Eneloop Pro's going bad

LittleBill

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so i have prolly close to 100 standard white eneloops of various generations.

i have about 20 of the pro versions .

i purchased the pro's all around a year or 2, back a couple years back (sorry no date) unless you can tell me how to find it.

I am now noticing ALL of the pro versions having high resistance and some lights ld20 etc, can't even go into turbo mode.

anyone else seeing this? i have resistance reading almost into the 1000's with 400-700 being the norm, they prolly have less then 100 charges on all of them

NONE of my white standards are even close to this, all sit around 100-200 ohm's and work fine, all of which have the same charge cycle. lacross 900 with a discharge recharge at 500/1000ma.
 

tatasal

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I have the same observation as yours.

I never have 'regular' Eneloop (meaning 1,900mah) fail on me and all of them still have low IR, and this is on various generations.

But not with my Eneloop Pro, and even with my 16 Powerex Imedion 2400, some Duracell 2450...all, yes all, of them have failed by now.

I don't know if LSD niMh chemistry cells has problems with longevity when its capacity is raised beyond 2000mah?
 

Lynx_Arc

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I have a pair of duraloop pros (eneloops) that are fine so far but I haven't more than a half dozen cycles on them. I've heard that the pros don't get nearly as many cycles before they start to go bad but many like the tradeoff of extra capacity for less cycles. I've found one issue with all nimh batteries including eneloops is when you use the in sets in series you can end up reverse charging the lower capacity and/or weaker cells of the sets and it weakens them more and more till the start to have problems.
Maybe the pros don't handle charging at the same rates as the lower capacity eneloops.
 

tatasal

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I have a pair of duraloop pros (eneloops) that are fine so far but I haven't more than a half dozen cycles on them. I've heard that the pros don't get nearly as many cycles before they start to go bad

Actually the higher capacity Eneloop Pro are factory-rated at 'only' 500 cycles, way behind the 1,900mAh 'regular' Eneloops at 2,000 cycles, but nevertheless, my experience with the Pros are far from even less than a hundred and they already start to go bad.
 
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bigburly912

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Reckon it's pretty common. I had the same issues you are having. Started after around 20 cycles.
 

ChrisGarrett

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I won't buy hi-cap NiMH batteries any longer unless I need the extra capacity for some new device, which I don't currently have.

Chris
 

Lynx_Arc

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I've gone to using 18650s now when I find my duraloops can't keep up with the demand it is a lot easier to deal with and you can almost double your performance over them with 3400mah 18650s and less size and weight.
 

Grijon

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I am now noticing ALL of the pro versions having high resistance and some lights ld20 etc, can't even go into turbo mode.

anyone else seeing this?

AmazonBasic and Duracell both had what were accepted by the CPF community as being rebadged Eneloop Pros. I had 16 of each that I bought in the winter of 2014-15. Within 2 years every single one of them had gone bad. I charged them exclusively with a pair of Maha C9000s and they didn't have too many cycles on them.

Like you, I also have regular Eneloops that just don't seem to care what I do or don't do to them, they just keep soldiering on.
 
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MidnightDistortions

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A few questions, are they being charged to 100% then stored? If so that may contribute to the higher internal resistance. I would probably store them at 90% or less. You could always charge them up and use it temporarily in a device or discharge them until they take about 500-700mAh out.

The other question is how far are they discharged? The more they are discharged before recharging the more likely they'll die faster. An old Energizer or Duracell NiMH guide recommends charging the batteries when they have a resting charge of 1.23v (which is roughly 25% charge left). As I also use my high capacity LSD cells (Duracell AA, Eneloop Pro AAA) infrequently so far these are 2013-2014 batteries that still work fine with a low IR. Also I usually charge them at 600-700mA, but 500mA if they get discharged too low.
 

IonicBond

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I've got about 8 of the pros - I may treat them a bit more like the old conventional nimh's and see how they fare in a few years in regards to internal resistance.

The classic "Every 10 cycles, be sure to discharge to 1v (or 0.9v singly), and recharge.

I will also take just a *tad* off the top like you suggest when I store them - at say 90%, pulling maybe 250mah from them before storing longer than 2 weeks / month etc. That makes me want to research secondary reactions when stored fully charged and allowed to self-discharge (different chemical mechanism than that of a load).

I'll let you know, but thanks to this thread, the test starts!
 

MidnightDistortions

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Yeah, running some tests seems to be the best way to go. It's pretty weird how theres a lot of Eneloop Pro going bad after a few years from inconsistent use. I also wonder if heat is a factor, especially when you're recharging them regularly for a time and then stop. I use the C9000 when charging them as well. So automatically I can take them out when they read done in the charger instead of letting them do the 2 hour top off.
 

Grijon

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It stands to reason that everyone who has Pros going bad is treating them the same as they treat their regulars that aren't going bad; that's how it went for me, anyway, and those same regulars are still going strong years later. I'm not discouraging testing - I love test results! - just offering up more information.

Unrelated, Midnight, what starship is that in your avatar?
 
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MidnightDistortions

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archimedes made a point that perhaps constant heavy drain stresses the high capacity batteries which could be one of the problems people are having with the higher capacity Eneloop batteries. I noticed one of my AAA Eneloop Pro sets are not lighting up my new HP7 Coast light as good as the other one which have my other set. Going to swap the batteries to confirm this.

https://www.candlepowerforums.com/v...er-questions&p=5340423&viewfull=1#post5340423

Yep sure enough one of the sets are weaker. Noticed that the better set has a lower resting voltage of 1.24v, while starting out the weaker set was at 1.30v and dropped to 1.26v after being used in my new light. I wonder if an 1 amp recharge would revitalize the batteries.
 
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Grijon

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If you're willing to put the time in, a revitalization regime using your Maha could be:
1C charge and 1C discharge on Refresh & Analyze for a baseline
1/4C discharge
Break—In
1C discharge
1C charge and 1C discharge on Refresh & Analyze for comparison to baseline.

It would take a few days but give you some good information.

It's the Enterprise E from the Star Trek Next Gen movies starting with First Contact. 
I think the E was the most beautiful of the Enterprises :)
 

MidnightDistortions

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My better set of AAA Eneloop Pro was at 1.22v resting charge but when I charged them at 500mA they were already at 1.39v so took it to 2 amps and they got up to 1.47v within minutes and they got warm at the end indicating they were full (wasnt charging for very long) so I tossed them back in the light ran it for 10-15 minutes took a reading after letting them rest and they still showed 1.4v. (Now they're at 1.36v as I am typing this up) tossed them back into the light so I'll check them again as I use the light normally but so far it's shining bright.

I think the E was the most beautiful of the Enterprises :)

Definitely the best so far and seemingly almost as strong as the Defiant, even though the Enterprise D will always have a place. That was my favorite Enterprise until they destroyed it and built the E.
 

LittleBill

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If you're willing to put the time in, a revitalization regime using your Maha could be:
1C charge and 1C discharge on Refresh & Analyze for a baseline
1/4C discharge
Break—In
1C discharge
1C charge and 1C discharge on Refresh & Analyze for comparison to baseline.

It would take a few days but give you some good information.


I think the E was the most beautiful of the Enterprises :)


lacross refresh mode does this, i did 1A up 500ma down. it cycled prolly 15 times over 2 days, internal resistance got worse. and i always do a full discharge/recharge for all cells. the whites are in the 200ohm range and have longer shelf life between cycles.

let me be clear, most of the batterys can get back to full mah, they simply can't put out the amperage over a certain point.
 
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Grijon

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In a way I'm glad to hear that working with them doesn't bring them back; when mine went bad I just recycled them. Thanks for the info!
 

apagogeas

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I have 16 Panasonic eneloop pro (used in flashes 4 each time, around 40 cycles each) which I got back in early 2015. Its 4+ years now and they have lost only about 100-200mAh and all maintain a perfectly close resting voltage. Over the last year they have seen little use really but they hold up very well (LSD seems to be unaffected too). However, I just store them after a job without charging them, I may put some charge if they are very low but generally I avoid fully charging for storage which may have contributed to their current top condition. I fully charge them when I actually need them.
If your batteries turn out so bad, are you sure they are genuine?
 
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MidnightDistortions

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I figured out a way to get the IR lowered on the Eneloop Pro. At least 2 of my weak batteries can charge in the C9000 again.

What I did was nearly drain them out in my Coast HP7, the voltage was around 1.16v. They still had high IR so I charged them in my La Crosse charger. Didn't work at 400mA charge so I went to 1000mA and sure enough 3 minutes later I was able to charge them in my C9000 with the highest IR being 1.99v the lowest was 1.7v. I went and charged them at 2A but took them out once they got past 105F temps all batteries got about 350mAh. They got up around 1.44v and held 1.29v after a week of very minor use in the HP7. Started using the light this weekend and sure enough 2 of the batteries are under 1.9v. The other 2 was around 2.15v but I'm sure that a second treatment of discharge/recharge at 2A will remedy the other 2 cells. They were originally at 2.40v IR so normal use and very high recharge seems to revitalize them.
 
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