Battery won't charge outside of the flashlight

I took this battery out of a nebo slyde king to check it on my opus BT c3400 but no matter which charger that I put it in, it always reads null, however it shows that it is charging in the flashlight.

I tried other batteries in the flashlight that I know are good but the flashlight would not work with any of my other batteries. The original battery works but only in the flashlight.

I’m not sure where to go from here. Any suggestions would be great. Here’s the battery that came with the flashlight.



This is a non-standard cell. Normal cells only have the + terminal on top and the rest of the cell casing is the - terminal.
Do not try to charge it outside the flashlight, you might short the cell.

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Thanks. I took it out of the charger immediately but thanks for the new knowledge.

This means I will have to get a new battery for a backup. I have 2 backup batteries for each one of my flashlights.

Where is a good place to get one for this slyde king?

You can probably only get it from that company directly or from resellers that carry the brand.
That’s why many people on BLF oppose to buying flashlights that use non-standard cells … it’s always a hassle to get those replaced and you’re often paying a premium for lesser quality and capacity cells.

I bought this flashlight a few years ago before I started really getting into flashlights beyond the basic stuff. I also have a nebo redline x but thankfully it uses a standard battery.

I have learned a lot since I joined the forum. Luckily I made good purchases with my other flashlights thanks to reviews on here.

I just ordered a sofirn SC18 for my son. He wanted a small light with a decent throw that used batteries that we have on hand. It came down to it and a wurkkos but the SC18 had a better throw and I like the SST40 LED.

The last 4 lights that I purchased were right angle headlamps for my kids to have a hands free light for emergencies. I found one for $13 that looked like a sofirn and had sofirn battery but it didn’t have sofirn on it anywhere. It turned out to be a decent light. I wondered if it might be made by sofirn for this company but couldn’t find any information.

Yes BECAREFUL with that cell, it looks like proprietary battery where the Inner circle is positive and the outer ring is negative (or which is which).
You dont want anything conductive to bridge among those two… Looks many battery newest Nitecore is having, but with bad safety design.

I ran onto the same problem with my Nitecore P20i UV, thought it was on the verge
of a rotten trick that Nitecore played on their customers. Didn’t even know
this was not a standard 21700 until after I received the light. That non-standard
Nitecore 21700 (which is actually the NL 2140i) costs about 2-3 times as much as a decent 21700. Just looked on their site and they are selling a used one for $12.95. It also tells you on their site that it’s compatible with conventional chargers but don’t believe that either. No way would it fit in my Nitecore D4 or my Gyrfalcon. I had to buy the Vapcell S4 Plus and even on that only fits in one of the bays. Thanks Nitecore, nice job — NOT!

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Yeah I’m going to be real careful before I buy another nebo and I’m glad you told me about the nitecore. I think that is a good way to lose customers.

Once the battery quits working, that will be the end of the flashlight. I don’t want anything like that.

I agree, I have two other NC’s and they have normal 18650 - 21700’s in them.
If I buy another NC in the future, which I doubt will happen, I will make sure is does not have one of these proprietary batts in it… Still thinking it’s a rotten trick that NC
has played with the P20i UV.

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