# Test/review of Charger Panasonic BQ-CC55



## HKJ (Feb 26, 2017)

[size=+3]Charger Panasonic BQ-CC55[/size]















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.



















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



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.



[size=+2]Conclusion[/size]

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.



[size=+3]Notes[/size]

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


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## stephenk (Feb 26, 2017)

Thanks for the review. The effort you put into these reviews is always appreciated.


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## marinemaster (Feb 26, 2017)

Thanks for the review
I like the color scheme they have now. Pretty cool.


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## schuster (Feb 26, 2017)

Thanks again for the review. I had gotten one of these bundled with AA/AAA's at Costco US for a bargain (discussed elsewhere) and was pretty impressed. It's gratifying to see a methodical review that confirms the impression.


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## samgab (Feb 26, 2017)

Seems like a good little starter charger, for parents or people who just want to recharge the batteries and carry on without worrying about things.
3A pulses seem quite high for AA cells, but Panasonic know their stuff when it comes to batteries.
Thanks for yet another excellent review.


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## TKC (Feb 26, 2017)

*Thank you for your review, and I also appreciate your efforts.

I bought that very same charger, a little while ago; I feel better about my purchase, thanks to your review!*


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## Viking (Feb 27, 2017)

Thanks for a great review.
Is there any trickle charge ?


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## HKJ (Feb 27, 2017)

Viking said:


> Thanks for a great review.
> Is there any trickle charge ?



No, there is a one hour top-off charge


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## iamlucky13 (Feb 27, 2017)

Glad to see you were able to do a review of this charger, since it seems to be showing up in many bundles.

What do you mean when say it is critical of older batteries? Does it refuse to charge some of them that other chargers accept?

I'm also relieved to see it charges AAA's at 1.25A pulses, not 3A! I assume you only tested it with a single AAA inserted?

I'm curious how Eneloops hold up long term when charged with 3A pulses versus 1.5 amps continuous. I doubt anyone except Panasonic has detailed data on this though.


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## samgab (Feb 27, 2017)

iamlucky13 said:


> I'm curious how Eneloops hold up long term when charged with 3A pulses versus 1.5 amps continuous. I doubt anyone except Panasonic has detailed data on this though.



I haven't seen any studies on this, comparing constant current NiMH charging vs Pulse charging NiMH cells, but I understand, anecdotally, that there are advantages to pulse charging over constant current.
It goes something like this:
"[FONT=&quot]The time between pulses allows the battery's capacitive reactance to partially discharge, thus lowering the impedance of the battery. The lower impedance allows the next charge pulse to go in much more efficiently, avoiding excessive heat build-up and over-voltage pressure.[/FONT]" and:
"During the charging process, short rest periods of 20 to 30 milliseconds, between pulses allow the chemical actions in the cells to stabilise by equalising the reaction throughout the bulk of the electrode before recommencing the charge. This enables the chemical reaction to keep pace with the rate of inputting the electrical energy. It is also claimed that this method can reduce unwanted chemical reactions at the electrode surface such as gas formation, crystal growth and passivation."
There's no doubt a whole science involved in figuring out the optimum current rate, pulse length, and pause length to best treat cells and for best cycle life/longevity, but I haven't seen any hard data on it.

The other advantage of pulse charging is the cell's voltage can be measured between pulses to get a more accurate V measurement, although it takes more than a fraction of a second for NiMH cells' voltage to settle properly and give the true resting OCV.
But it does remove any in-circuit voltage drop under load, when the measurement is taken during the rests between pulses.


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## HKJ (Feb 27, 2017)

iamlucky13 said:


> What do you mean when say it is critical of older batteries? Does it refuse to charge some of them that other chargers accept?



Exactly.




iamlucky13 said:


> I'm also relieved to see it charges AAA's at 1.25A pulses, not 3A! I assume you only tested it with a single AAA inserted?



Yes. As you can see with AA it uses same current with 1 to 4 cells, only the duty cycle is changed.



iamlucky13 said:


> I'm curious how Eneloops hold up long term when charged with 3A pulses versus 1.5 amps continuous. I doubt anyone except Panasonic has detailed data on this though.



I doubt it has much significance. 3A is not that much above the rated 2A (1C) maximum charge current.


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## marcosg (Feb 27, 2017)

Thanks HKJ for the time you took for this review as well as for all the reviews you have done.
I also have gotten this charger in a bundle. Now that you have done the review for it, how would you compare and rate this charger to the BQ-CC17 that you also reviewed?
Best Regards


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## Cekid (Mar 1, 2017)

@HKJ

since this charger has top off charge as well, my question is: is there ANY Nimh charger which doesn't have this feature? in fact, is there any nimh charger which filled battery 100% when charger itself shows that batteries are full, either by showing done, full, finished, turn led light into green, turn led light off, or whatever various chargers shows when done on lcd screen or else? or every charger has some sort of top off charging, be it 1 or 2 hours?


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## HKJ (Mar 1, 2017)

Cekid said:


> since this charger has top off charge as well, my question is: is there ANY Nimh charger which doesn't have this feature?



Yes.
Chargers that uses voltage termination need this feature to fully charge batteries, but -dv/dt chargers can do without.
With LSD batteries it is best without any trickle charge, but a small one is not a big problem.
This charger is without both: http://lygte-info.dk/review/Review Charger GyrFalcon All-44 UK.html
And there are many other.


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## hiuintahs (Mar 1, 2017)

HKJ, do you think its necessary to do that top-off charge that averages 140mA for an hour after dv/dt? Wouldn't the battery be full say doing the top-off for only 5 or 10 minutes after dv/dt? Thanks again for all the expert advice you provide.


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## HKJ (Mar 1, 2017)

hiuintahs said:


> HKJ, do you think its necessary to do that top-off charge that averages 140mA for an hour after dv/dt? Wouldn't the battery be full say doing the top-off for only 5 or 10 minutes after dv/dt? Thanks again for all the expert advice you provide.



As I already wrote it is not necessary on -dv/dt chargers.


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## Cekid (Mar 2, 2017)

if i understand correctly, this panasonic charger is -dv but it still has 1 hour top off charge? why is that? in practice, it means we never know if charger has top off charge even if it is -dv one before HKJ is doing proper test? 

it seems that we need some sort of a list of true -dv chargers and voltage based ones...i don't know why it is such a big deal to made a charger which is going to correctly show when batteries are 100% full, instead of this top off charge mumbo jumbo...it defies the definition of "smart charger"....


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## HKJ (Mar 2, 2017)

Cekid said:


> if i understand correctly, this panasonic charger is -dv but it still has 1 hour top off charge? why is that?



This charger will switch between -dv/dt and voltage termination, depending on the cell. It would have been nice if it only used top-off after voltage termination.


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## RollerBoySE (Mar 2, 2017)

HKJ said:


> This charger will switch between -dv/dt and voltage termination, depending on the cell.



How is that determined?


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## HKJ (Mar 2, 2017)

RollerBoySE said:


> How is that determined?



Probably voltage, but the voltages are so close it is difficult to be sure.


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## RollerBoySE (Mar 2, 2017)

HKJ said:


> Probably voltage, but the voltages are so close it is difficult to be sure.



So it's more or less random, whichever is fullfilled first?


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## HKJ (Mar 2, 2017)

RollerBoySE said:


> So it's more or less random, whichever is fullfilled first?



Not random, it will depend on the actual chemistry of the cell and the age of the cell.


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## RollerBoySE (Mar 2, 2017)

HKJ said:


> Not random, it will depend on the actual chemistry of the cell and the age of the cell.



Any idea how it's determined?


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## HKJ (Mar 2, 2017)

RollerBoySE said:


> Any idea how it's determined?



Usual it is voltage, together with a -dv/dt and maybe a 0dv/dt algorithm.
The one tripping first stops the charge (0dv/dt will have a longer time constant than -dv/dt).

If you want more details about the different terminations, check my article about NiMH charging: http://lygte-info.dk/info/batteryChargingNiMH UK.html


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## RollerBoySE (Mar 2, 2017)

HKJ said:


> Usual it is voltage, together with a -dv/dt and maybe a 0dv/dt algorithm.
> The one tripping first stops the charge (0dv/dt will have a longer time constant than -dv/dt).
> 
> If you want more details about the different terminations, check my article about NiMH charging: http://lygte-info.dk/info/batteryChargingNiMH UK.html



Thanks!


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## Viking (Mar 6, 2017)

According to panasonic this charger uses a different termination method than an ordinary -dV.
They call it “peak sensing technology”.

It senses the slope of the voltage curve, and terminates a little earlier than a -dV termination would have, much like the inflection method used by the Ultra smart charger, where this charger also has been mentioned for the same reason. I suspect thats the reason for the one hour top off charge.
Below the comparing table of the CC55 and CC17 CHARGER (at page 7 at the link below), there's a little graphic explanation of this termination method. As can be seen, it looks much like the inflection method explained by PowerMeUp. 

http://nacs16.mapyourshow.com/7_0/c...d2bbc4002-91D888B9-F362-F2E9-98FF6F4972DA45FB





> *The inflection metod explained by PowerMeUp:
> *The inflection method is a bit more complicated. For this method, the charger is watching the slope of the voltage and when the slope starts to drop off from the peak, it's taken as a sign that the charge is complete. In the above graph, the inflection point occurs at about 1800mAh. I'm going to do it a little differently and stop the charge when the slope drops to below half the maximum. Standard inflection termination tends to undercharge batteries a little, but my modified method will terminate a little later - it should occur just after the temperature has started to increase and so lead to a pretty full battery without any significant overcharge.


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## HKJ (Mar 6, 2017)

Viking said:


> According to panasonic this charger uses a different termination method than an ordinary -dV.
> They call it “peak sensing technology”.



When looking at the curves it is difficult to see that they uses any special technology to sense termination.


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## Viking (Mar 6, 2017)

HKJ 
About the LEDS, will they go off (indicating a fully charged cell), after the ordinary termination, or after the top-off charge has finished. 

BTW I think this is an interesting charger, I might buy one.


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## HKJ (Mar 6, 2017)

Viking said:


> HKJ
> About the LEDS, will they go off (indicating a fully charged cell), after the ordinary termination, or after the top-off charge has finished.



As usual the top-off charge is hidden, i.e. the leds go off after the main charge.


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## Viking (Mar 6, 2017)

Thanks :thumbsup:


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## carnage (Jul 4, 2017)

When you said the top off charge is hidden, Do you mean light goes off to notify the charge is finish and you have to let the battery sit in the charger longer to finish charging?


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## HKJ (Jul 4, 2017)

carnage said:


> When you said the top off charge is hidden, Do you mean light goes off to notify the charge is finish and you have to let the battery sit in the charger longer to finish charging?



Exactly, chargers usual do top-off that way.


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## carnage (Jul 4, 2017)

HKJ said:


> Exactly, chargers usual do top-off that way.



Thanks for the reply!
Once the light goes off. how long should they stay in the charger to be fully charged? Is there any charger for NIMH battery that once they said finish or light goes off there are completely charged?


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## HKJ (Jul 4, 2017)

carnage said:


> Once the light goes off. how long should they stay in the charger to be fully charged? Is there any charger for NIMH battery that once they said finish or light goes off there are completely charged?



This charger needs one hour, some chargers needs two hours.

Generally charger that use -dv/dt do not need a top-off charge, but chargers with voltage termination need it.
And to confuse the issue some chargers use both methods and either has a top-off on both or on neither.

You will have to check the individual reviews to see how each charger works.


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## carnage (Jul 4, 2017)

I have the BQ CC17 and the AAA fit loosely, could I bend the tab up slightly to fit the battery a little snug?


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## speedlever (Aug 7, 2017)

I have a BC-900/Rev 33 charger that I tried to charge some older Sanyo AA Eneloops in today but they never seemed to stop charging. From what I've gathered reading around the 'net, the La Crosse chargers appear to have an issue with Eneloops in this regard. So I read up some over at Wirecutter and some reviews on Amazon from NLee the engineer and picked up the BQ-CC55A kit with 12 Eneloop batteries from Costco for $30 this afternoon.

The BQ-CC55A charged up the old Sanyo AA and AAA Eneloops without issue. But when I plugged in some of my AA NiMh batteries, I got the flashing red light of death. The AA NiMh batteries I tried were:
1) LaCrosse Tech 2400 mAh
2) Energizer 2500 mAh
3) Duracell 2650 mAh

The AAA batteries from Energizer charged without issue on the CC55A.

I'm puzzled why the 3 AA battery types above failed to charge on the CC55A. Did I overlook something basic here? I assumed the CC55 was compatible with all NiMh batteries. The instructions do say for rechargeable Nickel Metal Hydride batteries (and not specifically Eneloops).

My BC-900 charges the above AA NiMh batteries without issue (other than having to jump start some dead ones with an old Energizer NiMh charger to get the BC-900 to see them). Right now is appears I have to charge my AA Eneloops on one charger and my NiMh batteries on the other. This is not the result I expected from the BC-55A charger.


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## speedlever (Aug 8, 2017)

Follow up to my post above, I've spent the better part of this morning trying to find someone at Panasonic who knows anything about the BQ-CC55 charger. Amazingly, no one seems to know anything about the product and I was transferred multiple times, given multiple 800/877 phone numbers to call, transferred to Sanyo products division who also knew nothing about it, etc. I finally found an engineer in the industrial products division who had a passing knowledge of Eneloops/NiMH batterys and chargers and recognized that this product came from their Columbus, GA division. He gave me a phone number to call and I am now awaiting a return call for more specific info on this particular product.

Bottom line at this point (pending further info from Columbus, GA), this charger is specific to Eneloop batteries and/or Panasonic rechargeable NiMH batteries (I have no idea why other rechargeable NiMH batteries would be excluded, and think that only by omission from the following webpage).
http://www.panasonicbatteryproducts...anced-individual-quick-ni-mh-battery-charger/

The product literature I received with the BQ-CC55A charger indicates it "allows AA and AAA Ni-MH rechargeable batteries to be charged in multiple combinations...".

So it appears I still need 2 chargers; one for Eneloops and one for other NiMH rechargeable batteries. Looks like my Lacrosse BC-900 isn't going anywhere anytime soon.


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## speedlever (Aug 8, 2017)

Well son-of-a-gun. I just read this review of the CC55 and it is NOT recommended due to lack of thermal management!
https://www.filterjoe.com/2017/03/11/best-budget-chargers-bqcc55-fct344-bqcc17/

I've not seen this mentioned anywhere else. Looks like I'm back to the drawing board (and plan to return this to Costco).


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## ChibiM (Aug 8, 2017)

What do you mean by thermal management? It has a temp cut off at 57 degrees as far as I know. The cells you mentioned are probably not very healthy anymore and therefore ignored by the BQ CC55.


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## speedlever (Aug 8, 2017)

ChibiM said:


> What do you mean by thermal management? It has a temp cut off at 57 degrees as far as I know. The cells you mentioned are probably not very healthy anymore and therefore ignored by the BQ CC55.



That could well be. But the CC55 seems overly sensitive to me. The Eneloops I tried to charge in my BC900 were generation 1. They charged just find in the CC55, but never stopped charging on the BC900. The Eneloops that came with the CC55 charger are all generation 4 and I haven't had to charge them yet.

The problem I ran into with the CC55 was that it wouldn't recognize my AA rechargeable NiMH batteries... even batteries I just pulled off the BC900 and were fully charged. I just got the flashing red light of death. That being said, it charged my AAA NiMH batteries without a problem. Makes no sense to me.

Panasonic is sending me a CC17 unit to try and compare to the CC55. I'll see how that shakes out in regards to the rechargeable NiMH batteries that won't charge in the CC55. They did tell me they had similar reports on the CC55, so apparently I am not alone.


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## vBDKv (Jul 16, 2018)

As always, thanks for the great review!
I recently picked up this charger and so far it has worked great, however after I tried with 4 batteries, issues occured. After 4 hours I thought maybe I should check the temperature because they were all on yellow. One battery was too hot to touch, the other 3 were pretty warm as well. I measured the first battery (the left one) with a temp gun and it came out at 55c, the rest were about 50c. I then checked the Eneloop website, and they state that Eneloop (White) batteries can sometimes reach up to 50c when charging, so I aborted the charge as the first battery was close to 56c now. I'm somewhat reluctant to try again with this charger in fear of starting a fire lol. It has charged all my AAA batteries, some of my Fujitsu and Eneloop Pro's without a hitch, but I only charged 2 or 3 at a time. First time I tried with 4 batteries is where the 55c issue cropped up.

Not sure if this is an upgrade from the CC17 that I used previously if it will get batteries that high in temp. :huh:


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## tokaji (Sep 18, 2018)

I got this charger today. It is indeed a bit critical with my old batteries  But my old batteries are nowhere near to their rated 1800 cycles.


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## GoGoris (Mar 24, 2019)

Is it safe to charge 2 Eneloop Lite's with this charger or is this not recommended because of the high charge current (over 1C)?


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## radellaf (Jun 28, 2019)

Just got one of these and don't think I'll use it regularly because I haven't had a charger get this hot since the old Maha C401FS on fast mode (1A). The graphs here show it staying under 40-45C, but it routinely heats things up to 50-55C. That may be within spec but it's much hotter than they need to get. Like the 401, the 55 is probably OK if you have a fan blowing on it. Shame you can't select the 3-4 battery rate with only 1 or 2 batteries in it. Maybe if you start with 3 and then remove one? Probably not.

I'll stick to the SkyRC MC3000 for routine use. Stays nice and cool (under 40, at 800mA). Honestly, I prefer the 550mA Eneloop brand chargers like the MDR02 or CC16 to either the 330mA CC17 or the CC55. 750mA should be fine, but maybe it's a bit much for an un-cooled charger with no space between cells.


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## andy999 (Aug 12, 2019)

radellaf said:


> Just got one of these and don't think I'll use it regularly because I haven't had a charger get this hot since the old Maha C401FS on fast mode (1A). The graphs here show it staying under 40-45C, but it routinely heats things up to 50-55C. That may be within spec but it's much hotter than they need to get. Like the 401, the 55 is probably OK if you have a fan blowing on it. Shame you can't select the 3-4 battery rate with only 1 or 2 batteries in it. Maybe if you start with 3 and then remove one? Probably not.
> 
> I'll stick to the SkyRC MC3000 for routine use. Stays nice and cool (under 40, at 800mA). Honestly, I prefer the 550mA Eneloop brand chargers like the MDR02 or CC16 to either the 330mA CC17 or the CC55. 750mA should be fine, but maybe it's a bit much for an un-cooled charger with no space between cells.



what will be the best charger for enellop nimh batteries 1900mah. quite fast but safe and good for battery life. maybe with revive battery option and very expensive, im not pro electrician, just one to rechrge battey for xbox.


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## PartyPete (Aug 12, 2019)

andy999 said:


> what will be the best charger for enellop nimh batteries 1900mah. quite fast but safe and good for battery life. maybe with revive battery option and very expensive, im not pro electrician, just one to rechrge battey for xbox.


I use Eneloops frequently for my Xbox controllers as well. There's plenty of good chargers out there. I use a Zanflare C4 analyzing charger for most everything.


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## bob_ninja (Aug 30, 2019)

I did get it even though I am not a fan of fast chargers. However, it is super rare that I actually have to charge completely depleted batteries. Using all 4 slots I found heat to be fine. I really appreciate the 3 level indication for each channel.

I haven't actually tried 2 cells and full speed since it is rare that I am in such a rush. I do also have the older slow 300ma version which I also use albeit that one can take a very long time for a set of 4 cells, so it is convenient to be able to charge a set in 1-2 hrs. Having 3 level indication also allows me to decide if a cell is almost full and I don't need to go to 100% or it is really empty and needs to charge.

I don't think that the heat is going to be a problem since it would occur only when:
1) cells are mostly depleted
2) charging only 2 next to each other
3) summer warm ambient temps

This set of conditions is pretty rare. In that case I would place it in colder basement and use outer channels 1 and 4. I could even plug it in garage in winter at freezing temps and heat issues are gone.

In general I am charging all 4 so 750ma rate is perfectly fine.


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## bcwang (Oct 28, 2019)

I had picked up a BQ-CC85 in Japan last year. It looks to be the same overall design and charge rate as this BQ-CC55 reviewed here. It seems to have been introduced more recently but I have no idea what's different about it. Does anyone have any ideas or had compared the two chargers and knows how they differ at all?


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