LF3XT Shutdown Issue

Budman231 · Jun 9, 2009

I recently used my LF3XT on high for longer than 2 mins. Previously I had never used its max setting for very long. The light shuts down after 2-3 mins on max. Is this normal ? Also, it wont turn back on unless I unscrew the head and put it back on. Any ideas ?

Im using 3v tenergy rcr123s on full charge when this happens. I have not tried it with primaries yet because I only use rcr123's. I was thinking it might be thermal protection?

Bud

BabyDoc · Jun 9, 2009

I suspect that the battery is not taking a full charge.
When you put the battery back into the light, do a 5xC command to check the battery voltage while the light is on MAX before it shuts down. I'll bet it is low since you say the light works in the lower output modes. Your battery protection function is probably turned on and when it senses a voltage demand it can't deliver, it shuts down. BTW, I have never had good luck Tenergy cells. I highly recommend the AW R123's.

Budman231 · Jun 9, 2009

BabyDoc said:
I suspect that the battery is not taking a full charge.
When you put the battery back into the light, do a 5xC command to check the battery voltage while the light is on MAX before it shuts down. I'll bet it is low since you say the light works in the lower output modes. Your battery protection function is probably turned on and when it senses a voltage demand it can't deliver, it shuts down. BTW, I have never had good luck Tenergy cells. I highly recommend the AW R123's.

Thanks BD. helpfull as always. I only used the tenergy cells because I also edc a P2D. As you know they dont work well with 3.7v cells.

LED Cool · Jun 9, 2009

i concurred what babydoc said about the reason for the shutdown.
no experience on the Tenergy cell though.

khoo

baterija · Jun 9, 2009

Budman, if the cells are charged and still good in your Fenix I would suspect yet another possibility - the light is working exactly the way it's designed. On high you'll have the most voltage sag in a cell that has lower voltage out to begin with. It probably looks like a discharged cell.

They do have overdischarge protection built in. I bet you could turn off the low voltage shutdown on your 3XT and use them just fine that way. It would still be interesting to see voltage reports with it on max before it shutsdown.

jimmy1970 · Jun 9, 2009

My fathers LF3XT will only operate at full output on ICR123's. If you use CR123's, it only operates up to around 50% (I've tried 3 different brands of brand new primary batteries and cleaned the contacts etc and get the same result.:thumbsdow Has been fine up till now on primaries (the only type of batteries used until I tested it on ICR123's.

Looks like its going back!:sigh:

James....

mikes1 · Jun 10, 2009

Just to make things clear if you are using anything other than 3.7v RCR,s the voltage protection must be off or the light will shut down to protect the battery. Hope this helps

Mike

Budman231 · Jun 10, 2009

Thanks to all ...
Does anyone know at what voltage it will shutdown. I did BDs suggestion and it looks like 2.8/2.9 volts when I have the problem. Since I have to unscrew the head to get it to work again there is a little delay in getting the report after Shutdown.

Bud

LF3XT Shutdown Issue

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