# Test/review of Charger Panasonic BQ-CC65



## HKJ (Feb 15, 2018)

[size=+3]Charger Panasonic BQ-CC65[/size]















This is one of Panasonics top models for NiMH chargers, it can charger 4 AA/AAA with individual control and with a usb charger output port it can also charge a phone or other usb device.



 



I got the charger in a blister pack.






The pack included the charger, mains cable and instruction sheet in a lot of languages.






The charger is powered directly from mains and do not have other power options.






The user interface is a display and 3 buttons.
REFRESH will start a charger-discharge-charge cycle
DISPLAY will select between voltage, time, mAh and Wh (Last two only for refresh) display.
USB OUT will stop any charging and turn the usb output on.
A normal charge is started by putting the batteries in the charger and do not require any button presses.






The display has a nice blue background light, but it turns off fairly fast (It is still possible to read the display).






When putting batteries in the charger it will animate the blocks in this display for a few seconds.






Then it will show the total number of batteries it has charged.






When refreshing batteries it is possible to see mAh






And Wh.






When usb is selected all the charger stuff is turned off.





As usual there are some specifications on the back of the charger.






The usb output is clearly marked with voltage, but not current (It is on the label under the charger).













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



















[size=+2]Measurements charger[/size]



When not powered it will discharge the battery with below 0.03mA
If the charger detect an error the display will show error
When charging an over discharged battery the charger will show a spanner, it disappears around 1V.
The charger use peak currents up to 3.2A
Voltage display is within 0.02V
Charge will restart charging after power loss, or battery insertion.
Power consumption when idle is 0.23 watt
Charger reports "FULL" 15 minutes into top-off charge.
Charger counts total number of cell charged.







The charger stops when the battery starts heating up and then it supplement with one hour top-off charge at around 150mA.
With a single cell the average charge current is about 1500mA, the termination is a bit early for -dv/dt, it could be voltage or a smart algorithm.
Display show 1:33 in charge time. The charging only takes about 78 minutes, this means the charger first reports FULL about 15 minutes into the top-off time.














The other 3 slots looks similar.






The eneloopPro is charged find.
Display show 2:01 in charge time.






The powerex is getting old, but it was charged.
Display show 2:12 in charge time.






The AAA cell is charged fine.
Display shows 1:40 in charge time.






The full cell is detected in about 10 minutes and it also gets a top-off charge.






With four batteries the charge current is reduced.
Display shows: 2:55, 2:55, 2:54 and 2:55 in charge time.






M1: 35,9°C, M2: 40,4°C, M3: 42,6°C, M4: 41,7°C, M5: 49,8°C, M6: 41,9°C, HS1: 54,0°C






M1: 35,1°C, HS1: 41,1°C






When turned on the charger plays with the lights and shows how many cells is has charged, but that does not delay charging, it is started after a bit over 1 second.






With one or two cells the charger will use a 50% duty cycle while charging.






With 3 or 4 cells the duty cycle is only 25%.






Top-off charge, it is the same 3A pulses.






Below 1V the charger uses a "low" charge current, it will first use full charge current above 1V.



[size=+2]Refresh[/size]

Pressing the REFRESH button when the charger has started will switch into refresh mode.






A refresh will charge the battery including the top-off charge, then discharge the battery to about 1V, before charging it again. 
Display shows: 1:33, 1907mAh, 2:25Wh






Display shows: 1:33, 1918mAh, 2:30Wh






Display shows: 1:34, 1924mAh, 2:25Wh






Display shows: 1:33, 1879mAh, 2:27Wh






With 4 batteries the charge rate is slower, but the discharge is at the same speed.
Display shows #1: 2:59, 2013mAh, 2:12Wh
Display shows #2: 2:50, 1906mAh, 2:05Wh
Display shows #3: 2:58, 2006mAh, 2:16Wh
Display shows #4: 2:57, 1953mAh, 2:10Wh
I wonder why I get slightly higher mAh and lower Wh compared to single cell, it might be coincidence or it might be the charger.







M1: 32,5°C, M2: 36,7°C, M3: 36,8°C, M4: 34,2°C, M5: 43,3°C, HS1: 59,3°C






HS1: 36,5°C






Discharging uses pwm to control the current, my scope says the current is 390mA.






A bit later, the voltage on the battery voltage has dropped and the pwm is discharging more of the time to keep the current fairly constant.



[size=+2]USB output[/size]



Usb output will turn off if load is below 100mA for 1 minute.
Output is coded as Apple 1A (Why, it is not used anymore)
When usb output is turned on the charger will not charge batteries.







The charger can deliver 1.15A before overload protection kicks in.






And it also works the same way at 120VAC






No problems running one hour at 5V 1A.
The temperature photos below are taken between 30 minutes and 60 minutes into the one hour test.






M1: 31,2°C, HS1: 32,4°C






M1: 30,5°C, HS1: 34,9°C






M1: 37,5°C, HS1: 44,7°C
The charger do not increase temperature much when delivering usb current.






Noise is 10mV rms and 211mVpp






Noise is 17mV rms and 243mVpp, the noise is low.



[size=+2]Conclusion[/size]

The charger will charge AA/AAA cells nicely and it do not have any trickle charge. Because it is sharing one charge circuit between all four slots the actual charge current is a bit high, but average is fine and it uses lower peak current for AAA cells.
The shared charge circuit also means longer charge time with 3 or 4 batteries in the charger.
Capacity measurement works fine, but as always it takes a long time for this type of test, here it was around 12 hours for 4 cells (One or two cells is about 9 hours).

The usb charger part also works fine, but 1A is a slow usb charger and it uses a old coding.

I will rate it as a good charger.



[size=+3]Notes[/size]

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


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## rjking (Feb 15, 2018)

Once again, Great review. Thanks HKJ


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## marcosg (Feb 16, 2018)

HKJ, Thanks for this great review as usual.
Quick question:
It seems that the output charge for this model is the same as the BQ-CC55 that you also reviewed.
4AA - 750mA 4AAA - 275 mA
Which makes both chargers to be the same as far as straight charging goes (both charges the Eneloop the same way).
The main differences would be the a nice display, USB and refresh (discharge mode) on the BQ-CC65.
Am I correct to see it that way?


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## HKJ (Feb 16, 2018)

marcosg said:


> It seems that the output charge for this model is the same as the BQ-CC55 that you also reviewed.
> 4AA - 750mA 4AAA - 275 mA
> Which makes both chargers to be the same as far as straight charging goes (both charges the Eneloop the same way).
> The main differences would be the a nice display, USB and refresh (discharge mode) on the BQ-CC65.
> Am I correct to see it that way?



Termination do not look the same, CC55 do a obvious -dv/dt termination on most cell, there is not a single of them on CC65 (But the two times the red curve goes above the chart may be -dv/dt).


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## marcosg (Feb 16, 2018)

HKJ said:


> Termination do not look the same, CC55 do a obvious -dv/dt termination on most cell, there is not a single of them on CC65 (But the two times the red curve goes above the chart may be -dv/dt).



Thanks HKJ.
Does it mean the termination on the CC55 is better than CC65 Then?


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## HKJ (Feb 16, 2018)

marcosg said:


> Does it mean the termination on the CC55 is better than CC65 Then?



I am not so sure about it, the CC65 may use Panasonics new way to terminate. 
It may be one of the best way to get a long life of the battery with as much capacity as possible the CC65 uses (Just guessing). Without the 3A pwm it would probably have been even better.


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## marcosg (Feb 16, 2018)

HKJ said:


> I am not so sure about it, the CC65 may use Panasonics new way to terminate.
> It may be one of the best way to get a long life of the battery with as much capacity as possible the CC65 uses (Just guessing). Without the 3A pwm it would probably have been even better.



Thanks HKJ for all of your hard work!


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## iamlucky13 (Feb 16, 2018)

HKJ said:


> I am not so sure about it, the CC65 may use Panasonics new way to terminate.



Do you mean Panasonic is known to have a new method for termination, or is it your guess that they do based on what you've been seeing in testing their newer chargers?

Thanks as always for the solid review.


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## HKJ (Feb 17, 2018)

iamlucky13 said:


> Do you mean Panasonic is known to have a new method for termination, or is it your guess that they do based on what you've been seeing in testing their newer chargers?



I believe it was with the CC55 charger they talked about a new termination method, but I could not see it in my tests. This time around the termination looks different.

It is not the only charger that terminates this way, a project called ultrasmartcharger did also use it: http://www.ultrasmartcharger.com/phpBB3/viewtopic.php?f=3&t=5


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## marcosg (Feb 17, 2018)

HKJ said:


> I believe it was with the CC55 charger they talked about a new termination method, but I could not see it in my tests. This time around the termination looks different.
> 
> It is not the only charger that terminates this way, a project called ultrasmartcharger did also use it: http://www.ultrasmartcharger.com/phpBB3/viewtopic.php?f=3&t=5



Thanks HKJ for the link. I read it and there are some good information, however I have two questions that are not related to this topic and I apologize for that. 
Under that link someone mention about chargers with a internal cooling fan. My question is: Does the cooling fan make the Charger any better? I have a bunch of different chargers such as Maha C9000, opus, four types of a Panasonic’s, Xtars and so forth. None of them have cooling fans (I believe he reffers the cooling fans is mostly for the internal parts of the chargers) Would they affect the life of my Enelloops because they all, the cells and the chargers get a bit warm at the end?
lastly, there are a bunch of chargers nowadays that are for all types of batteries. Isn’t it better to have specific chargers for an specific type of battery instead one charger That can charge all types of batteries?
Sorry for so many questions.
Your review for this CC65 is great and I’ll be getting one as soon I can find a reliable place that ships to US.

Thank you again HKJ


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## HKJ (Feb 17, 2018)

marcosg said:


> Under that link someone mention about chargers with a internal cooling fan. My question is: Does the cooling fan make the Charger any better? I have a bunch of different chargers such as Maha C9000, opus, four types of a Panasonic’s, Xtars and so forth. None of them have cooling fans. Would they affect the life of my Enelloops because they all make the cells and the chargers a bit warm at the end?



Depends, batteries do not like high temperature and in a compact charger it is difficult to avoid it heating the batteries, a fan can improve that.
Other ways to reduce the heat is to use very efficiency electronic or move it away from the batteries (Easier in larger chargers).



marcosg said:


> lastly, there are a bunch of chargers nowadays that are for all types of batteries. Isn’t it better to have specific chargers for an specific type of battery instead one charger That can charge all types of batteries?



No, you can just as easy implement charge algorithms for different batteries in the same charger, one very good example is SkyRC MC3000.
But it will often be cheaper to make the charger for one type only.


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## marcosg (Feb 17, 2018)

👍 Thank you


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## John Bentley (Feb 17, 2018)

*## Possibly the best beginner charger
*
HKJ, this is a great review (as usual). I particularly like that you've thrown a good range of batteries at it: Standard AA, Standard AAA, Pro AA, and an old battery (a powerex). That both: gives the charger a good shake to see if will break; and helps establish that the BQ-CC65, because it charged and terminated fine in all cases, is a good candidate to be regarded as the leading beginner/use-without-thinking-too-much charger. 

On that later point, a beginner/use-without-thinking-too-much charger, it seems to tick many of the necessary boxes:


 Visual termination alarm. 
 Slot independent charging (excepting charging rate varies based on how many are being charged). 
 Form factor (AAA V AA) determined charging rate. 
 Smart and kind charging and termination method.  
It's quite clever that the only time a mAh figure is displayed is after a refresh operation, and the mAh figure references the discharge routine. Beginner users seeing that will understand that as THE Capacity of the battery. They won't get confused by, if the design were otherwise, a mAh figure that is very low after they have charge a battery from a partially charged state (where they wrongly think the mAh reflects the capacity of the battery rather than the capacity so far put in by the charger).

*## Termination method algorithm*




HKJ said:


> I believe it was with the CC55 charger they talked about a new termination method


Yes, there's UltraSmartCharger Forum > Features of the BQ-CC55 charger "peak sensing tech" which possibly indicates that panasonic's "peak sensing tech" more or less is the same termination method that Mark Griffiths (firmware author of UltraSmart charger) uses: a custom version of "inflection" termination (which you linked to). Excepting Griffith's termination doesn't throw in a top-off charge.

So it seems the exact algorithm that panasonic is using to opaque to us. But whatever the particulars your tests make it clear that the charger is stopping the standard charge early, compared to -dV/dt termination, and finishing with a low rate "top off" charge....

*## Termination method*

HKJ Wrote, above ...



> It may be one of the best way to get a long life of the battery with as much capacity as possible the CC65 uses (Just guessing)


That seems consistent with Silverfox's comments when celebrating the similar looking charge profile/termination method in the Maha Engergy Powerex MH-C9000 case.



> MAHA chose to terminate the charge at 1.47 volts and then follow it with a 100 mA top off charge for 2 hours. During that 2 hours the cells voltage does increase to around 1.54 volts indicating a full charge. Pulling the cell at DONE gives you about 90% of maximum capacity. Once again there is a trade off. Treat the cells gently during charging gives you more cycles from the cell, but if you need them quickly you end up with slightly reduced capacity.



A key advantage of the BQ-CC65 is that the top-off charge ends (after 1 hour), whereas the MH-C9000 follows its top-off charge with a never-ending trickle charge. In terms of recommending a charger to a beginner that would seem to make the difference.

It would be good to see a head to head cycle life test with between -dV/dt termination and a standard-charge-finishes-early-with-top-off charge profile.

*## Are low standard charge rates a worry with this charger?*

There's general wisdom floating about that for NiMHs the charging rate should be between 0.5C and 1.0C. For a standard Eneloop AA (Typical capacity 2000mAh) that would entail a charging rate between 1000mA and 2000mA.

For example Silverfox comments (SilverFox, 08-26-2009, 08:42 AM, "Re: Appropriate Charge Rate for NiMH Batteries") ...



> There is enough evidence to support charging in the 0.5 - 1.0C range that the battery manufacturers actually recommend it


Indeed, from Panasonic (on NiMHs, presumably non-Eneloop given Panasonic hadn't acquired Sony yet) (Panasonic - Charge methods for Nickel Metal Hydride Batteries. 2005. “Charge methods for Nickel Metal Hydride Batteries.” In Nickel Metal Hydride Handbook, 12-13)...



> Rapid charge current: 1CmA (rapid charge temperature range: 0°C to 40°). In order to exercise proper control to stop rapid charge, it is recommended that batteries be charged at over 0.5CmA but less than 1CmA


But from your test, an AA in one slot is charged at 1500mA, and in 4 slots simultaneously they are each charged at 750mA. That is, when 4 standard Eneloops are charged simultaneously, this is done below 0.5C (about 0.38C). 

Are we to regard this as fine because:

1. The "between 0.5C and 1.0C" recommendation is made on the assumption that -dV/dt termination is used. And for that termination to succeed we need those relatively higher charging rates so that termination is not missed - but for the BQ-CC65 we are assuming the termination algorithm does not depend on a particular standard charging rate; and
2. Your test show that the charging rate of 0.38C terminate fine with this charger.

?

*## Incidentally ...
*
Does this charge have an audible alarm when "full"?

Why are you not showing your usual vertical yellow termination line in the graphs?


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## HKJ (Feb 18, 2018)

John Bentley said:


> Does this charge have an audible alarm when "full"?




No




John Bentley said:


> Why are you not showing your usual vertical yellow termination line in the graphs?




My chart drawing software usual place these lines automatically where the current drops, but because this charger first finished 15 minutes later I could not do that (And I was a bit too lazy to do it manually).


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## ChibiM (Feb 21, 2018)

Thanks for the review HKJ!


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## linpp (Nov 22, 2018)

Noob here,
What exactly does the wrench on the display mean?
All the manual says is: 'Maintenance charging*'
I have currently 2 eneloops with 'full and the wrench on the display
Thanks


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## emhava (Sep 17, 2020)

*Re: Test/review of Charger Panasonic BQ-CC65 - charger noise*

Thank you for the review. I bought one of those based on it . One question please : Is it normal for the charger to make a tiny ticking sound to start with? With time it starts going into a zzzzzz zzzzzz type of intermittent, regular sounds. Is this normal or a sign of a poor quality / fake ? Many thanks. 

Re: linpp's Q - I interpret the wrench as a partially broken battery - that still works but not in full capacity. My book is similarly sparse on info on the wrench.


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## HKJ (Sep 19, 2020)

*Re: Test/review of Charger Panasonic BQ-CC65 - charger noise*



emhava said:


> Thank you for the review. I bought one of those based on it . One question please : Is it normal for the charger to make a tiny ticking sound to start with? With time it starts going into a zzzzzz zzzzzz type of intermittent, regular sounds. Is this normal or a sign of a poor quality / fake ? Many thanks.



Anything with a switch mode supply can make some usually high pitched low level noises. It is fairly normal and not something to be concerned about.
The ticking sound will usually be when the charger is idle and is each time some power is converted from mains voltage to low voltage. This power will charge a capacitor and when some of that power have been used the next tick will sound. When charging this ticking will speed up, usually well beyond hearing range, but on yours I will guess it is the zzzzz sound, the intermittent nature is because a NiMH charger stops charging at regular intervals to check the voltage.


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## fergambo (Feb 12, 2022)

After reading all HKJ and ChibiM info (thanks a lot!), some years ago I got a BQ-CC17 due to I'm in no hurry to load my Eneloop most of them Special Editions. I had too a BC700 to test/refresh, but due to I got a little tense having to take out the batteries to avoid final trickle charge,
I've just bought the BQ-CC65 to test capacity.
But I'm really confused: after a dozen of Eneloop 'refresh', none reached the minimum theoretical capacity (1900/750 mA) and this only had happened a few times in last 7 years testing Eneloops in my BC700.
BC-CC65 even some cases a 2nd refresh results a capacity decreased almost 100 mAh, so I quite doubt the accuracy, I'm not sure if it's a (bad luck for me) deffective unit. Attached pictures of the result of a 3 units refresh
I consider returning it, so any idea would be really appreciated


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## fergambo (Feb 13, 2022)

According to the BQ-CC65 review, the charging termination would be for -dv/dt or could be voltage or a smart algorithm. 
Comparing the review graphics my charger final voltage after refresh is low (1,44-1,48) always under 1,5 V, not about 1,54 V as seen in review graphics, and as in BC700
May be Panasonic has updated the end charge condition, but no sense if the result is not taking advantage of the capacity of the battery.
Or my unit is not working well, cause I've tried with 'old' and 'new' Eneloops, there are differences


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