a configuration where I can run 3-AA’s all at once. If the drop in is in regulation, it should not give any brighter output. Maybe you blew up the drop in or damaged it due to too much voltage? (3-AA’s [estimated at 1.45v each] = 4.35v)

When I use my low voltage drop in with an 18650 at full charge in a L2P, my light output is not any brighter. It is the same as when I use my 2-AA Duraloops.

Exactly what low voltage drop in are you using? A Solarforce P60 running an XP-G?

.8-4.2v

I have the Solarforce extensions that allow you two 18650 ect.

OK. Is the drop in from Solarforce? I assume that you made the same configuration as my Surefire 9P?

Yup. All factory stuff.

Hmmm. I am not sure why the brightness would be different then. I have that same drop in that you have and use it with 2-AA’s.

Weird huh?
3 cell bright as expected
2 cell much weaker
1 cell no joy

When you use the different configurations, is there solid contact being made with the batteries and the springs? Shake the light a little and see if the battery or batteries are loose. I sometimes use a neodymium magnet to take up a little room so I have constant solid contact. I have only used the drop in with 18650 and 2-AA’s. I have not tried a single AA with that drop in. But I do not see the different brightness levels that you describe. Sometimes, drop ins have step down features with various voltage levels. I have an older drop in. Not sure if anything has changed with the Solarforce drop ins.

There is no space. What is the voltage of the 18650? I never considered using 18650 with this dropin.

A fully charged 18650 is 4.2v’s. So that drop in should run in regulation for the entire time that the battery is installed. Newer 18650’s usually have a safety circuit that cuts out about 2.5v’s or so. So it would run from 4.2v down to about 2.5v’s. When using 2-AA’s, you would start out at about 2.9v’s and run down to about 1.6v’s. The AA’s that I have usually don’t run much lower than about .8 to 1v each. If you used a single AA, you would start out at about 1.45v and go down to about .8v.

So what are you saying?: it wont work with 1 AA?

No. It should work with one AA battery. The voltage is within the specs of the drop in. 1.45v from the battery should light up the LED.

My batteries are 1.2v

This happens all the time with the 1AA/14500 lights. The boost side of the circuit has died.

How did it die and now what? Just stick it in 18650 light?

They normally die from high-voltage use: eg from using 14500’s in the little lights. In your case it’s probably from running on an 18650. I do not know how the failure works. If you’ve done anything weird, such as firing up the driver without the LED connected (aka no load), then that could also have contributed.

I guess putting it in an 18650 light is the best thing for it. I don’t have any better suggestions. I certainly don’t recall any examples of people fixing the boost circuit on one of these low-voltage buck/boost drivers.

All I did was load 3 1.2v 2400mah duracell rechargables in it. This sux. I bought that dropin just because of its range ie… 1AA –3AA.

Oh, well that’s certainly what you did wrong. 3x fresh NiMH is over the voltage limit. Hot off the charger you’re looking at 1.5-1.6v. Rested you are looking at 1.4-1.5v.