Test/review of Charger Panasonic BQ-CC55

Charger Panasonic BQ-CC55

Panasonic has a line of NiMH chargers, some are fast and smart, others dumb. This one here is fairly fast and smart charger.

I got the charger in a transparent plastic box.

The pack included the charger and a instruction sheet.

The charger has a foldable US plug.

The status indicators for each slot is placed in a single line about the slots.

They can show multiple colors:

Red: Battery is nearly empty

Yellow: Battery is partly charged.

Green: Battery is nearly fully charged.

Off: No battery or battery is fully charged.

Flashing yellow: Battery is nearly worn out.

Flashing red: Error

The charger has the typically two level slots used for AA and AAA batteries.

Measurements charger

  • When not powered it will discharge the battery with below 0.03mA

  • If the charger detect an error the red led for that channel will flash fast.

  • Charge will restart charging after power loss, or battery insertion.

  • Power consumption when idle is 0.3 watt

The charger uses a -dv/dt termination and has a 1 hour top-off charge at around 140mA.

The 3 other slot looks the same.

This cell also has a -dv/dt termination.

Here it looks more like a voltage termination, but as can be seen on the temperature the cell is full and get stuffed a bit extra with the top-off charge.

For a -dv/dt charger it is fairly fast at detecting a full cell.

The AAA is charged fine also and the top-off charge is reduced to about 50mA

With four batteries the charger current goes down, but not the top-off current.

M1: 41,9°C, M2: 44,8°C, M3: 44,2°C, M4: 40,3°C, M5: 56,9°C, M6: 48,2°C, HS1: 63,7°C

When turned on the charger plays with the lights, before starting to charge, this takes nearly 5 seconds.

With 3-4 cells the duty cycle is changed, removing the extra cells will not change the duty cycle again.
It looks like the charger has one 3A charging circuit and will switch it between 2 or 4 channels, depending on number of batteries.

The top-off charge is 0.44s pulses each 10 seconds at 3A, this make the current 130mA

Testing with 2830 volt and 4242 volt between mains and low volt side, did not show any safety problems.


This is one of the better Panasonic chargers, it is a bit critical with old batteries, probably due to the fairly high charge current.

The conclusion must be that it is a fairly good charger.


Here is an explanation on how I did the above charge curves: How do I test a charger

Thanks for the review! Seems like a pretty decent charger!

Random unrelated question: where did you get the yellow eneloops? :stuck_out_tongue:

Thank you for testing this charger HKJ. I got this charger with my last Costco eneloop purchase and glad to see that it is a decent charger.

I also have a BQ-CC17 charger which came with the previous Costco eneloop purchase. I see that you tested it back in March, 2015 and you considered it to be a good but slow charger.

Which of these 2 chargers would you recommend to give to my son to charge AAA eneloop batteries?

They do both terminate fine with new batteries, with older batteries the CC17 has and advantage due to the lower current.

I purchased this Eneloop pack at Costco which includes this charger on sale for $23.99. Checking out the charger now.

That sir is an awesome deal! I paid 24 euro for the same charger including only 4 AA batteries.

Yes it’s an awesome deal. That said, I’ve noticed the the yellow indicator on my charger is made up of the red and green LED’s which looks like a pale green instead of the yellow HKJ got on his. Maybe mine is missing a filter of some sort? Not only that, it make a bearly audible beep every second while charging. I’m going to return mine and get a replacement.

I forgot to mention I discharged the Eneloops on my Maha C9000. When I inserted them in the new charger, the LED’s were red. After a while the LED’s turned greenish instead of yellow. That’s when I noticed the both green and red LED’s were illuminated. When I first inserted the batteries, only the green LED’s were illuminated while the charger was doing it’s start-up test

That combo pack is $23.99 at Costco in CT also :slight_smile:
So maybe all of the stores?

You guys are just so lucky. Even if i would buy the charger+10*AA directly at the Dutch import distributor i pay much more from what i have seen.

Thank you for the review!! I have this charger as well, and it is my first charger ever. I bought a DF Titan Plus, and it came with Enelope Pro's, and I needed a charger.

I upgraded from a CC-17 to this, and some of my batteries are reaching up to 55c during charge. They are 4th gen Eneloops, less than a year old. They get so hot that I can barely hold them in my hand O.o

I noticed that happening to mine, too, despite the temps in HKJ and FilterJoe’s reviews. FJ saw 50+ only with 2 AA in neighboring slots. I get it with a single AA or all 4.

If I use this I either am adding a bit of charge in a hurry and pull the cell before it’s done, or I point a fan at it. Too much energy, not enough ventilation. Surprised to see such a bad design from the Eneloop people themselves. The alternative CC17 is much slower than it needs to be. Some older Eneloop chargers ran 550mA, which doesn’t make cells get hot and is enough faster than 330mA to make a real difference. 800mA or so should be fine, but maybe not with the cells packed together so tightly and no fan.