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Japanese Vs Chinese Eneloop Cycle Testing Results

Posted: Tue Nov 04, 2014 4:53 am
by Mark
At about the start of 2014, Panasonic shifted production of Eneloops for some markets (including Australia) from Japan to China.

The Chinese Eneloops have the same product code as the Japanese made Eneloops and are rated for the same 2100 cycles. The Chinese cells are rated slightly lower on capacity retention with a claimed 65% remaining after 5 years instead of 70%

When I heard about this change, I was immediately concerned that even though the Chinese made Eneloops were rated for the same number of cycles, they may not actually be as good as those made in Japan. Time for another test!

For this test, I took a pair of 4th generation Japanese made Eneloops and a pair of new 4th generation Chinese made Eneloops. I put one of each into 2 separate chargers and set them running with both charging and discharging at 2 amps. 20 minutes rest after charging and 10 minutes after discharging. The results of the test is shown below:

Image

Please note that at the time of posting this, the Japanese Eneloops (shown in blue) are still running where as the Chinese Eneloops (in green) died quite a while ago.

It seems quite clear to me from this test that under these conditions at least, the Chinese Eneloops perform well below what the Japanese made Eneloops are capable of. These Chinese Eneloops have performed better in this test than the 1st gen Japanese made Eneloop that I previously tested, however, that may be due to this test being done over the cooler Winter months. The testing method also isn't exactly the same, so that could also have an effect on the result. It should also be noted that the 4th gen Japanese Eneloops tested better than the one in my previous test as well.

A while ago, I contacted Panasonic Australia to confirm that the Japanese and Chinese Eneloops are rated using the same testing method and was told that they were. Initially, I was told that the Chinese made Eneloops were just as good or even better than those made in Japan. When I pointed out that the Chinese Eneloops were rated for less capacity retention and asked if there was any situation in which the Japanese cells could work better, the response was less defensive of the Chinese cells and admitted that there could be some differences in performance.

About 2 weeks ago, I contacted Panasonic Australia again to seek a comment on these test results. I was initially asked to send through my results and asked for details about my testing methods. I sent those details through as requested, but initially received no response. After a couple of days, I sent a follow up email to see if my previous email had been lost to which I received an email confirming that my email had indeed been lost to the spam folder. In that email, I was told that my results would be reviewed at the start of the following week (now last week). I have received no further response from Panasonic despite sending them a follow up email.

I do understand that moving production to China, etc is quite normal these days, and I can certainly understand the reasons for doing so. What I really don't like is when companies move production to a country with lower wages and reduce the quality, but don't admit to it and continue to charge the same prices as they were before. In Panasonic's defence in this case, it appears that the reduced costs are actually having an impact on local pricing here in Australia. Previous 3rd generation Eneloops generally went on sale at Dick Smith Electronics for $20 for a pack of 8. Since the Chinese Eneloops have made an appearance here, they've been discounted to $15 for an 8 pack numerous times.

It's speculated that when Panasonic purchased Sanyo, they only acquired the Eneloop brand and the Japanese factory that produces Eneloops was sold off to a third party to ensure that there weren't any anti-trust issues that would otherwise block the purchase due to Panasonic potentially controlling an excessive proportion of the worldwide battery production capacity. There are still Eneloops being produced in Japan for some markets, but other markets are being sold Chinese made Eneloops instead. For customers in those markets, it seems that Eneloops are now only Eneloops in name.

Having said all of the above, I'm somewhat disappointed in Panasonic. I have a number of other Panasonic branded items in my household and have generally been quite happy with them all, but this is leaving a bitter taste in my mouth.

Re: Japanese Vs Chinese Eneloop Cycle Testing Results

Posted: Fri Nov 07, 2014 11:11 pm
by Russell McMahon
Summary: It **may** be possible to identify "new style" Eneloop cells by their voltage with time discharge curves at a given discharge rate and there may be discernible differences between current and advertised performance in this area. And, Panasonic may even care.


A friend referred this battery test result to me and I've joined the group to comment. Looks like it should be an interesting forum.

Your Eneloop test results and comments on recent Eneloop manufacturing history may explain 'interesting' test results that I obtained with Eneloop cells earlier this year.
I was not aware of the change of manufacturing source and do not yet know when it occurred or which cells are affected.

Background only: I have been involved with the production of solar powered portable lights in a number of Chinese factories over some years. We have used over 500,000 AA Nimh cells during that time with all the usual interesting experiences which you might expect when attempting to source consistently good quality cells in the Chinese market. Buying cells from one of the "big 3" Chinese manufacturers at prices not vastly higher than from most alternative sources is the retrospectively obvious answer to most problems encountered.

Eneloops: Earlier this year I carried out some relatively simple test cycles on Eneloop cells. My primary short term interest was for low volume personal use in high energy camera flashes but I also wanted to see how they compared in typical lighting applications. As well as the very low self discharge rates I was interested in the Eneloop's claimed somewhat higher terminal voltage across most of the discharge range at modest (say <= C/5) discharge rates. I sourced cells initially from a local retail chain - small but country wide outlets and with direct links to Chinese sources. I was disappointed to find that the advertised Eneloop terminal voltage profiles were not evident and that the cells were not significantly different in voltage output across the cycle at a given discharge rate than a range of other brands of NimH. The cells did have capacities close to what was claimed and in short period self discharge tests (days to weeks) did have significantly superior characteristics to non LSD cells. I concluded that the cells may be non Sanyo LSD products packaged as Eneloops. (In the past I have seen fake Sony cells with superbly copied packaging but greatly inferior cells,)

I obtained 'Eneloop' cells from other retail sources liable to have been supplied via a potentially more reputable distribution chain and found that they had the same characteristics. At that stage I put the matter in my "must pursue sometime soon (may never happen)" basket where it has remained. Your test results and manufacturing source information have revived my interest and I will attempt to source some older Japanese & Sanyo made Eneloops and see if the advertised terminal voltage characteristics are present in the "genuine" cells.

Related: My experience of Panasonic products in general is that they are o a consistency of quality and conformance to specification matched by few other brands. I tell people, light heartedly but with an element of truth "If you need a product and do not have time to do in depth due diligence, and Panasonic make it, buy Panasonic." It is accordingly very disappointing to see that their standards appear to have slipped so thoroughly in the case of Eneloops. However, all past experience with their products suggest that they genuinely care about quality and meeting specifications and that they are liable to either improve the performance of these products to the old levels or, (hopefully not) adjust advertised claims and specification sheets to match reality in the medium term. Whereas in most cases bad specifications and overblown claims are expected, in this case it may actually be worthwhile bringing your results to the attention of Panasonic management at a suitably high level.

Re: Japanese Vs Chinese Eneloop Cycle Testing Results

Posted: Sun Nov 09, 2014 3:50 am
by Mark
Russell McMahon wrote:Summary: It **may** be possible to identify "new style" Eneloop cells by their voltage with time discharge curves at a given discharge rate and there may be discernible differences between current and advertised performance in this area. And, Panasonic may even care.


The easiest way to tell is to check the wrapper and see if it says "Made in China" If you have a Japanese Eneloop to compare to, the Chinese made Eneloops externally look quite different - both the positive and the negative terminals. Lastly, the discharge curve could be used as an indicator, but the label and style of the terminals would be better indications IMHO.

A friend referred this battery test result to me and I've joined the group to comment. Looks like it should be an interesting forum.

Your Eneloop test results and comments on recent Eneloop manufacturing history may explain 'interesting' test results that I obtained with Eneloop cells earlier this year.
I was not aware of the change of manufacturing source and do not yet know when it occurred or which cells are affected.

Background only: I have been involved with the production of solar powered portable lights in a number of Chinese factories over some years. We have used over 500,000 AA Nimh cells during that time with all the usual interesting experiences which you might expect when attempting to source consistently good quality cells in the Chinese market. Buying cells from one of the "big 3" Chinese manufacturers at prices not vastly higher than from most alternative sources is the retrospectively obvious answer to most problems encountered.

Eneloops: Earlier this year I carried out some relatively simple test cycles on Eneloop cells. My primary short term interest was for low volume personal use in high energy camera flashes but I also wanted to see how they compared in typical lighting applications. As well as the very low self discharge rates I was interested in the Eneloop's claimed somewhat higher terminal voltage across most of the discharge range at modest (say <= C/5) discharge rates. I sourced cells initially from a local retail chain - small but country wide outlets and with direct links to Chinese sources. I was disappointed to find that the advertised Eneloop terminal voltage profiles were not evident and that the cells were not significantly different in voltage output across the cycle at a given discharge rate than a range of other brands of NimH. The cells did have capacities close to what was claimed and in short period self discharge tests (days to weeks) did have significantly superior characteristics to non LSD cells. I concluded that the cells may be non Sanyo LSD products packaged as Eneloops. (In the past I have seen fake Sony cells with superbly copied packaging but greatly inferior cells,)

I obtained 'Eneloop' cells from other retail sources liable to have been supplied via a potentially more reputable distribution chain and found that they had the same characteristics. At that stage I put the matter in my "must pursue sometime soon (may never happen)" basket where it has remained. Your test results and manufacturing source information have revived my interest and I will attempt to source some older Japanese & Sanyo made Eneloops and see if the advertised terminal voltage characteristics are present in the "genuine" cells.


The key difference with Eneloops when it comes to discharge curves and holding their voltage under load is that they tend to have lower internal resistance than other NiMH cells. At low discharge rates, the voltage difference isn't as significant as when discharging at a high rate. You might want to try running your tests again at higher currents and see if you can notice a difference - if not, you may have counterfeits.

If you can get some definite genuine Sanyo Eneloops to test, that would also be a good idea!

Related: My experience of Panasonic products in general is that they are o a consistency of quality and conformance to specification matched by few other brands. I tell people, light heartedly but with an element of truth "If you need a product and do not have time to do in depth due diligence, and Panasonic make it, buy Panasonic." It is accordingly very disappointing to see that their standards appear to have slipped so thoroughly in the case of Eneloops. However, all past experience with their products suggest that they genuinely care about quality and meeting specifications and that they are liable to either improve the performance of these products to the old levels or, (hopefully not) adjust advertised claims and specification sheets to match reality in the medium term. Whereas in most cases bad specifications and overblown claims are expected, in this case it may actually be worthwhile bringing your results to the attention of Panasonic management at a suitably high level.


Agreed!

Re: Japanese Vs Chinese Eneloop Cycle Testing Results

Posted: Thu Nov 27, 2014 7:27 am
by Mark
Testing is now complete, so I've updated the chart in the first post.

The Japanese Eneloops lasted for about double the number of cycles that the Chinese Eneloops managed in this test. Please note that the Japanese Eneloops had a lower end capacity than the Chinese Eneloops. Note also, that in all cases, the cells failed due to high internal resistance - the cells are still able to put out a reasonable capacity at low discharge rates.

Re: Japanese Vs Chinese Eneloop Cycle Testing Results

Posted: Tue Jan 05, 2016 1:51 pm
by 2114L3
did panasonic ever respond about your testing and the poor performance with the chinese AAs?

for a bit of battery porn can you post a picture of "the" cell(s) that has done 5000+ cycles?


it would be great if you combined all your eneloop testing on AA/AAA jap/chn gen1-4 as one big article.
best thing that could come of your testing is for panasonic to pay proper attention and get the chinese eneloops up to spec (or ship japanese cells to australia as "premium" units for a few bucks more).

i have ALOT of eneloops and i bought them cause they were the BEST, but if panasonic are only going to be shipping inferior units then i'll try someone elses cells.
i'm sure Panasonic has good intentions at the end of the day, they dont have a name for being cheap and i'm sure they dont want to start now.

Maybe your content can be the gentle nudge they need, when a million people see it on hackaday....

Re: Japanese Vs Chinese Eneloop Cycle Testing Results

Posted: Fri Jan 08, 2016 12:29 am
by Mark
Going from memory here, I did get some initial response but I think that they stopped responding after a while...

That cell is still cycling as I type this - when I get a bit more free time, I might take a photo of it sitting in the charger and post it up for you.

An article combining the test results for all of the different Eneloop versions sounds like a good idea - that will take quite a bit of work though, so it'll probably be a while before I'll be able to do it!

Re: Japanese Vs Chinese Eneloop Cycle Testing Results

Posted: Fri Jan 08, 2016 3:12 am
by 2114L3
That cell is still cycling as I type this

that is awesome!
lol, that deserves its own webcam with live cycle count.

Re: Japanese Vs Chinese Eneloop Cycle Testing Results

Posted: Fri Jan 08, 2016 3:17 am
by Mark
LOL - I'm sure that it would make riveting viewing! :shock:

Re: Japanese Vs Chinese Eneloop Cycle Testing Results

Posted: Fri Jan 08, 2016 2:43 pm
by 2114L3
haha well - there's a webcam for the longest running light bulb
http://www.centennialbulb.org/

your eneloop on a cam could;
1. be product placement for your charger (if its the same charger, its speaks well of its design and durability)
2. product placement for eneloops
3. draw attention problems with chinese made eneloops
4. leading site for battery porn
5. good laugh

Re: Japanese Vs Chinese Eneloop Cycle Testing Results

Posted: Fri Jan 08, 2016 11:01 pm
by Mark
So, you're thinking about:

www.centenialeneloop.org?

:D