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Interceptor121

Life span of Eneloop Pro Batteries

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I have just binned 12 of my Eneloop pro batteries all made in 2017 up until 2/19

Eneloop pro do not have the same life span of standard eneloop and are limited to 500 cycles however once you get to 3 years you will notice that your strobe will take much longer to fully recharge

It will give ready to fire signal pretty much in the same time but in order to have a full dump once the battery has aged this may become a much longer time

For reference sea and sea YS-D2 new batteries c1.5 seconds. Well used batteries around 2.2 seconds

Standard eneloop can last up to five years instead performance to ready is again similar to full longer than an eneloop pro but a 3 years old eneloop will do better than a 3 years old eneloop pro

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Interesting! Thanks for that. Food for thought......

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That seems to be true.  The issues with pros have been discussed for a few years now on a place called candlepower forums.  A lot of those folks are hardcore battery nerds, so reading the threads can be a slog for the rest of us, but there are numerous discussions about the shorter life of the extra-capacity eneloops.  Some of those folks suggest that factors adding to a generally shorter lifespan include improper storage (heat, humidity, storing with a 100% charge),  the prevalence of counterfeit eneloops (I only buy from reliable sellers), improper charging causing damage, and perhaps most importantly, running them down to dead or almost dead before charging.

I am unsure how much benefit the pros offer in uses such as camera flashes.  I have assumed they provide shorter recycling, and/or perhaps more flashes per charge, but possibly there is no real benefit.

Be aware also that many of the chargers that one can buy for these batteries will indicate a full charge even though the batteries have only reached 80-90% and then the  charger has gone into a trickle mode, taking several more hours to fully charge and with no further indication that the batteries are now fully charged.

The first time I used my new Retras, I had significant battery issues.  I added superchargers since then but also learned that my charger was doing as described above and have changed my travel charger.  There are charger testing and review sites that describe which chargers do this.

Some useful eneloop info:

https://eneloop101.com/batteries/eneloop-pro/

https://www.panasonic.com/global/energy/products/eneloop/en/faq.html

Actually, I just looked around on the eneloop 101 site and found this:

 

Test 1: Total amount of pops per set of batteries (average between 2 flash units):

Powerex 2700 Pro:Average: 400.5
Eneloop 2450 Pro: Average: 386.5
Powerex 2600: Average: 380.5
Powerex 2700: Average: 371.5
AmazonBasics 2400: Average: 359.5
EBL 2800: Average: 331.5 7
Duracell 2450: Average: 297.5
Eneloop White 1900:Average: 294.5

The 300th Pop recycle time in seconds (faster is better)

  1. Eneloop 2450 mAh Pro @ 2.5 sec
  2. Powerex 2700 mAh Pro @ 2.7 sec
  3. Powerex 2600 mAh @ 2.9 sec
  4. AmazonBasics 2400 mAh @ 3.5 sec
  5. Eneloop White 1900 mAh @ 3.6 sec
  6. EBL 2800 mAh @ 4.2 sec
  7. Powerex 2700 mAh @ 5.8 sec
  8. Duracell 2450 mAh @ 10.2 sec
Edited by Draq

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4 minutes ago, Draq said:

That seems to be true.  The issues with pros have been discussed for a few years now on a place called candlepower forums.  A lot of those folks are hardcore battery nerds, so reading the threads can be a slog for the rest of us, but there are numerous discussions about the shorter life of the extra-capacity eneloops.  Some of those folks suggest that factors adding to a generally shorter lifespan include improper storage (heat, humidity, storing with a 100% charge),  the prevalence of counterfeit eneloops (I only buy from reliable sellers), improper charging causing damage, and perhaps most importantly, running them down to dead or almost dead before charging.

I am unsure how much benefit the pros offer in uses such as camera flashes.  I have assumed they provide shorter recycling, and/or perhaps more flashes per charge, but possibly there is no real benefit.

Be aware also that many of the chargers that one can buy for these batteries will indicate a full charge even though the batteries have only reached 80-90% and then the  charger has gone into a trickle mode, taking several more hours to fully charge and with no further indication that the batteries are now fully charged.

The first time I used my new Retras, I had significant battery issues.  I added superchargers since then but also learned that my charger was doing as described above and have changed my travel charger.  There are charger testing and review sites that describe which chargers do this.

Some useful eneloop info:

https://eneloop101.com/batteries/eneloop-pro/

https://www.panasonic.com/global/energy/products/eneloop/en/faq.html

 

 

From what I understand the eneloop pro have higher capacity and higher discharge current

So a set of new pro should charge a strobe quicker than standard ones

However after one year that Pro has dropped to 85% charge so it is now 2125 mAh while the standard will be sitting at 1900 mAh for a long time. In 2-3 years the pro becomes worse than a standard

however I am personally after peak performance and am ok to buy batteries again every 3 years

I need to test the real charging speed when I get a new set of both

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The official data are:

Eneloop pro AA: 2500 mAh; 500 cycles

Eneloop AA: 1900 mAh; 2100 cyles

=> After first exclusively using Pro, I had repeated accu failures when on diving holidays. Therefore I switched to the regular Eneloops and have considerably less failures nown (maybe flash charging is a little bit slower, but I never realized it in practice)...

 

Wolfgang

P.S.: When an accu (pro or regular) makes problems while loading on the fast charger I have with me on holidays, I separate it from the rest (I always have spares with me), revitalize it fully at home with my Ansman charger and use it for other items, e.g. remote controls at home...

 

 

Edited by Architeuthis

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1 hour ago, Draq said:

That seems to be true.  The issues with pros have been discussed for a few years now on a place called candlepower forums.  A lot of those folks are hardcore battery nerds, so reading the threads can be a slog for the rest of us, but there are numerous discussions about the shorter life of the extra-capacity eneloops.  Some of those folks suggest that factors adding to a generally shorter lifespan include improper storage (heat, humidity, storing with a 100% charge),  the prevalence of counterfeit eneloops (I only buy from reliable sellers), improper charging causing damage, and perhaps most importantly, running them down to dead or almost dead before charging.

I am unsure how much benefit the pros offer in uses such as camera flashes.  I have assumed they provide shorter recycling, and/or perhaps more flashes per charge, but possibly there is no real benefit.

Be aware also that many of the chargers that one can buy for these batteries will indicate a full charge even though the batteries have only reached 80-90% and then the  charger has gone into a trickle mode, taking several more hours to fully charge and with no further indication that the batteries are now fully charged.

The first time I used my new Retras, I had significant battery issues.  I added superchargers since then but also learned that my charger was doing as described above and have changed my travel charger.  There are charger testing and review sites that describe which chargers do this.

Some useful eneloop info:

https://eneloop101.com/batteries/eneloop-pro/

https://www.panasonic.com/global/energy/products/eneloop/en/faq.html

Actually, I just looked around on the eneloop 101 site and found this:

 

Test 1: Total amount of pops per set of batteries (average between 2 flash units):

Powerex 2700 Pro:Average: 400.5
Eneloop 2450 Pro: Average: 386.5
Powerex 2600: Average: 380.5
Powerex 2700: Average: 371.5
AmazonBasics 2400: Average: 359.5
EBL 2800: Average: 331.5 7
Duracell 2450: Average: 297.5
Eneloop White 1900:Average: 294.5

The 300th Pop recycle time in seconds (faster is better)

  1. Eneloop 2450 mAh Pro @ 2.5 sec
  2. Powerex 2700 mAh Pro @ 2.7 sec
  3. Powerex 2600 mAh @ 2.9 sec
  4. AmazonBasics 2400 mAh @ 3.5 sec
  5. Eneloop White 1900 mAh @ 3.6 sec
  6. EBL 2800 mAh @ 4.2 sec
  7. Powerex 2700 mAh @ 5.8 sec
  8. Duracell 2450 mAh @ 10.2 sec

Thanks for that table

I think that if you use new pro those values will stand however after they are worn out and aged I am not sure anymore

The white are really slow consistent with some earlier observations a few years ago

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I tend to replace the pro batteries every few years.  Compared to the other costs of dive/travel photography, it is a minor expense.  When i am done with them I take them to a lithium battery recycling drop off point.

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Has anyone been able to find the internal impedance specs for the Eneloop standard vs. the Eneloop Pro batteries?  That will give us a better idea of which battery should have the faster recycle time.  The lower the internal impedance the better.  For example, the Powerex Pro have an internal impedance of 25 milliohms.

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1 hour ago, 200_SS said:

Has anyone been able to find the internal impedance specs for the Eneloop standard vs. the Eneloop Pro batteries?  That will give us a better idea of which battery should have the faster recycle time.  The lower the internal impedance the better.  For example, the Powerex Pro have an internal impedance of 25 milliohms.

As the battery ages internal resistance increases. So as explained here straight off the packet a set of Pro will beat standard on all fronts

However after 500 cycles or 3 years the pro will be dead beat while the standard will be still going

As underwater strobe users fast recycling time is more important than saving £ per year so there is no much point getting standard batteries

I use standard for wireless keyboard and mouse

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5 minutes ago, Interceptor121 said:

I use standard for wireless keyboard and mouse

LOL, that's what happens to my old strobe batteries. Although I see the new Apple Studios have a built in rechargeable battery.

I also put the old Eneloops in my dive torch. They're good for a dive or two.

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On 9/6/2022 at 2:50 PM, TimG said:

LOL, that's what happens to my old strobe batteries. Although I see the new Apple Studios have a built in rechargeable battery.

I also put the old Eneloops in my dive torch. They're good for a dive or two.

I just put in the YS-D2 the eneloop pro bought in 2020 and the standard bought in 2019

Set the timelapse for 4 shots with 2 seconds interval both shoot full charge not possible to determine what is quicker

So at this point I would say pro 2 years old and standard 3 years old match and keep the advice of ditching the pro at max 3 years

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I had one eneloop pro die last weekend. It was one of 8 I have been using in two Inon 220s this summer. It registered as HIGH when I put it in my battery analyzer (discussed here before). The other 7 were OK i.e. not HIGH when I analyzed them. With our continuing deluge (so no chance of photography as my local lake is about 1 meter above normal) I decided to put them on the analyzer today - 3 of the remaining 7 were HIGH! I had three good shoots this week (consecutive days with sunshine and just a few clouds) so they did get some heavy use (> 2000 shots/day). As they were fully charged I put them in a three-cell Inon light and the light works. So they are not fully dead but likely not reliable enough for strobes. These pros are dated 2018 so past the 3-year limit.

I have 8 more pros. One group of 4 scored 2.2+ Ah while the other 4 scored 2.3+ Ah (about a 50 mAh range for each group) this week (analyzed them after the first one went HIGH). These have not been used for about 2 years so they may not go down as fast if not used. I may switch to them if more of the remaining 4 score HIGH. All 16 were bought at the same time to use with my two original Retras per Retra's recommendation.

Edited by Tom_Kline

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6 minutes ago, Tom_Kline said:

I had one eneloop pro die last weekend. It was one of 8 I have been using in two Inon 220s this summer. It registered as HIGH when I put it in my battery analyzer (discussed here before). The other 7 were OK i.e. not HIGH when I analyzed them. With our continuing deluge (so no chance of photography as my local lake is about 1 meter above normal) I decided to put them on the analyzer today - 3 of the remaining 7 were HIGH! I had three good shoots this week (consecutive days with sunshine and just a few clouds) so they did get some heavy use (> 2000 shots/day). As they were fully charged I put them in a three-cell Inon light and the light works. So they are not fully dead but likely not reliable enough for strobes. These pros are dated 2018 so past the 3-year limit.

I have 8 more pros. One group of 4 scored 2.2+ Ah while the other 4 scored 2.3+ Ah (about a 50 mAh range for each group) this week (analyzed them after the first one went HIGH). These have not been used for about 2 years so they may not go down as fast if not used. I may switch to them if more of the remaining 4 score HIGH. All 16 were bought at the same time to use with my two original Retras per Retra's recommendation.

Not sure about your score 2.2 over 2400 mAh is not a great loss however what about the peak current?

Lights will not drain lot of instantaneous power they are not like strobes which are more demanding on charge current

The other thing to consider I bought the batteries in Feb 2020 however the production date was 7/19 this is another thing that bugs me I need to find a supplier that has more stock turnover than amazon

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The score is what one gets from the PowerX Analyzer (no point in using the mili prefix IMHO). It should be the actual capacity but the max it can deliver in current is unknown. I was using the Inons at very low settings -4 and -4.5 so the batteries were not being stressed for recycling but I did shoot a large number of pix. Strobe setting varied as well as lens aperture, either f/18 or f/20, using the EMWL. Still dialing this in for my conditions - ambient light is going down. Mainly was trying to avoid blown highlights as salmon have white parts as well as reflective scales.

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I have some new information that I have gathered directly from Panasonic website which I think is rather worrying for some underwater users

https://www.panasonic-eneloop.eu/en/faq/how-increase-battery-life

https://www.panasonic-eneloop.eu/en/faq/how-use-battery-properly

https://www.panasonic-eneloop.eu/en/faq/how-discharge-battery

The last point is bothersome Another way is to put a battery in a flashlight or other device and let it stay on until the battery is empty. Do note that we do not recommend this method, as it may cause over discharge and shorter battery life. 

My interpretation of the last point is that draining the batteries is not helping their life.

Note also the suggestion of not mixing batteries purchased on different dates

The other interesting part is that Panasonic sells their own charger that can refresh and diagnose the eneloop

https://www.panasonic-eneloop.eu/en/chargers/bq-cc65-plastic-free-charger-pack

Although taking this on a trip can be bulky it is an item to have to check your batteries before the trip I just bought one myself 

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I just bought 16 Eneloop Pro batteries and 2 of the Panasonic BQ-CC55KSBHA Advanced eneloop pro Rechargeable Battery 4 Hour Quick Chargers. I am hoping that the Eneloop chargers are better because they are specifically designed for the the maintenance of the batteries:
“This charger is optimized for charging eneloop and eneloop pro AA and AAA rechargeable batteries”

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I just bought 16 Eneloop Pro batteries and 2 of the Panasonic BQ-CC55KSBHA Advanced eneloop pro Rechargeable Battery 4 Hour Quick Chargers. I am hoping that the Eneloop chargers are better because they are specifically designed for the the maintenance of the batteries:
“This charger is optimized for charging eneloop and eneloop pro AA and AAA rechargeable batteries”

I just bought 16 Eneloop Pro batteries and 2 of the Panasonic BQ-CC55KSBHA Advanced eneloop pro Rechargeable Battery 4 Hour Quick Chargers. I am hoping that the Eneloop chargers are better because they are specifically designed for the the maintenance of the batteries:
“This charger is optimized for charging eneloop and eneloop pro AA and AAA rechargeable batteries”

From what I understand the Panasonic chargers use a fairly low charging current max 600 mA
Some of the quick chargers can give a much higher current resulting in a shorter battery life
The other part that seems important is to avoid the batteries to go flat in the strobes as that may mean a refresh cycle that almost no charger can give properly
I have not toasted a strobe yet but am worried about all those unknown (to me) limitations


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On 9/17/2022 at 10:58 PM, UWPics said:

I just bought 16 Eneloop Pro batteries and 2 of the Panasonic BQ-CC55KSBHA Advanced eneloop pro Rechargeable Battery 4 Hour Quick Chargers. I am hoping that the Eneloop chargers are better because they are specifically designed for the the maintenance of the batteries:
“This charger is optimized for charging eneloop and eneloop pro AA and AAA rechargeable batteries”

The BQ-CC55 is a good and fast charger.  As with many fast chargers, it is a little harder on the batteries and that might reduce their overall lifespan, but that is probably not worth worrying about too much.  One thing to know about the BQ-CC55 is that it uses a top-off charge, meaning that when the green light goes on, the batteries are around 80-90% charged, but not full.  The charger switches into a much lower, almost trickle charge rate and the batteries are not really full for one to two more hours.  At that time the charger lights go  off.

Two things can extend the life of the eneloops.  Don't fully discharge them.  Like many modern batteries, they don't like being drained and it will shorten their life span or possibly render them unable to accept a charge except from more sophisticated chargers.  Also, if they are to be used intermittently,  store them partially charged and only charge them before use.  Charging them fully before storage shortens their life.  There is a reason Panasonic ships these at 85% charge.

FWIW, after much research, I have started using these to charge eneloop pros during travel:

https://www.xtar.cc/product/XTAR-BC8-Charger-190.html

it is simple to use, but a smart charger.  It charges the batteries to 100% without using a trickle or top-off charge.  The charger is only slightly larger than a 4-cell Panasonic charger and two BC8 chargers take less room and weigh less than 4 of the four-cell chargers.  Also, depending on where I travel, it can sometimes be difficult to find four available electrical outlets.  If I were not using Retras with superchargers, I might just use 2 of the smaller four-cell chargers.  The BC-8 is probably slightly slower to charge 8 batteries than two of the BQ-CC55 chargers would be.

 

Edited by Draq

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I've been using this model charger for a long time and I have batteries that are 10 years old which are still going - they get used in my torches, it offers a choice of 1.0A or 0.5A charging rates.  My standard approach for many years was to keep using batteries in my land flashes till they stopped charging and swap them over, these batteries still seem to have adequate capacity.  These cells were Imedions and prior to that I had some that were labelled e-lock an early eneloop clone.  They still run my torch for 2 x 1 hr dives quite readily.

https://mahaenergy.com/mh-c800s/

I don't use those cells  in my UW strobes as a rule and have been using eneloop/eneloop pro and running them to empty is not a practical option for UW work anyway.  The point is the charger must be doing something right as the cells are surviving and still performing just fine.  My Eneloop pro have a manufacturer date of 2018 and still can do at least 2 dives.  They normally get used for a local double dives a couple of times per month and are recharged after the dive.

 

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I have been in correspondence with Panasonic energy and I have asked them about the production date

The answer has been the batteries themselves last around 10 years so you should not worry too much about the production date. The life is influenced by the number of cycles which are 500 for the Pro and 2100 for the standard ones

So as long as you do not drain them a standard eneloop has more than 4x the life of a Pro.

Generally I doubt that someone doing 4 trips per year with two strobes say around 100 dives will do more than 100 cycles in the two battery sets it has. So each battery should have 50 cycles and last for a long period of time including the pro

So any premature death is either extensive use or bad practices

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44 minutes ago, Interceptor121 said:

I have been in correspondence with Panasonic energy and I have asked them about the production date

The answer has been the batteries themselves last around 10 years so you should not worry too much about the production date. The life is influenced by the number of cycles which are 500 for the Pro and 2100 for the standard ones

So as long as you do not drain them a standard eneloop has more than 4x the life of a Pro.

Generally I doubt that someone doing 4 trips per year with two strobes say around 100 dives will do more than 100 cycles in the two battery sets it has. So each battery should have 50 cycles and last for a long period of time including the pro

So any premature death is either extensive use or bad practices

I fully agree, "So any premature death is either extensive use or bad practices", but want to add that the conditions, how we charge our accus when on a trip, are suboptimal and "bad practice" is unavoidable. Often the current is coming from a generator and not from the regular line, this causes problems. I think the 500 vs. 2000 cycles (pro vs. regular) do not apply for UW-photography conditions and in reality the lifetime is much shorter:

I do not track the lifespan of the single cells, but the experience is that when my wife and me take 28 AA Eneloops (mostly regular white ones; we have 5 strobes together) with us for a 2-3 week diving trip, in average 1-3 of them are recognized as bad on the regular BQ-CC55 charger under these conditions during the trip. I sort them out and regenerate them at home with the "good" Ansmann charger (I cannot remember that the regeneration program ever failed with a single cell, this must be very seldom the case). These cells are not recycled for UW-photography, instead they go to e.g. remote controls at home. Over the last six years, we have sorted out most of our Pro cells this way, while there have been only few regular (white) cells that had to be excluded. I doubt that recycled Pro cells will have a charging advantage over fully intact regular cells...

=> The reason why I renew our stock now exclusively with white Eneloops, is not that I want to save (very little) money on the cost of (a little) charging time, but I intend to get more reliability during the diving trips...

 

Wolfgang

Edited by Architeuthis

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42 minutes ago, Architeuthis said:

I fully agree, "So any premature death is either extensive use or bad practices", but want to add that the conditions, how we charge our accus when on a trip, are suboptimal and "bad practice" is unavoidable. Often the current is coming from a generator and not from the regular line, this causes problems. I think the 500 vs. 2000 cycles (pro vs. regular) do not apply for UW-photography conditions and in reality the lifetime is much shorter:

I do not track the lifespan of the single cells, but the experience is that when my wife and me take 28 AA Eneloops (mostly regular white ones; we have 5 strobes together) with us for a 2-3 week diving trip, in average 1-3 of them are recognized as bad on the regular BQ-CC55 charger under these conditions during the trip. I sort them out and regenerate them at home with the "good" Ansmann charger (I cannot remember that the regeneration program ever failed with a single cell, this must be very seldom the case). These cells are not recycled for UW-photography, instead they go to e.g. remote controls at home. Over the last six years, we have sorted out most of our Pro cells this way, while there have been only few regular (white) cells that had to be excluded. I doubt that recycled Pro cells will have a charging advantage over fully intact regular cells...

=> The reason why I renew our stock now exclusively with white Eneloops, is not that I want to save (very little) money on the cost of (a little) charging time, but I intend to get more reliability during the diving trips...

 

Wolfgang

This is a valid point however the power supply should be able to manage a good DC output to the charger even if the input is fluctuating as it is an AC DC converter

I use USB chargers so I can actually power them with a power supply that is regulated or a powerbank

For what concerns batteries that are recognised as bad during the trip there are several possibilities

1. You mixed batteries in the strobe from different ageing and batches

2. The batteries got too hot

3. The batteries were drained and could not revive using the charger

4. other things I cannot think about....

For me the single most dangerous thing for a battery is heat this can happen in the strobe but also in the charger if the charging current is too high. The eneloop chargers have a fairly low charging current but some fast chargers can delivery 1A to a small AA and that in due course may fry the battery if there is insufficient ventilation, the enviroment is hot etc etc

I will continue with some experiments this week processing some 2017 batteries with the eneloop pro charger to see what it says. I have disposed of those batteries for regular use underwater but they still work technically

With regards to white vs black eneloop the initial capacity of 1900 mAh vs 2500 mAh means that you can get less flashes out of regular eneloop which in turn means more likely they will drain out

I am surprised you get fauly whites I use those for keyboards and mouses since many years. The reason why Panasonic recommends eneloop pro for flashes is that they tolerate higher discharge current at the cost of shoter life. The white ones will recycle slower and potentially also die sooner than 2000 cycles

Edited by Interceptor121

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5 hours ago, Architeuthis said:

I fully agree, "So any premature death is either extensive use or bad practices", but want to add that the conditions, how we charge our accus when on a trip, are suboptimal and "bad practice" is unavoidable. Often the current is coming from a generator and not from the regular line, this causes problems. I think the 500 vs. 2000 cycles (pro vs. regular) do not apply for UW-photography conditions and in reality the lifetime is much shorter:

I agree with Massimo, most chargers should be able to cope with current variations as they have a multi voltage electronic inverter to produce a stable DC output.  Maybe I'm a light user but I've not encountered difficulties with Eneloop or Eneloop style strobe batteries and Like I said for land use I run them empty and they'll generally do 3 dives on my Z-240s so I can generally soft charge them at 0.5A on my Maha charger which is what I travel with.

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I agree with Massimo, most chargers should be able to cope with current variations as they have a multi voltage electronic inverter to produce a stable DC output.  Maybe I'm a light user but I've not encountered difficulties with Eneloop or Eneloop style strobe batteries and Like I said for land use I run them empty and they'll generally do 3 dives on my Z-240s so I can generally soft charge them at 0.5A on my Maha charger which is what I travel with.

Interestingly Panasonic recommends charging the battery between 0.5 and 1C which means 1250 to 2500 mA a fairly high current. However their own charger works at 600 mA
The trickle charge mechanism is actually good as it avoids overcharging the batteries when they are left in the charger and also avoids heating them up more than required
In terms of storage eneloop recommendation is actually to store the batteries fully charged if you are not going to use them for a while. This is different from lithium batteries that are stored at 20-25%


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8 hours ago, Interceptor121 said:


The trickle charge mechanism is actually good as it avoids overcharging the batteries when they are left in the charger and also avoids heating them up more than required
 

Everything I have read and heard on the battery nerd forums and test sites suggests that using a top-off or trickle charge method is not ideal for charging LSD batteries.  I am not a battery geek, so I may have the terminology wrong, but with LSD batteries, chargers cannot easily determine when a full charge has occurred if the charge rate is too low (Below 500 - 1000 mA).  When chargers rely on a top-off or trickle charge for the last 20%, there is a likelihood of overcharging, so many of these chargers have to rely on a timing mechanism instead of assessing a 100% charge. I believe the BQ-CC55 shuts off after 1 hour.  LSD batteries are sensitive to overcharging and doing so will shorten their lifespan and can cause other problems.  So the ideal way to charge LSD batteries is to supply a sufficient charge  until the battery is at 100% and then terminate the charging.   This assures a full, but not overcharged battery.  That is not how all the Panasonic chargers work.

image.png.5e708646d5a79ff24af351ac9112c02c.png

The BQ-CC55 "uses a -dv/dt termination and has a 1 hour top-off charge at around 140mA.... as can be seen on the temperature the cell is full and get stuffed a bit extra with the top-off charge. "

 

The BQ-CC17, in contrast to the B-CC55, charges to 100% and then stops.  But is a much slower charger:

image.png.71d73729827046117def79d98591cdf7.png

Again, I am relying on what others have told me, including testing and opinions (and the attached graphics) found at https://lygte-info.dk/

On this page (https://lygte-info.dk/info/batteryChargingNiMH UK.html )  is one of the clearer explanations of what I am saying: 

"AA/AAA NiMH batteries are usual rated for charging up to 1C, i.e. same current as their capacity. This means that a charge current of 2000mA (or 2A) for a 2000mAh battery, most chargers will charge with a lower current, but there is also some chargers that uses higher current.  A high charge current will usual reduce the number of charge cycles a battery can last, i.e. using a lower charge current will mean longer battery life.  But using a low charge current has its own problems, detecting when a NiMH battery is full can be problematic and overcharging will also reduce the life of the battery, especially LSD (Low Self Discharge) types.

One way around this problem is using the battery voltage for termination, it works, but has a few problems because it varies with temperature and actual chemical composition of the battery, i.e. not all brands needs exactly the same termination voltage. If the termination voltage in the charger is a too high the charger may never terminate and will overcharge the battery in a serious way. If the termination voltage is too low, the charger will stop premature and you will get a battery with a bit less than full capacity. This can be fixed with a top-off charge, i.e. a lower current charge for a fixed time (like 1-2 hours), this will probably overcharge the battery, but with a low current and for a limited time, i.e. damage will be minor."

 

His concluding statement includes "To get a good charger look for one with individual cell termination, i.e. it must be able to charger one cell at a time. It must terminate when the battery is full and preferable not use trickle charge. For chargers with voltage termination a top-off charge is acceptable and secures that the cell is full, for chargers with -dv/dt termination it is not needed."

So, I prefer a charger that charges to 100% at a reasonable rate of charge, and then terminates, but a charger like the BQ-CC55 is a good alternative due to its speed, and for most of us, a possible slight reduction in battery life is an acceptable trade-off.  I would not hesitate to use them on a dive trip.  However, the thread topic is lifespan of eneloops, so the point of increased lifespan is germane. 

Note:  I also obtained some information from a very close family member who, as it happens, is an engineer for Panasonic Energy.

Oh, and one last point.  NIMH LSD batteries should not be "left in the charger."  This may explain some of your lifespan issues.  Take them out when they are done and store them out of the charger.

 

 

 

Edited by Draq
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