Panasonic BQ-CC87AKBBA eneloop pro Advanced Individual Battery Charger with Portable Charging Technology, Black

If you want to know how to use this device, here's the simple tips in the next 3 paragraphs, but if you want to know why I think this product is so amazing, read the whole thing:Charging: Make sure you are using a USB power source that can provide over an amp of current. If the lights are flashing as you're charging, it will still function, but charge time will take longer and the end of charge determination won't be accurate so the batteries will likely overcharge some and become degraded faster (over the course of many charges). To avoid this, use a USB power source with a better current rating (this is partially a limitation of the charger and partially a limitation of the chemistry; NiMH gives a better end of charge signal when it is charged fast enough).Other than that, charging is pretty simple and straight forward. Watch out for bad connections; if a battery light doesn't show up, try spinning it a little bit while in the charger and it will likely clean up the contact points on the connectors.Power bank mode: There is a minimum current to keep the power bank on - if you have a very low load connected, the power bank will shut off after a minute or so. There are some circuits you can put together to trick this, but just be aware that it's there. Do not use "heavy duty" batteries in this or any 4 cell power bank; they won't work right because that battery chemistry can't supply enough current.Here's, in the technical sense, why I say this is the most advanced NiMH charger+power bank in existence: They created all this functionality using only one inductor. That's why you can buy it as cheap as it is, because the circuit is pretty ingenious and it avoids expensive parts. I don't know how to explain this to non-electrical engineers but if you did "the normal thing" you would expect to see 4 or 5 inductors - one for each cell and likely one for the USB input. And an extra circuit to start it up in power bank mode that might need like a joule thief style transformer. It wouldn't be viable to sell this at a reasonable price point. Basically, instead of treating each cell independently at the circuit level, there's a bunch of solid state switching to select which cells are in series and which are bypassed, so that at any given moment it acts like "one" battery, but the internal computer can reconfigure this quickly when it wants to so that it can end charging to specific full cells or balance draw in power bank mode.This device charges each cell individually (no problem for charge / size mismatch), and assuming it's in its -dV charge termination mode (lights aren't flashing) it charges cells nearly perfectly to capacity.Likewise this is not just a "slam all the batteries in series for power bank mode" thing (well, it is, topologically, but it can also bypass individual cells under computer control so it can work as if they were all separate!) - it is fully regulated in all aspects and enforces a maximum output current just like every other good USB charger. I think it even tries to balance the draw if you have a mix of AA and AAA batteries in it but I've only tested it with 1 AAA + 3 AA scenario but it handled that well.If you made it all the way through this review, I hope you got at least a quarter of the excitement that I had when I first took one of these apart and was amazed at what I saw inside it.

Charges 1-4 batteries at a time via a Micro USB cord. Can also be used as a backup battery pack to charge other objects. Has held up really good so far bouncing around in my backpack.

This charger is expensive. I do like the flashing indicators that aren't too bright, the sliding door that protects batteries in transit, and the ability to use it as a portable charger. Unfortunately, it's 2021 and there still isn't USB-C on what I'd consider to be some of the most "premium" battery products. The gloss back will easily scratch if it is not set on a clean cloth, but the front seems to withstand wear much better. I was concerned that the sliding door would be flimsy or easily breakable, but that doesn't seem to be the case so far. This is great for charging batteries on the go, and I'm confident that this product will last longer than I would use it for. I'm still waiting on a good USB-C product, Eneloop!

very like this panasonic charger . It can act as power bank. The Mobile Charging Functions USB DC 5V output, which uses stored battery power to charge mobile phones and other devices. --> its worth it.when batteries are installed, the charger measures each cell and the corresponding light indicates the remaining chargeHowever this US version did not come with LED light attachment. (BQ-CC87A sold in amazon Japan is include a LED light attachment )Finally it work with ikea rechargeable batteries (which is a older generation eneloop )

While there are slots for AAA batteries, they are too large, and the batteries don't fit, so won't charge. If you only care about AA batteries, it works well for those.

Works fine, just overpriced and made extremely flimsy. Built-in sensor won't let you charge anything other than Enloop. Does what it says it does. Could literally be made by a child from a science fair. I suggest buying another brand that charges universal batteries (*ahem!* Energizer!) for $20 cheaper.

I'm glad Panasonic make this product. I have a small cabin solar system that incorporates USB-C power ports. This unit allows me to charge batteries without having to fire up the inverter, which I'd have to do to use an AC powered battery charger.

This is such an ingenious product. Charges batteries perfectly and I love how you can use it as A power bank. Will be getting a second one for mh earthquake preparedness kit soon. The only room for improvement is the super lite plastic slide cover could be a little more robust it feels Like it could snap off easily, Altho it hasn't. And I wish it had USB c but I think next generation will have it i Hope