Is memory effect a serious concern for NiMH batteries?

ksio89 · 2018-08-03T21:24:12.000Z

I knew that nickel-cadmium batteries might suffer from memory effect if they are repeatedly recharged after being only partially discharged. However, after doing some research, I found out that nickel metal hydride batteries may also suffer from this. I have got a couple of genuine Eneloop batteries, which were very expensive, so I would like them to live as long as possible. Besides these batteries, I own a Panasonic BQ-CC17 smart charger, which is a good albeit slow charger according to a review by HKJ, thus I suppose it will contribute to extend my batteries longevity. For the experts here on BLF, would anyone be able to tell me if memory effect is a real concern for NiMH batteries? If so, are there any recommendations to lessen it? Thanks in advance.

Pete7874 · 2018-08-03T21:27:18.000Z

Short answer, no.

Lightbringer · 2018-08-03T22:48:42.000Z

Yeah, not even serious, largely nonexistent.

ChrisGarrett · 2018-08-03T22:52:53.000Z

Use ’em and abuse ’em.

Space aliens are a bigger concern.

Chris

NeutralFan · 2018-08-04T00:57:54.000Z

Agreed. From experience and from what I’ve read here, it seems the eneloop batteries are pretty much bullet proof.

ksio89 · 2018-08-04T14:11:35.000Z

Thanks for the replies, guys. Glad to know Eneloop batteries last very long when paired with a good charger.

gadabout · 2018-08-05T06:22:41.000Z

Probably worth adding that you should try to keep them in matched sets if you use them in series, especially in the 4-cell soda can type lights or other electronics. They are very robust but can be damaged by reversal if you pair an older cell with 3 new ones for instance, or if you put them in at different states of charge.
I use a MAHA C9000 to glance at the approximate amount of charge each cell takes. If I see one becoming vastly different from the others I’ll separate it and run a break-in cycle.

My Eneloops have been rock solid going all the way back to 2006. Some of my Imedion Powerex 2300s are getting a bit flakey. Mostly self-discharge issues. I think a few of them should be culled.

Other various cheapies are all over the place in terms of capacity and self-discharge. I don’t put them in anything critical.

The IKEA Laddas (White and the older greens) have been performing well so far.

teacher · 2018-08-05T10:29:32.000Z

gadabout:

My Eneloops have been rock solid going all the way back to 2006.

Same here gadabout!! Got my first ones in 2006 also, & those are still going strong. Eneloops are the best thing since ‘sliced bread’….
Best investments I have ever made. :+1:

Macka17 · 2018-08-05T14:18:08.000Z

Early Ni-Cads carried memory. After a while whatever you ran them down became starting point for power retention.
and they became less and less a fixed capacity storer. Only used the top section basically.
They had to be drained waay down, regularly to keep them working at full capacity

These Eneloops though. seem to come from a different planet. enjoy them.
I got a 6 pack aaa in my UHF hand held. at least 22 yrs old. Still works when guiding caravan backing.

plasma327 · 2018-08-05T14:56:39.000Z

Is there a difference between the Eneloops pro’s and the standard version?
I bought the pros as when i made the purchase they had no standard versions
so i have nothing to gauge them too. The do work awesome though. I like them very much !

Pete7874 · 2018-08-05T20:54:34.000Z

plasma327:

Is there a difference between the Eneloops pro’s and the standard version?

Pros have higher capacity but shorter cycle life.

DB_Custom · 2018-08-05T21:35:36.000Z

Have used and abused Eneloops for a decade. Take em out of my flash units at a wedding so hot I can’t hold em. Charge 32-40 for events, run the snot out of em, they just keep working. Have some new Pro versions both in Panasonic and Eneloop variety, as well as Imedion cells. All LSD, all abused pretty equally. Even use Imedion LSD AAA in my razor. It lives in the shower, (I think my wife steals it too) even that tiny little cell lasts a long time and just always charges up nice.

Won’t buy a NiCad.

plasma327 · 2018-08-05T21:43:07.000Z

Pete7874:

plasma327:

Is there a difference between the Eneloops pro’s and the standard version?

Pros have higher capacity but shorter cycle life.

OK. Thanks Pete

d_t_a · 2018-08-10T13:10:10.000Z

teacher:

gadabout:

My Eneloops have been rock solid going all the way back to 2006.

Same here gadabout!! Got my first ones in 2006 also, & those are still going strong. Eneloops are the best thing since ‘sliced bread’….
Best investments I have ever made. :+1:

I’ve also had Eneloops from 2006-2008 (AA and AAA), I was able to run a capacity test only last year when I got an analyzing charger.

So far, they have lost not too much capacity (1600-1700mAh for the 2000mAh Eneloop AA) — I haven’t used those batteries that regularly until about last year. And there were times when I just kept them in storage without using them for as long as a year or more.

However, their resistances are very high now (>1000mOhms on the SkyRC MC3000). And when testing the Eneloop AAA on say the BLF A01 copper flashlight (Nichia 219B), the High brightness mode isn’t that different from Medium brightness mode, indicating it doesn’t work with higher-drain devices anymore. But low-drain devices should still work fine.

gerasalex · 2018-08-10T13:17:31.000Z

NiMH-batteries how it is better to store them if they lie without operation? Completely charged or discharged?

Boaz · 2018-08-10T15:03:30.000Z

Doesn't matter .. Nimh has only a small odd tendancy to need re awakened . They nap and need to stretch a bit when they first wake up so the capacity will increase slightly during the first few charges .

Seems like the point of low self discharge batteries is to charge them fully and have up to 75-85 percent of the original charge up to 5 years later ...Where as a non LSD nimh battery will generally be dead in a month or so.

Phlogiston · 2018-08-11T00:52:54.000Z

The thing that kills Eneloops is reverse charging them in multi-cell devices (single-cell devices are safe).

When you have more than one cell in series in a device, one of them will always be ever so slightly weaker than the others. If you run them down to the dregs, that weaker cell will be driven into a reverse charge (it will have a negative voltage!) by the other, stronger cells. That will damage the cell permanently; it may even emit gas.

When your flashlight starts to dim, or your device starts to lose power, charge the cells as soon as you can. Avoid running them right down unless you really have to.