2 bay & 4 bay Charger Recommendations for 21700

I’m looking to get a new 2 bay and a 4 bay charger. What do you guys recommend that will work safely/reliably for 18650/21700/26650. Being able to fit 21700 is a must as I see myself getting more 21700 lights and batteries.

What are your best bang-for-buck recommendations? Thanks.

I bought a 4 bay charger for 21700 cells, but I don't know how great it is, and I haven't used it yet.

It accepts very long protected 21700 cell, and it's cheap, which is what I was looking for.

It's the Nitecore UM4:

https://www.banggood.com/NITECORE-UM4-or-UM2-LCD-Screen-Display-Lithium-Battery-Charger-4-Slots-USB-Charging-Smart-Rapid-Battery-Charger-p-1429016.html

...

I probably won't be getting protected 21700 cells, but I was kinda futureproofing with this purchase.

If you are interested, there are XTAR X2 & X4 extended chargers for your reference. These 2 bay & 4 bay chargers are becoming popular among our customers. The chargers can charge 3.6V/3.7V 14500-26650 Li-ion batteries, also 1.2V Ni-MH and Ni-CD batteries, and protected 20700 and 21700 included.

https://www.xtar.cc/product/XTAR-X2-Charger-(Extended-Version)–128.html
https://www.xtar.cc/product/XTAR-X4-Charger-(Extended-Version)–129.html

Vapcell S4+

MiBoxer C4-12 (unfortunately, the entire brand is gone....no more chargers made by them)

Nitecore UM4/UMS4

Sad to hear that the entire Miboxer product brand is gone — may I know what happened to them?

So far I like the Miboxer chargers (C4-12 and C8) — I’ve been using the Miboxer C8 as my “go-to” charger if I don’t need to do capacity testing…

back to the original post… I have tested the Liitokala Lii-600 and it also seems to work OK, and fits 21700 batteries (although protected 21700 won’t fit).

This is my go-to charger. Its much better made than the rest and works great.

I don't know what happended to them. If you go to https://miboxer.com/ you will find a whole new product assortment but no chargers. They seem to be facing some internal "issues" that they want their customers to know about when you open up the page. I agree with you, the C4-12 is a great charger. I wish I had bought the latest version that fits even protected 21700 batteries. Unfortunately, I have read a lot about some failed devices because users reported a cheap circuitry part broke down after some time of usage. It can be fixed though if you can handle a soldering iron and know which part to exchange.

Vapcell S4+ is awesome for about 10 months than it dies and you have to replace it.
Got one sitting in the recycle bin.

I have the Xtar X4, works great. Put the batteries in and let it charge. The only button press is to turn the screen on and off.

If you do find a Miboxer , they do work well. BUT! They do have issues with one bay going bad in the two button 4 bay ones. I know for a fact.

I just tried a 21700 in the c4 zanflare and NO GO :(

I was able to fit a P42A and 30T in my zalflare c4. Tight fit, but it worked. Protected cells will definitely not fit

Bummer! When I clicked that link I got a strange message warning about some I eternal affairs with employees and sales scalping for a few seconds then the main page loaded. I wonder what happened really? Maybe they got bought out by a new company and they decided to drop the charger production in favor of other stuff.

I have two C4-12’s, and a C-8. Bought two C4-12’s when they first came out, because I needed more than 4 bays. Then the C-8 came out, which is what I use most. Never had a problem with any of them charging six 18650’s every day

My Miboxer C8 recently started to develop some issues — it still charges to full well, but the resistance reading is now quite high (as in a 100-200mOhms) for certain slots (which are OK/lower resistance) if I transfer that battery to another slot to charge, and this in turn causes the charge current to automatically be set to very low charge current and thus have a very long charging time, if I don’t manually increase the charge current.

I tried cleaning the slot rail (only outside, since I haven’t tried dismantling the casing to clean inside — if that may help), but it seems the resistance is still usually high. So this has caused me to avoid charging using the higher-resistance slots…

Anyone with this problem and how it might be fixed (maybe need to dismantle the Miboxer C8 casing and clean inside?)

Might be your batteries. Haven’t had that problem with authentic Samsung 30Q flattops. Been charging them everyday since Dec. 2018. I get higher Ω reading with buttontops or buttontop protected cells though. I had one buttontop where the welds came loose, that one read close to 200Ω

Almost all my li-ion batteries are flat-tops (I only keep a few button-tops for flashlights that require button-tops). But it’s not the battery problem — since changing the same battery to another slot will be OK, while placing that same battery to the “problematic” slot will have high-resistance measurement — also I’ve tested several different batteries, even new ones will have high-resistance on the specific slots of the Miboxer C8 (in particular, the high-resistance issue is occuring on my slot #6). I’m not sure how to fix it though (cleaning the rails, didn’t appear to help), but I only cleaned outside — maybe something inside is causing the high resistance reading, and resulting in an automatic low charge current…