Rechargeables and Flashlights

[Capt. Beefheart]

I've got a question that I think could be answered quite easily.

I've read in several places that rechargeable batteries can be damaging to flashlights. However, I often see that eneloops are tested by people. Are eneloop batteries different from standard rechargeable batteries in the aspect that they aren't potentially damaging to flashlights?

 

[HKJ]

I've read in several places that rechargeable batteries can be damaging to flashlights. However, I often see that eneloops are tested by people. Are eneloop batteries different from standard rechargeable batteries in the aspect that they aren't potentially damaging to flashlights?

Alkaline can be damaging for flashlights (They leak), not NiMH batteries, with one exception: Some cheap lights depends on the resistance in alkaline batteries to limit the current, they may run to bright and hot with NiMH batteries.
Eneloop are different form ordinary NiMH, because they have a very low self discharge. They are also good at delivering high current.

 

[Locoboy5150]

Alkaline can be damaging for flashlights (They leak), not NiMH batteries, with one exception: Some cheap lights depends on the resistance in alkaline batteries to limit the current, they may run to bright and hot with NiMH batteries.

I believe that LED Lenser flashlights use the above scenario.

 

[Capt. Beefheart]

Cheers to you two.

The information is much appreciated.

 

[Robin24k]

If the light is regulated, there would be no problem. Only for direct-drive lights would the problem HKJ mentioned be an issue, which tend to be multi-white-LED 3AAA lights.

 

[Lynx_Arc]

If the light is regulated, there would be no problem. Only for direct-drive lights would the problem HKJ mentioned be an issue, which tend to be multi-white-LED 3AAA lights.

I had a 8x5mm LED 3AAA light once that on alkalines it put about 250ma or so to the LEDs or about ~30ma, I got some cheap nimh and found they put about 350-400ma to the LEDs or ~40-50ma to each LED and one LED died, then 2 more then 3 more. 5mm LEDs in parallel that are not perfectly matched one can get a lot more current than the rest due to lower Vf and it will then fry once it does the current has to be distributed to the rest causing them to fail faster and driving most 5mm LEDs over ~30ma can cause failure problems in a short amount of time.
The lights using high power luxeons or crees usually can handle the extra current overdriving them just reduces their longevity from 10k hours to 2k hours etc but the savings in batteries can pay for a cheap light or replacement emitter in that amount of time on such items.
Basically I would research about any 3 cell (1.5v alkaline) based light before adapting to nimh to see if it indeed relies on battery voltage sag to limit current to the LED(s).

 

[vali]

Try to avoid 3xAAA flashlights and you should be in the safe zone.

 

[march.brown]

I have several AAA torches that use three cells ... Solarforce L2i , Romisen RC-U4 , Saiko SA-8 , Zhongsheng , and a cheapy with multi-LEDs (for my Wife) ... All of these work great with either primary cells or more usually with LSD AAA cells ... I eventually went on to 18650 cells on the first three torches on my list to give a longer battery life ... My Wifes (no-name) cheapie has not failed yet on its three Hybrios, but if it does fail I will let her have the Zhongsheng and replace it with another iTP A2.

The Saiko (18650) and the Zhongsheng (3AAA) live more or less permanently in the car glove-box.

I haven't checked currents in any of my torches, so particularly on the cheaper ones perhaps they are "living on borrowed time".
.

 

[McAllan]

I believe that LED Lenser flashlights use the above scenario.

Well, they used to do. Can't speak of their newer models though. Could be they have learned their lesson - you never know. Even Mag seems to have learned theirs except for their very low price/performance ratio outside US.

Wouldn't exactly call LL cheap.
Some of their newer models seems tempting om me with their adjustable focus but I hasn't bought any since I can't find info about it using an appropriate driver or what. If not it's too much money to throw out (I'll use them with NiMH).