Reddit reviews Opus BT - C3100 V2.2 Digital Intelligent 4 Slots LCD Battery Charger Compatible with Li-ion NiCd NiMh Batteries - US Plug (PURPLISH BLUE)

For anyone still using a Wii or Xbox, get some good Rechargeable AAs. Ikea makes some called LADDA, which are really good and pretty cheap. Don't use a cheapo charger though. I have the Opus BT-C3100 which is fantastic, but there are also cheaper ones that are good.

All NiMH AA chargers work with any NiMH AA battery. (Most also charge AAA NiMH batteries.)

The old and dependable 4xAAA or AA, NiMH or NiCad charger is the Maha/Powerex MH-C9000. It can test cells and measure it's capacity, but you have to set the charging current. It's a bit pricey though. ~$53. It's my tried and true and I trust it will last for years.
https://www.amazon.com/Powerex-MH-C9000-WizardOne-Charger-Analyzer-Batteries/dp/B003DIGKOG

My other analyzing charger charges NiMH/NiCad and most types of rechargeable lithium cells 18650 and smaller to 10440. It's not as well built as the Powerex, but charges more types of cells and is less expensive: the Opus BT-C3100
I think the most recent version is v2.2 and is approximately $42
https://www.amazon.com/Opus-BT-Intelligent-Compatible-Batteries/dp/B01852TBOU
I use this to recharge both my NiMH AAA/AA's as well as my 18650 flashlight batteries. Opus has a NiMH only version of the charger, that I've not used: the BT-C2400 that sells for around $30.

For my NiMH C and D cells I use an Ansmann 8 plus charger that doesn't have a fancy LCD display, so cannot be adjusted or show voltage, charge current, nor capacity. But it does have 4 independent charging channels for C and D cells and 6 for AA and AAA cells. Apparently they go for $25 now... I paid a lot more for mine.
https://www.amazon.com/ANSMANN-Universal-Maintenance-Rechargeable-Batteries/dp/B003V89RYS
I use this for the NiMH C/D cells that go into various Nerf flywheel blasters. I also use it for AA/AAA's when I need to charge a whole lot of batteries and the rest of my chargers are already being used.

The chargers at Ikea suck, don't buy them.
The chargers that came with the Eneloop packs that Costco used to sell, are nice individual channel chargers, but they're super, super slow overnight chargers when you put 4 cells in them.

A good source for NiMH/Lithium cell and charger info is the candlepower forums: https://www.candlepowerforums.com/vb/forumdisplay.php?9-Flashlight-Electronics-Batteries-Included

You don't already have the PD35? In that case, I would recommend a different light. The PD35 isn't bad, but the very similar Thrunite TN12 is generally regarded as better around here because:

• It comes in neutral white, which the vast majority prefer over cool white; the PD35 only comes in cool white.
  
• The TN12 does not have timed stepdowns in any mode, while the PD35 automatically steps down twice in the highest mode.
  
• The TN12 can tailstand and the PD35 cannot.
  
• The TN12 has a lower low mode.
  
  Alternately, there's the TC12, essentially a TN12 with a battery included and a MicroUSB charging port so you don't need a separate charger. Coupon code "THRUNITE" will save you a bit of money on either of these.
  
  The batteries I already linked are my recommendation for batteries. Chargers depend a bit on your preferences:
  
  
• The Xtar MC1 and MC2 chargers are about as inexpensive as a safe and reliable charger gets from a US-based dealer.
  
• The Nitecore F1 also acts as a USB powerbank.
  
• The Thrunite C2 is a fully-enclosed design similar to the smaller sealed powerbanks you've probably seen, but with a removable battery. It is not sold separately from the battery, but the included battery is of good quality.
  
• The Nitecore D4 is an inexpensive four-slot charger with a voltage display and the ability to handle NiMH (AA and AAA rechargeable) as well as Li-ion.
  
• The Opus BT-C3100 is a four-slot charger that also handles NiMH (AA and AAA rechargeable), lets you select charging current, displays voltage, tests capacity, tests resistance and reconditions NiMH cells that have lost capacity.

Opus BT-C3100 has been my go-to for months now, though it doesn't get as much love as others.

Ideally married batteries should be from the same manufacturer and the same production batch so they charge the same to full and they drop to the same (safe) discharged voltage when the circuit should detect the low voltage and shut down.
With a fully charged battery married to a half discharged battery, the half discharged battery will fall below it's safe discharged battery because the fuller charged battery will keep the married voltage high enough that the vaper circuit thinks all is well - but the lower battery gets force discharged below it's safe discharged voltage.
In time, the weaker battery can become so badly damaged it is a danger to you. Thus only use matched batteries and a good charger.

Many chargers are cheap junk and a danger to all.all you need to know about lithium chargers
Here is a very good charger.
Opus BT-C3100 Digital V2.2 lithium charger. Sold in many places
I got mine from amazon

The Opus BT-C3100 is another popular 4 cell charger which also has analyzer capabilities.

Opus BT - C3100 V2.2 Digital Intelligent 4 Slots LCD Battery Charger Compatible with Li-ion NiCd NiMh Batteries - US Plug (PURPLISH BLUE) https://www.amazon.com/dp/B01852TBOU/ref=cm_sw_r_cp_api_i_8f.5Ab6PKFA8J

This one is recommended a few places, though I have not bought one yet.

https://www.amazon.com/Opus-BT-Intelligent-Compatible-Batteries/dp/B01852TBOU/ref=pd_ybh_a_65?_encoding=UTF8&psc=1&refRID=HNKJFG4B8QX9Y6XZY8MA

[WTB] Opus BT-C3100 V2.2

If someone has an one that they don't really use anymore I'd be glad to take it off of your hands.

[WTB] Any color temp correcting film to warm up a camping lantern's color temp. 5000k-6000k -> 3000k-4000k.

Here is the charger/tester I bought awhile back.

https://www.amazon.com/Opus-BT-Intelligent-Compatible-Batteries/dp/B01852TBOU

There might be better, I didn't do a ton of research before buying it, it's worked for me for over a year now without issues though.

I highly recommend the opus bc3100

Opus BT - C3100 V2.2 Digital Intelligent 4 Slots LCD Battery Charger Compatible with Li-ion NiCd NiMh Batteries - US Plug (PURPLISH BLUE) https://www.amazon.com/dp/B01852TBOU/ref=cm_sw_r_cp_apa_jSCWzbD6YZ1GK

I use this and love it since it charges all of my AA and AAA NiMH batteries too: Opus BT - C3100 V2.2

The proper way to check them is to charge them up, then drain them using a dummy load, monitor the voltage and current during discharge to then calculate miliamp hour capacity, which tells you how much energy the cell can store. Some battery chargers/testers can do this.

https://www.amazon.com/Opus-BT-Intelligent-Compatible-Batteries/dp/B01852TBOU/

Get a real battery charger.

Opus BT - C3100 V2.2 Digital Intelligent 4 Slots LCD Battery Charger Compatible with Li-ion NiCd NiMh Batteries - US Plug (PURPLISH BLUE) https://www.amazon.com/dp/B01852TBOU/ref=cm_sw_r_cp_apa_l99Myb3D95M1Z

Efest chargers have a good reputation around here, despite their failures with battery labeling. The Nitecore i4 is very basic and has no display that will show your battery voltages, etc, so I wouldn't recommend it. If you're willing to spend a bit more on a fantastic charger I can personally recommend the Opus BT C3100 V2.2.

Consider a smart charger as well, something like this so your rechargeable batteries maintain their health for longer.