What are 21700 Batteries? 

You’re welcome 😊

thank you for the recomendation, myself have gotten tricked by chinese products a few times and now i research every thing i buy, nitecore has a good reputation/rewiews and their charger is sweet. good brand.

It is best to use the manufacturer recommended battery in their respective flashlights. However I would make sure they are the 1) Same size, 2) same voltage, 3) same style (i.e. button top, flat top, etc.)

Yes, why not? Fenix is not Olight.

Hello Lalo Villegas, the P20 v2 is compatible with 18650 size batteries so unfortunately does not work with the NL2150.

@@NitecoreStore I’d like to know what lamp is compatible with NL2150R batteries

any answers to this? This would be incredibly nice

@@Fluxyzabc My guess would be no. I think the circuit is protected from doing this. If your battery charges from a powerbank and the powerbank is drained, it could cause the battery to start charging the power bank and that would defeat the purpose. This is just an educated guess though. Most USB ports like that are diode protected to prevent current from going in the wrong direction.

I'd (also) say 'no', simply because Nitecore specifically sells the product F21i. If you could use the USB-C port in the battery to charge another device, then F21i would be obsolete.

Why dont you look at the website? The answer is no.

No, flashlights that were originally designed for 18650 batteries (like the P12GT) will not be able to use 21700 batteries as the inner tube is too narrow. HOWEVER, our new 21700 flashlights include an adapter so you can still use your 18650s.

I checked the xiaomi website, and I cannot find any specs on what batteries they use. All it says it 18650 but that can mean so many things.

Hello, Aqib Iqbal M6, the standard 10W (5V/2A) work for the 5000mAh 21700, and even faster amp chargers. However for Li-ion battery longevity, we always recommend the lowest possible.

Depends on current.

I think so. Now there are a lot of flashlights that use this kind of battery. More lumens, more run time, more battery capacity needed.

No, 18650 is still smaller and holds less capacity the new 21700 is a beast. It’s the cells used in Teslas

26650? Probably, unless someone invests HEAVILY in increasing its energy density. 18650? I doubt it. 21700 is really nice and dense, but 18650 is very compact and portable. Especially for smaller people with small hands.

We do not recommend button top batteries for vape devices.

@@NitecoreStore what is button top battery ?

Hey Mochammad, if you are talking about button top Nitecore 21700 batteries then no, the D2 does not work it is too small. However, the raw flat top 21700 batteries that people tend to use for vapes might. I am not 100% sure because those batteries do not have the protective circuit + button top converter on the battery.

@@NitecoreStore oh isee i think i need to invest more on new 21700 nitecore charger if i buy hc35. but for a while I can use the onboard micro usb on it. thks for quick response 🙏

led goes green

Our 5000mAh batteries are 18Wh and way roughly 75 grams.

@@NitecoreStore Thanks, but I asked about energy density (Wh per kg) (Density gravimetric theoretic)

Hey raven yap, I would check with the manufacturer of your vape mod, but usually you need a flat top battery for vapes and not a button top. Here is one of our guide images. bit.ly/NCS_batterytypes

Are you perchance using the NL2150R instead of the NL2150? I noticed the stats for NL2150R do show 75.2mm or .21in longer than the NL2150. Extra length for the cable charge capability.

@@robar7853 I bought he NL2150R. It is longer than the standard 21700. Even the NL2150 in my flashlight is longer than the standard battery due to the protection circuit.

Thanks for the update. I thought the NL2150 were standard length. I will have to look at the specs a little closer next time.@@MinTongTee

@@robar7853 You could try battery silicon case. It might work since is stretchable.

@@MinTongTee Sorry that I spoke too soon in my early exploration into the 21700 generation of batteries. I naively thought that when the battery was called a 21700 battery (21mm x 700mm) that it met those requirements. I understand that by adding USB charging or circuit protection the dimensions could change, but a basic button top 21700 should fit in a flashlight designed for 21700 batteries. I do appreciate learning that is not necessarily the case before I bought a high priced flashlight that would only take a very limited number of replacement batteries. Thank you again.