Japanese Vs Chinese Eneloop Cycle Testing Results

[Power Me Up]

I cannot see any reason why they would even want to reply,perhaps if the test data was some university or similar they may show some interest.

Well... They did show interest by asking for details about my testing method and for my results. Checking the last email that I received, it says that he would look at it early the following week - it doesn't actually say that he would respond though!

 

[StandardBattery]

So does the slow/fast refer to the charge rate at 50 Cycle intervals?

 

[Power Me Up]

It might be possible they are discussing the results, otherwise they might not be interested in a consumer's test.

As I mentioned in my first post, they did show interest in my results and asked me to send them through...

It depends on whether Panasonic wants to investigate this and/or cares enough that the Chinese Eneloops are lower quality and want the best their batteries are capable of providing. The Eneloop videos on the site seem like Panasonic wants a cleaner environment so it would make sense that they want Japanese quality, but it doesn't change the fact that they are planning to switch to Chinese.

A good response from Panasonic could have gone along the lines that they're concerned by my test results and are actively investigating what might have gone wrong - that would certainly inspire a bit more confidence than simply going silent!

One thing i realized with the test here is that you'd probably exceed the 500 cycles with giving much longer rest periods (say weekly or monthly cycling) but that would take too long to test, but i wonder if Panasonic did different tests instead of continually discharging/recharging the batteries whether the batteries need a recovery time in between cycles. Also the quality might have been similar in the beginning but degraded over time. I don't know how long the Chinese have been producing Eneloops for.

There's some discussion of testing methods in the following thread:
http://www.candlepowerforums.com/vb/showthread.php?391756-Eneloop-XX-Vs-Turnigy-2400-Cycle-Testing

Basically, the IEC standard which they're claiming to use is based on (mostly) incomplete charge/discharge cycles and with no rest at all for most cycles. Charge/Discharge rates are also much lower than what I was using in my test. The IEC standard should take about twice as long to run as the test method that I have been using.

I would expect that it's more likely that the quality started lower and has been improved over time as the production process is fine tuned. Since both Chinese cells that I tested were from the same pack, it's possible that they came from a bad batch, or being from an early production run, it's possible that newer cells are capable of more cycles. I'm planning to run another test with at least one more Chinese cell that has been manufactured more recently.

A good question that comes to mind is the fact that the IEC standard that is referenced on the back of the Eneloop packs would take around 18 months to get through 2100 cycles. How on earth have they managed to test the Chinese cells to that many cycles using that method when production in China has only been going for 12 or so months????

Either way it doesn't change the fact the Chinese batteries fell below the Japanese ones which is clear cut that the Japanese Eneloops hold out better. If Panasonic is a trustworthy company which i believe them to be, they'd ditch the Chinese batteries or at the very least do an investigation on how the Chinese are manufacturing Eneloops and make some changes so the Chinese counterparts are of same quality.

It would be really interesting to know what is going on within Panasonic with regard to the Chinese production of Eneloops!

 

[Power Me Up]

It's a big company, and the email probably got stuck in some low-level customer service rep's inbox. Basically, customer service reps aren't interested.

If the email went to someone in quality control, they probably would care. Maybe they did forward it to QC, but a low-level manager got it and decided his department staff had enough work to do and this test wasn't in their mandate.

The person that I was corresponding with is a "Business Manager"

 

[Power Me Up]

So does the slow/fast refer to the charge rate at 50 Cycle intervals?

The fast cycles are the ones done at 2 amps charge and discharge - i.e. cycles 1-49. The 50th cycle is the one done with a slow 400 mA discharge.

 

[SoCalSteve]

Hi,

This is definitely a great resource you're sharing with the forum. Do you have any similar testing done for other battery manufacturers such as Powerex, Imedion, Ansmann, Amazon Basics (Black and White ones), etc?

Thanks.

 

[bcwang]

I noticed for the first 200 cycles or so, the Chinese Eneloops had more capacity? Was this due to being charged fuller due to termination behavior differences? (which may reduce cycle life). Or maybe having slightly higher capacity degrades their life cycle performance. (something possibly seen in the eneloop XX vs turnigy comparison.)

Were their discharge curves different? (voltage under load)

 

[Mr Floppy]

A good question that comes to mind is the fact that the IEC standard that is referenced on the back of the Eneloop packs would take around 18 months to get through 2100 cycles. How on earth have they managed to test the Chinese cells to that many cycles using that method when production in China has only been going for 12 or so months????

I'm guessing that the plant must have made cells for other brands for a while but other LSD brands that I've seen only rate 500 cycles.

I can only assume that Panasonic did not test the cells at all and just took all the blurbs from the last 4th gen Eneloop from FDK but not the technology. Mind you, the first gen Eneloops are not bad.

Were their discharge curves different? (voltage under load)

I'd like to know too.

 

[SimulatedZero]

I'm not going to lie, this does not sit very well with me at all. Damn, and I thought I had found the Holy Grail of deals on Amazon for rebranded Eneloop XX series. The batch that I got is all made in Japan, but who knows now.

A big thing to me though is the discharge curve. Like a couple of others have mentioned, I would like to see that plotted out on a graph for comparison.

 

[Power Me Up]

I noticed for the first 200 cycles or so, the Chinese Eneloops had more capacity? Was this due to being charged fuller due to termination behavior differences? (which may reduce cycle life). Or maybe having slightly higher capacity degrades their life cycle performance. (something possibly seen in the eneloop XX vs turnigy comparison.)

The Chinese Eneloops had more capacity at the start - you're quite possibly right that it is related to the reduced cycle life.

Were their discharge curves different? (voltage under load)

Good question!

I've done a couple of graphs up:

Both of the above graphs were done for the 3rd (2A) discharge for both cells - voltage under load was noticeably lower during the first discharge and improved a little with the 3rd discharge compared to the 2nd.

It's interesting to note that the Chinese Eneloop wasn't able to maintain the same voltage as the Japanese cell - although the Chinese Eneloop had more capacity, the total energy discharged at 2 amps was about the same. Internal resistance as measured on the charger for those discharges was 30 milliOhms for the Japanese cell and 50 milliOhms for the Chinese cell. IR varied a bit over the cycling, so there wasn't always that much difference between the IR of the 2 cells. At lower discharge rates, I would expect that the Chinese cell would pull ahead on Energy, but at higher currents, the test would favour the Japanese cell.

The above data was taken from the first pair of cells. I just took a look at the data from the second set of cells and the differences are actually bit smaller - to the point where the Chinese Eneloop has about 50mWh more energy than the Japanese cell - still a lower voltage under load, but less pronounced. The IR values are also closer at around 34 milliOhms and 45 milliOhms. I'm not sure of the reason for the differences - could be individual cell variations, or a bit more contact resistance on the first Chinese cell...

 

[Power Me Up]

I'm guessing that the plant must have made cells for other brands for a while but other LSD brands that I've seen only rate 500 cycles.

Assuming that it's not a new plant, either the Chinese made Eneloops are different than the other branded cells (in which case, those tests wouldn't be valid) or they're the same in which case they're no better than the other brand with an Eneloop badge slapped on to them!

 

[MidnightDistortions]

As I mentioned in my first post, they did show interest in my results and asked me to send them through...


A good response from Panasonic could have gone along the lines that they're concerned by my test results and are actively investigating what might have gone wrong - that would certainly inspire a bit more confidence than simply going silent!

Yeah, I never meant to say they were not interested, otherwise they would not have replied to have you show them what you found in your tests. They would have taken it seriously considering you found that the cycles are lower in the Chinese Eneloops.

There's some discussion of testing methods in the following thread:
http://www.candlepowerforums.com/vb/showthread.php?391756-Eneloop-XX-Vs-Turnigy-2400-Cycle-Testing

Basically, the IEC standard which they're claiming to use is based on (mostly) incomplete charge/discharge cycles and with no rest at all for most cycles. Charge/Discharge rates are also much lower than what I was using in my test. The IEC standard should take about twice as long to run as the test method that I have been using.

That would make sense considering XX Eneloops are rated at 500 cycles instead of under 200 in your test. I wonder what impact resting would do with each cycle allowing the battery to recover and cool down.

I would expect that it's more likely that the quality started lower and has been improved over time as the production process is fine tuned. Since both Chinese cells that I tested were from the same pack, it's possible that they came from a bad batch, or being from an early production run, it's possible that newer cells are capable of more cycles. I'm planning to run another test with at least one more Chinese cell that has been manufactured more recently.

Hmm, i'm curious what was the manufacturing date of the Chinese cells you tested? Most likely they would fine tune the errors made in the first batch but it depends on whether that this factory keeps quality control and eliminates manufacturing errors as they arise. And many may agree that the Chinese hasn't provided quality stuff, otherwise China wouldn't have such a bad reputation in quality control. I don't know if this applies to Panasonic Eneloops made in China or that you could be right, the first batch of Eneloops were of low quality and you may have tested one of the first production of Eneloops. Testing a more recently manufactured Chinese Eneloop might prove different results.

A good question that comes to mind is the fact that the IEC standard that is referenced on the back of the Eneloop packs would take around 18 months to get through 2100 cycles. How on earth have they managed to test the Chinese cells to that many cycles using that method when production in China has only been going for 12 or so months????

There's no way they would have been able to test the Chinese cells if the production for Eneloops in China was only around for 12 months. They might have estimated based on the Japanese tests. Then was Chinese manufactured Eneloops always rated at 65% remaining capacity when left in storage for 5 years?

It would be really interesting to know what is going on within Panasonic with regard to the Chinese production of Eneloops!

I think they ought to be more forthcoming if they really are concerned with the Chinese quality and want to give consumers the best in battery technology. With 500 cycles from the Chinese Eneloops you're still guaranteed roughly 5 years (provided they were well taken care of) and that might be stretched a bit longer depending on usage. But it also shows that the Japanese Eneloops will run longer in extreme conditions and will last longer overall. Your tests do prove that the Japanese Eneloops will last longer under extreme conditions and indeed the Chinese produced are not as reliable. Hopefully your testing will encourage Panasonic to look into the Chinese production and at the very least start putting quality control standards in the Chinese manufacturing plants equivalent to the Japanese plants.

 

[Mr Floppy]

Good question!

I've done a couple of graphs up:

Both of the above graphs were done for the 3rd (2A) discharge for both cells - voltage under load was noticeably lower during the first discharge and improved a little with the 3rd discharge compared to the 2nd.

Those two graphs remind me of the GP Recyko sag. I wonder ... possibly from the same plant?

 

[Power Me Up]

Hmm, i'm curious what was the manufacturing date of the Chinese cells you tested?

I just checked one of the cells and it has a code: "1405" stamped on the side - I'd assume that means May 2014.

Most likely they would fine tune the errors made in the first batch but it depends on whether that this factory keeps quality control and eliminates manufacturing errors as they arise. And many may agree that the Chinese hasn't provided quality stuff, otherwise China wouldn't have such a bad reputation in quality control. I don't know if this applies to Panasonic Eneloops made in China or that you could be right, the first batch of Eneloops were of low quality and you may have tested one of the first production of Eneloops. Testing a more recently manufactured Chinese Eneloop might prove different results.

At first, I was going to say that I can't have an early batch of Chinese Eneloops, but it looks like I'm possibly wrong about when production first moved to China: The earliest reference to Chinese made Eneloops that I can find is from late April this year, so I could well have cells from a (relatively) early batch.

Panasonic has been making NiMH cells in China for a while now - I found some speculation that the Chinese Eneloops are just rebadged Panasonic Evoltas. Maybe that's the case and they've just "uprated" the cycles that they're claiming and they are just the same (inferior) cells...

There's no way they would have been able to test the Chinese cells if the production for Eneloops in China was only around for 12 months. They might have estimated based on the Japanese tests. Then was Chinese manufactured Eneloops always rated at 65% remaining capacity when left in storage for 5 years?

Good question on the retention rating. They do claim on the packaging that it's based on IEC standard tests - I've haven't really looked at that part of the standard to see if it's accelerated or not...

I think they ought to be more forthcoming if they really are concerned with the Chinese quality and want to give consumers the best in battery technology. With 500 cycles from the Chinese Eneloops you're still guaranteed roughly 5 years (provided they were well taken care of) and that might be stretched a bit longer depending on usage. But it also shows that the Japanese Eneloops will run longer in extreme conditions and will last longer overall. Your tests do prove that the Japanese Eneloops will last longer under extreme conditions and indeed the Chinese produced are not as reliable. Hopefully your testing will encourage Panasonic to look into the Chinese production and at the very least start putting quality control standards in the Chinese manufacturing plants equivalent to the Japanese plants.

Absolutely - some transparency in all of this would be good IMHO.

I found a document on the web site of the Australian distributor of Eneloops:
http://www.master-instruments.com.au/files/news/eneloop_re_branding_document_august_2014.pdf.pdf

The third page has a comparison of the old 3rd gen Japanese cells to the 4th gen Chinese cells. Amongst other things, it's claimed that the Chinese cells work better in high temperature environments and that they work better in high drain devices. I don't know about the high temperature environments, but I feel quite confident in saying that I think that the Chinese cells are actually worse in high drain devices since they have higher internal resistance according to my measurements...

 

[Power Me Up]

Those two graphs remind me of the GP Recyko sag. I wonder ... possibly from the same plant?

I guess it's possible - I don't have enough info to be able to say confidently one way or the other though.

 

[mcnair55]

Well... The did show interest by asking for details about my testing method and for my results. Checking the last email that I received, it says that he would look at it early the following week - it doesn't actually say that he would respond though!

Good luck and hope they do respond but from experience company email has mega big b/s filters.Little tip leaned years ago,spell really badly as you get some jobs worth who cannot resist replying.

 

[Kestrel]

I have found the above test information (in the context of recent developments in mfg. location) very interesting, and being a big fan of the traditional Eneloops I am disappointed but not all that surprised.

I am reminded of the Duraloops episode ~4 years ago, when the white-top Duraloops (Japan mfg.) were phased out by the black-top Duraloops (China mfg.)
I'm reasonably sure we saw a similar change in performance?

Furthermore, another competitor at the time were the Rayovac LSD cells (called Hybrids IIRC?), they were China-mfg with similar substandard performance compared to the classic Eneloops.

If I was to venture a guess it would also be along the lines of the discussion above; there are manufacturing facilities in China that have been making this inferior iteration of LSD NiMH technology for a while now, and these cells have been going into the Rayovacs, the Duraloops after the changeover, and now finally our beloved Eneloops.

Thoughts?


Edit: This discussion did make me break down and finally order one of those Eneloop "Super Power Packs" from Amazon this morning. I know there isn't a certainty of me receiving the Japan-mfg cells at this point, but the longer I wait the chances of this will inevitably decrease as the supply chain is filled with the China-mfg cells.

 

[MidnightDistortions]

I just checked one of the cells and it has a code: "1405" stamped on the side - I'd assume that means May 2014.

At first, I was going to say that I can't have an early batch of Chinese Eneloops, but it looks like I'm possibly wrong about when production first moved to China: The earliest reference to Chinese made Eneloops that I can find is from late April this year, so I could well have cells from a (relatively) early batch.

Panasonic has been making NiMH cells in China for a while now - I found some speculation that the Chinese Eneloops are just rebadged Panasonic Evoltas. Maybe that's the case and they've just "uprated" the cycles that they're claiming and they are just the same (inferior) cells...

Good question on the retention rating. They do claim on the packaging that it's based on IEC standard tests - I've haven't really looked at that part of the standard to see if it's accelerated or not...

Absolutely - some transparency in all of this would be good IMHO.

I found a document on the web site of the Australian distributor of Eneloops:
http://www.master-instruments.com.au/files/news/eneloop_re_branding_document_august_2014.pdf.pdf

The third page has a comparison of the old 3rd gen Japanese cells to the 4th gen Chinese cells. Amongst other things, it's claimed that the Chinese cells work better in high temperature environments and that they work better in high drain devices. I don't know about the high temperature environments, but I feel quite confident in saying that I think that the Chinese cells are actually worse in high drain devices since they have higher internal resistance according to my measurements...

Again, great work here. It's a good theory that these particular Eneloops are rebrand Evoltas. It could be that they are attempting to increase the performance of them to function more like Eneloops using the Chinese to find out but i don't understand why they would or try to rebrand their Evoltas to Eneloops.

Didn't you mention in an earlier post somewhere that you do pay a lot for Eneloops? I'm curious on how much they charge you compared to Duracell, Energizer or the other brands carried in stores. Currently Duracells run at about $12.95 on Amazon. Energizer is $12.25 while Eneloops are sold for $13.79 which is a pretty good price considering both Energizer and Duracell are rated higher mAh, but they also have under 500 recharge cycles (and the Duracells are rebrand XX Eneloops). So there's really no competition here in America, the only thing that i wish is that they carried Eneloops at Best Buy or Target i think Costco is one of the only places, even though i haven't been to one in a long time. Otherwise i just order them from Amazon so hopefully they will continue to carry the Japanese brand. Keep fighting this long as there are Japan made Eneloops out there, there should be the option of getting them if they are well worth the cost for them. It's encouraging me to get some for family and friends that are into rechargeables but only have Duracells, Energizer or Rayovac brands.

 

[tilex]

First off, thank you for posting these test results. I wasn't even aware that Chinese-made Eneloops even existed until I found this post today. These results have me worried about the future availability of high-quality LSD NiMH cells.

A good question that comes to mind is the fact that the IEC standard that is referenced on the back of the Eneloop packs would take around 18 months to get through 2100 cycles. How on earth have they managed to test the Chinese cells to that many cycles using that method when production in China has only been going for 12 or so months????

Doesn't this support the theory that these Chinese Eneloops might be a previously-produced model of LSD cell that has been rebranded with an Eneloop label?

 

[Power Me Up]

Again, great work here. It's a good theory that these particular Eneloops are rebrand Evoltas. It could be that they are attempting to increase the performance of them to function more like Eneloops using the Chinese to find out but i don't understand why they would or try to rebrand their Evoltas to Eneloops.

It could be as simple as they think that since the Eneloop brand is fairly well recognised (at least compared to EVoltas) that using that brand will help them to sell more. Personally, I think that it's a very shorted sighted move and they could end up killing the Eneloop brand reputation quicker than it was originally built up...

Didn't you mention in an earlier post somewhere that you do pay a lot for Eneloops? I'm curious on how much they charge you compared to Duracell, Energizer or the other brands carried in stores.

"Normal" price for a pack of 4 Eneloops tends to be around AU$25 which is only a bit more than Energizer and Duracell rechargeables are often sold for here. Energizer and Duracells rechargeables rarely go on sale though whereas (Chinese) Eneloops are regularly going for $15 per 8 pack on special.