Mini-test: Sanyo MQH02 vs Sanyo NC-TGR02 for AA Eneloop charging

[mfm]

I decided to test the temperature profiles of two Sanyo chargers.

I used four 'normal' AA eneloops (HR-3UTG) discharged to around 1.20V resting voltage (even though some had climbed up to 1.22-1.24 after a day).

Sanyo MQH02 Super Quick Charger: Will charge two AA eneloops in around 60 minutes according to the datasheet (charge current is 2 x 2140 mA).

Sanyo NC-TGR02: Will charge two AA eneloops in around 230 minutes according to the datasheet (charge current is 2 x 550 mA). It is part of the eneloop charger line released together with the new 1500-cycle eneloops (HR-3UTGA). It just says 'eneloop' on the front.

Here is the testing in progress:

(the HR-3UTGA cells in the center are not tested, maybe another time)

and here are the results:

These are maximal temperatures (one cell is cooler, and one of them terminates earlier than the other).

The MQH02 terminates after 53 minutes and the cell voltages are (after one minute or such): 1.48 and 1.46 (terminated earlier).

The NC-TGR02 terminates after 254 minutes(!!) and the cell voltages are 1,45 (terminated after 216 minutes) and 1.49. Maybe it took longer because it is a wall-wart type and it was laying down, but I will just write that up as another negative with wall-wart type chargers.

Another diagram with only the MQH02:

I think the MQH02 termination is quite impressive, it terminates just after delta-T exceeds 1 degree C/minute, which is the ideal termination condition according to the Duracell datasheet and others.

It would have been more interesting to try the NC-TGR03 (Two AA eneloops in 100 minutes, also part of the new line) instead of the NC-TGR02, but it is quite expensive and another dreaded wall-wart. I also don't collect nor need more chargers. It seems that neither charger have any trickle charge (I know that the MQH02 doesn't)

MQH02 is clearly the winner in my book.

 

[davidt1]

Thanks for doing the test. Who sells the Sanyo MQH02?

 

[mfm]

Who sells the Sanyo MQH02?

It is available on eBay atleast.

 

[Black Rose]

Sanyo NC-TGR02: Will charge two AA eneloops in around 230 minutes according to the datasheet (charge current is 2 x 550 mA). It is part of the eneloop charger line released together with the new 1500-cycle eneloops (HR-3UTGA). It just says 'eneloop' on the front.

Interesting.

The NC-TGR02 is not a new charger.
It looks like they gave the old NC-MDR02NU a new model number when they brought out the latest Eneloop cells.

With the exception of the different printing* on the front of the charger, the NC-TGR02 looks identical to the NC-MDR02NU charger I bought almost 2 years ago.

The specs for the NC-MDR02NU:
AA: 2 x 550 mA
AAA: 2 x 380 mA

* NC-MDR02NU has Sanyo in the upper left corner with Ni-MH and Quick Charger in the lower left corner

 

[mfm]

The NC-TGR02 is not a new charger.
It looks like they gave the old NC-MDR02NU a new model number when they brought out the latest Eneloop cells.

The casing is whiter and the model number is different. It's new enough for me, we don't know if the internals are identical just because they have the same charge rate.

The point with including it is that it is sold in Japan with the latest eneloops and there was some speculation that these 'new' chargers were finely tuned to the special properties of eneloops.

 

[Egsise]

GREAT THX!
Can you test the MQH02 inner slots too, those are slower slots and I use those mostly.
I'll quote your results to my MQH02 thread.

 

[mfm]

Can you test the MQH02 inner slots too, those are slower slots and I use those mostly.

Why use the slower slots? Eneloop datasheet and batteryuniversity recommends 1C.

In any case, discharged two of the newly (2 days ago) charged Eneloops at around 2A for 5 minutes and then charged them again with the NC-TGR02, now hanging in the wall socket as intended. It terminated after 35-40 minutes (didn't check every minute), so it worked somewhat OK now. Both were at 1.5V.

 

[Egsise]

If you charge 3-4 cells the output is only 1A for every slot.

 

[mfm]

If you charge 3-4 cells the output is only 1A for every slot.

I know, but it sounded like you would just put two cells in the middle.

 

[mfm]

While I don't find it on ebay, this charger is available for HKD 140 (USD 18) in Hong Kong. These are MQH02R or something which is different from my korean version above (the HK one is white while the KR release is more grey).

It certainly smokes the CEF23 and other cheap (too slow) chargers, can take worldwide voltage and has a detachable cord. I would prefer this over any charger in the japanese Eneloop lineup actually...

 

[Egsise]

Why use the slower slots? Eneloop datasheet and batteryuniversity recommends 1C.

From http://www.eneloop.info/home/faq.html

Can I use a "Quick Charger" to charge an eneloop battery?
Though it is possible to charge an eneloop battery in a "Quick Charger", it is not recommended. We recommend charging eneloop batteries in a NiMh charger that is 2 hours or more. Charging eneloop batteries in a "Quick Charger" can reduce the overall life of the battery. It is strongly recommended to use eneloop, Sanyo or Sanyo NiMh battery chargers. We only warrant eneloop if used with an eneloop, Sanyo or Sanyo NiMh battery charger.

 

[mfm]

From http://www.eneloop.info/home/faq.html

The FAQ is written by the MARKETING department, while the eneloop datasheet, written by engineers, specifies 1C.

Stop spreading the fairy tale of the gentle slow charging, see for example my or MrHappys test, or earlier conclustions from others. Or follow the recommendations of EVERY manufacturer out there.

This has been beaten to death already.

On topic, it seems the charger sold in HK is the MQR02N which charges two batteries in two hours, and four batteries in four hours. Oh well...

 

[Egsise]

The FAQ is written by the MARKETING department, while the eneloop datasheet, written by engineers, specifies 1C.

Stop spreading the fairy tale of the gentle slow charging, see for example my or MrHappys test, or earlier conclustions from others. Or follow the recommendations of EVERY manufacturer out there.

This has been beaten to death already.

On topic, it seems the charger sold in HK is the MQR02N which charges two batteries in two hours, and four batteries in four hours. Oh well...

So 0.5C charge is slow..?
And I am not the one spreading false information, isn't it SANYO marketing department that is doing it?

From Maha MH-C9000 charger-analyzers manual: Charging at a rate below 0.3C and above 1C is not recommended.

That's a fairy tale too?

 

[Mr Happy]

It's a bad idea to specify C rates for charging AA batteries.

If you charge high capacity batteries like 2800 mAh at 1C = 2.8 A you will ruin them in short order.

But if you charge high power batteries like Elite 1700 mAh at 2 A = 1.2C they will be quite happy.

So it's best to specify charging current instead. A good charging current for most AA NiMH cells is 1 A, up to 2 A for some high quality cells like Eneloops.

The same goes even for high capacity D cells like 10,000 mAh ones. Pick a maximum charging current of 2 A for those.