Problems with Fenix 5000mAh 21700

[StormW]

I have a Fenix TK16 and it's my favorite light. However I have nerve issues that flare up and sometimes drop the light. This has caused problems with the batteries. The batteries still seem to work but aren't reliable. I think it might have something to do with the charger in the battery. Is there a way to repair this?

I purchased a Fenix E35 and don't have the same problem with damaging the battery.theae aren't hard long drops. Most are maybe 12". I actually like the size of the E35 better for pocket EDC carry but hate the side switch and wish I could get it to work with a tail switch. Is there a way to do this. I have the ability to modify most things as well as weld and solder. When it comes to actual electronics it's probably over my head for the moment. I guess my hope would be to fix the batteries as well as find a way to modify the TK16 so it no longer damages batteries.

I'm new to the forum. I have a good selection of older flashlights in this quality range that I would like to modify in time. I'm a knife maker and in time it could be cool to add custom flashlights to my build list.

 

[turbodog]

From what I saw on their website, it appears to be a standard button top battery... not a flat top.

I'd suspect damage to the button top OR the inside positive terminal of the light. The bottom/negative has a spring to cushion things and is HARD to damage.

 

[aznsx]

I have a Fenix TK16 and it's my favorite light. However I have nerve issues that flare up and sometimes drop the light. This has caused problems with the batteries. The batteries still seem to work but aren't reliable. I think it might have something to do with the charger in the battery. Is there a way to repair this?

I purchased a Fenix E35 and don't have the same problem with damaging the battery.theae aren't hard long drops. Most are maybe 12". I actually like the size of the E35 better for pocket EDC carry but hate the side switch and wish I could get it to work with a tail switch. Is there a way to do this. I have the ability to modify most things as well as weld and solder. When it comes to actual electronics it's probably over my head for the moment. I guess my hope would be to fix the batteries as well as find a way to modify the TK16 so it no longer damages batteries.

I'm new to the forum. I have a good selection of older flashlights in this quality range that I would like to modify in time. I'm a knife maker and in time it could be cool to add custom flashlights to my build list.

Welcome!

It sounds like your current working assumption is that the impact(s) your light has experienced has likely damaged the battery(ies) which were in it during the impact, instead of the impact having perhaps caused a problem with the flashlight itself. That would imply that you've verified that after this has occurred, the flashlight then functions perfectly using a different battery which has not experienced a 'drop' while in the light. Is this the case?

EDIT: Also, what kind / brand of battery(ies) are you using?