Project Farm's 7 year Eneloop update

[Schokokeks]

So, he just posted this (Timestamp takes you to the 7 year old daily cycling Eneloop):


It's STILL performing similar to new. The low resistance is absolutely amazing.

I know I saw some people recently wondering if Eneloops are worth paying extra for, and they absolutely blew their competition out of the water - after 7 years.

 

[PaladinNO]

I still haven't replaced any of my Eneloop or Eneloop Pro cells, but I am starting to question some of them.

It's either the cell(s) or my charger (Nitecore UMS4), because I was charging some cells this weekend due to issues with a Manker EH02 (single AAA headlamp), and I still don't know what the issue was. The light would turn on, cycle modes, turn off...and didn't want to turn on again without a physical tail cap disconnect / reconnect.
...Except with an Eneloop Pro.

Charging showed all at decent Voltage (1,35-1,39 V), but one cell (regular White Eneloop AAA) suddenly read 2,06 V, and got really hot to touch. Another showed high internal resistance (according to the UMS4). Guessing connection / correct cell registration issues with the charger, I threw all of them - 1x Pro and 2x regular - in an AA/AAA-only fast charger (GP Power V800C), let them charge fully, and suddenly all 3 cells worked fine in the Manker.

I got a Eneloop BQ-CC63 charger in a shopping cart right now, because this isn't the first time I am having issues with AA / AAA cells in the UMS4, but I don't think the fault lies with the Eneloop cells.

 

[dc38]

I still haven't replaced any of my Eneloop or Eneloop Pro cells, but I am starting to question some of them.

It's either the cell(s) or my charger (Nitecore UMS4), because I was charging some cells this weekend due to issues with a Manker EH02 (single AAA headlamp), and I still don't know what the issue was. The light would turn on, cycle modes, turn off...and didn't want to turn on again without a physical tail cap disconnect / reconnect.
...Except with an Eneloop Pro.

Charging showed all at decent Voltage (1,35-1,39 V), but one cell (regular White Eneloop AAA) suddenly read 2,06 V, and got really hot to touch. Another showed high internal resistance (according to the UMS4). Guessing connection / correct cell registration issues with the charger, I threw all of them - 1x Pro and 2x regular - in an AA/AAA-only fast charger (GP Power V800C), let them charge fully, and suddenly all 3 cells worked fine in the Manker.

I got a Eneloop BQ-CC63 charger in a shopping cart right now, because this isn't the first time I am having issues with AA / AAA cells in the UMS4, but I don't think the fault lies with the Eneloop cells.

I've only ever had 3 eneloops fail over the course of 10 years 2AAA and 1AA, that's 3/48. And I assume that the only reason they failed was because I overdischarged and trickled the AA in a solar lantern, and the 2AAA were repeatedly (accidentally) dropped in a minimaglite, and the abuse messed up the capacity retention. Anecdotally, with a 1/16 USER INDUCED failure rate over 10 years, that's a pretty reliable track record in my opinion.

**I have 16 white AA, 8 each light and dark blue AA, 4 each light and dark green AAA, and 8 white AAA.

 

[dc38]

I still haven't replaced any of my Eneloop or Eneloop Pro cells, but I am starting to question some of them.

It's either the cell(s) or my charger (Nitecore UMS4), because I was charging some cells this weekend due to issues with a Manker EH02 (single AAA headlamp), and I still don't know what the issue was. The light would turn on, cycle modes, turn off...and didn't want to turn on again without a physical tail cap disconnect / reconnect.
...Except with an Eneloop Pro.

Charging showed all at decent Voltage (1,35-1,39 V), but one cell (regular White Eneloop AAA) suddenly read 2,06 V, and got really hot to touch. Another showed high internal resistance (according to the UMS4). Guessing connection / correct cell registration issues with the charger, I threw all of them - 1x Pro and 2x regular - in an AA/AAA-only fast charger (GP Power V800C), let them charge fully, and suddenly all 3 cells worked fine in the Manker.

I got a Eneloop BQ-CC63 charger in a shopping cart right now, because this isn't the first time I am having issues with AA / AAA cells in the UMS4, but I don't think the fault lies with the Eneloop cells.

I've had decent performance out of an opus 3100 and an Xtar VC4. The Opus has settable currents in 200mA intervals up to 1A, and is NiMH/NiCd only. The VC4 can charged standard LiIons and NiMH/NiCd, with the outer bays charging UP to one amp each, or 500mA if either of the central bays are populated.

 

[PaladinNO]

I've only ever had 3 eneloops fail over the course of 10 years 2AAA and 1AA, that's 3/48. Anecdotally, with a 1/16 USER INDUCED failure rate over 10 years, that's a pretty reliable track record in my opinion.

I didn't mean to imply Eneloops are bad, it's what I swear by myself in terms of AA / AAA. And frankly, if the cell I referred to is damaged somehow, I am thinking it's the UMS4 that's the cause.

I started buying Eneloops back in 2011, and I haven't had a single one of them outright fail yet. But I have sold some lights with cells included, so the oldest ones may have left my care as I haven't kept my battery chart updated (or that detailed). So I don't really know how many Eneloops I currently have, but it should be in the 30's somewhere.

I've had decent performance out of an opus 3100 and an Xtar VC4. The Opus has settable currents in 200mA intervals up to 1A, and is NiMH/NiCd only. The VC4 can charged standard LiIons and NiMH/NiCd, with the outer bays charging UP to one amp each, or 500mA if either of the central bays are populated.

I keep a Xtar VC2 Plus Master at work, in addition to a Fenix ARE-C2 and the Nitecore UMS4 at home. Plus a Nitecore i2 as a backup.
I really like the charging amperage selector button on the VC2 - I can do the same with the UMS4, but it's a few more button presses. And I don't think the charger remembers the settings, I will have to check that. I prefer charging all my cells at lower amps, such as 0,5 A, regardless of cell type, for increased longevity.

 

[dc38]

I didn't mean to imply Eneloops are bad, it's what I swear by myself in terms of AA / AAA.

Ah, not at all, I was just sharing in your positive feedback, lol. 100% of my eneloop failures can be attributed largely to user error. In your case, it's entirely possible that the device was faulty and cooking the eneloop rather than eneloop failure

 

[Schokokeks]

I still haven't replaced any of my Eneloop or Eneloop Pro cells, but I am starting to question some of them.

It's either the cell(s) or my charger (Nitecore UMS4), because I was charging some cells this weekend due to issues with a Manker EH02 (single AAA headlamp), and I still don't know what the issue was. The light would turn on, cycle modes, turn off...and didn't want to turn on again without a physical tail cap disconnect / reconnect.
...Except with an Eneloop Pro.

Charging showed all at decent Voltage (1,35-1,39 V), but one cell (regular White Eneloop AAA) suddenly read 2,06 V, and got really hot to touch. Another showed high internal resistance (according to the UMS4). Guessing connection / correct cell registration issues with the charger, I threw all of them - 1x Pro and 2x regular - in an AA/AAA-only fast charger (GP Power V800C), let them charge fully, and suddenly all 3 cells worked fine in the Manker.

I got a Eneloop BQ-CC63 charger in a shopping cart right now, because this isn't the first time I am having issues with AA / AAA cells in the UMS4, but I don't think the fault lies with the Eneloop cells.

The BQ-CC17 is the one true charger. EVERY TIME someone has an issue with Eneloops, it turns out they're not using the BQ-CC17.

That BQ-CC63 might be okay, it's not listed as a "dumb" charger here:

The ultimate Eneloop charger list of 2026 (the best 5 + worst)

Complete Eneloop charger Guide: All Sanyo and Panasonic eneloop battery chargers produced between 2005 and 2026 (With the best Eneloop chargers)

eneloop101.com

The bad chargers essentially just use a timer, so avoid those at all costs.

Ironically, it seems like the fancier, Li-ion chargers try to "earn their" cost by charging Eneloops quicker, which seems to be where the issues arise. I've been using Eneloops now for...I don't even remember how long, and I haven't had a single cell go bad (and I've made some whoopsies with a few), but I religiously charge them with the BW-CC17. My flashlights are also like 90% AA or AAA, haha. I have probably well over 50 AA cells, haha.

 

[dc38]

The BQ-CC17 is the one true charger. EVERY TIME someone has an issue with Eneloops, it turns out they're not using the BQ-CC17.

That BQ-CC63 might be okay, it's not listed as a "dumb" charger here:

The ultimate Eneloop charger list of 2026 (the best 5 + worst)

Complete Eneloop charger Guide: All Sanyo and Panasonic eneloop battery chargers produced between 2005 and 2026 (With the best Eneloop chargers)

eneloop101.com

The bad chargers essentially just use a timer, so avoid those at all costs.

Ironically, it seems like the fancier, Li-ion chargers try to "earn their" cost by charging Eneloops quicker, which seems to be where the issues arise. I've been using Eneloops now for...I don't even remember how long, and I haven't had a single cell go bad (and I've made some whoopsies with a few), but I religiously charge them with the BW-CC17. My flashlights are also like 90% AA or AAA, haha. I have probably well over 50 AA cells, haha.

My eneloops seem to fare well when charged at a current of between 100 and 400 mA. The oldest ones I have are over 10 years old, and the charger still measures 1942mAh on average, with the most abused still functional one at 1862 and the highest one at 2049. That's a pretty tight delta for cells that are varying in age AND utilization.

 

[Schokokeks]

My eneloops seem to fare well when charged at a current of between 100 and 400 mA. The oldest ones I have are over 10 years old, and the charger still measures 1942mAh on average, with the most abused still functional one at 1862 and the highest one at 2049. That's a pretty tight delta for cells that are varying in age AND utilization.

Sure, but the cheapest option for Eneloop chargers is the best option, so take the free win when you can ;) hahah

I usually grab one with either the "starter kit" or 4 AA or AAA cells, as those usually are a decent deal. The D-cell adapters in the starter kit are great in 2-cell Maglite with an M31 droping.

 

[dc38]

Sure, but the cheapest option for Eneloop chargers is the best option, so take the free win when you can ;) hahah

I usually grab one with either the "starter kit" or 4 AA or AAA cells, as those usually are a decent deal. The D-cell adapters in the starter kit are great in 2-cell Maglite with an M31 droping.

I had one of those stock ones as it came in a kit, but charging time was in excess of 14 hours...so while I'm sure it is healthier for the cells (as I mentioned the range 100-400mA) I prefer the faster charging of 400mA...

I never could tell whether the stock charger was smart or dumb, but whether completely drained or barely drained, the charger would always take at least 14 hours to show solid green. Other users were reporting residual trickle charging in the 20's of mA years ago, as well, and that slow cooked their eneloops after a little while. I just blindly went with those anecdotal reports and haven't had any failures beyond the ones I believe I induced.

 

[Schokokeks]

I've never timed mine. I usually just put them in in the morning, and they're charged at some point when I walk by. They have a LOT of different chargers, so it all depends on which on you use.

I just keep spare cells about, put fresher ones in, recharge the low ones, then put them away. I love the braindead simplicity of it all, haha.

 

[Beacon of Light]

My eneloops seem to fare well when charged at a current of between 100 and 400 mA. The oldest ones I have are over 10 years old, and the charger still measures 1942mAh on average, with the most abused still functional one at 1862 and the highest one at 2049. That's a pretty tight delta for cells that are varying in age AND utilization.

Are you saying the Eneloop BQ-CC17 is worth buying if you have other smart chargers? I have a couple of Xtar chargers, a couple of Vapcell S4 V3 chargers, a few older Maha C9000s and even a couple of old LaCrosse BC700s.

 

[Beacon of Light]

I used to use my AAA and AA cells a bit more than I do now so they sit unused a bit longer than they used to. Using 14500, 18350, 18500, 18650 and 21700 cells more now. The past couple of weeks though I topped up some older mix of AAs, Old Kodak, Eneloops, and a Duraloop. They terminated the charge on my Liitokala M4S between 1.45-1.52v which seems normal. But is it normal to then sit a few days to a week at room temperature and when put back on the charger some were 1.3v. Should it discharge that much in a week of no use? This is the second time recharging them like this. Right now they've been charging at around 45 minutes at 300mA.

 

[Schokokeks]

Are you saying the Eneloop BQ-CC17 is worth buying if you have other smart chargers? I have a couple of Xtar chargers, a couple of Vapcell S4 V3 chargers, a few older Maha C9000s and even a couple of old LaCrosse BC700s.

Well, if you need another charger, it's a good one to have, and if you're going to get one, that's the one to get.

If you have a LOT of chargers, probably not.

BUT, the "starter kit" is pretty cool, and if it's under $50, it comes with AA, AAA cells, and then cool adapters, in a case - with the good charger.

 

[dc38]

Are you saying the Eneloop BQ-CC17 is worth buying if you have other smart chargers? I have a couple of Xtar chargers, a couple of Vapcell S4 V3 chargers, a few older Maha C9000s and even a couple of old LaCrosse BC700s.

I mainly employ my xtar vc4....I have since gifted the stock chargers with some of my eneloops lol. I just assumed that a non-enthusiast general-consumer charger was the safest to give away.

 

[TPA]

I've been using the C9000 / C9009 at home and a few BQ-CC87 and BQ-CC55 on the road. I find the Panasonic chargers to be pickier with older cells. With the Maha chargers I use 300mAh as the charge current.

I've recently started using the Xtar LC4 Pros and am trying to dig up my nastiest, oldest eneloop cells to throw at them and their Refresh mode. When (if?) life settles down, I do plan on doing some proper testing to see just how well this function works.

I have a bunch of lights which are brutal on AA/AAAs, usually causing regular alkalines to leak no matter which brand. They're not exactly kind to the eneloops either. These should be good for testing the Refresh modes.

 

[Beacon of Light]

Any idea if these cells are normal? I put the Eneloop and the old Kodak AA on the charger again today and they both terminated yesterday around 1.5v, and once on the charger, each one was 1.4v. They've been on for 15 minutes and just at 1.49v now. Should it be dropping that much in less than 12 hours with no use?

 

[linc90]

Any idea if these cells are normal? I put the Eneloop and the old Kodak AA on the charger again today and they both terminated yesterday around 1.5v, and once on the charger, each one was 1.4v. They've been on for 15 minutes and just at 1.49v now. Should it be dropping that much in less than 12 hours with no use?

Completely normal in my experience.

 

[Beacon of Light]

Completely normal in my experience.

I was hoping I'd be able to put them on the charger and it would show up as full or at least not take another hour to add another 270mAh. Is that a fake number? I'm charging at a low 300mA but am I gaining capacity every day, as it keeps adding about 200-300 mAh? How was it full less than 12 hours ago, and then today it sat on the charger for an hour and added 270mAh? Did it discharge that much mAh within the last 12 hours just sitting idle?

 

[linc90]

Did it discharge that much mAh within the last 12 hours just sitting idle?

White envelopes and equivalent quantity nimh self discharge much slower than that.

but am I gaining capacity every day, as it keeps adding about 200-300 mAh

You are simply overcharging the cell doing this. Due to the full charge behavior of the nimh chemistry, nimh chargers aways take considerable time to detect that an already full nimh cell is full, especially at low charge current relative to the cells capacity ( low c-rate is the correct term).