The secrets of eneloop batteries

On a sunny day (Sun, 23 Sep 2012 18:25:44 -0400) it happened "Michael A. Terrell" wrote in :

over them :-)

Possible, but this guy ships a lot, and very fast, he only does batteries, so.. and this is his main product.

On a sunny day (Sun, 23 Sep 2012 18:25:08 -0400) it happened "Michael A. Terrell" wrote in :

Oh I did, but it must have escaped your undivided attention tha that article is from September 2012, refecting on some scribblings from 1012??? that as of April 1 2012 the name Sanyo is no more. It clearly is here, so that article is worth as much as the webpage. I am not saying Panasonic does not have plans, just that article's analysis is crap.

Reality, my batteries, their OWN website, proves you wrong on April one date.

On a sunny day (Sun, 23 Sep 2012 17:31:52 -0400) it happened " snipped-for-privacy@att.bizzzzzzzzzzzz" wrote in :

Oh my god, did she have a head ache again??

On a sunny day (Sun, 23 Sep 2012 18:27:19 -0400) it happened "Michael A. Terrell" wrote in :

No, that was the US. :-)

They're good. I've had equal experiences with RayOVac's "Hybrids". Unfortunately it's a moving target--they keep changing the name. I think they're calling 'em "Precharged" now, or "Platinum" or something.

I *really* like the PowerGenix NiZn cells I have. They're fragile, die if you let 'em run too low (be sure you buy them charged, or they're ruined), but the higher terminal voltage works a lot better in many devices. I don't expect nearly the advertised number of charge cycles, but even 10 cycles more than pays for them.

-- Cheers, James Arthur

On a sunny day (Mon, 24 Sep 2012 07:18:23 -0700 (PDT)) it happened snipped-for-privacy@yahoo.com wrote in :

Hey, thank you, did not know about that. Will probably get some, more capacity, more voltage, and even cheaper here than NiMH The charger I will program myself :-)

Do you have to change low charge cutoff voltage from 1.0 or 1.1 to 1.3 V?

On a sunny day (Mon, 24 Sep 2012 07:18:23 -0700 (PDT)) it happened snipped-for-privacy@yahoo.com wrote in :

Hey, thank you, did not know about that. Will probably get some, more capacity, more voltage, and even cheaper here than NiMH The charger I will program myself :-)

Do you have to change low charge cutoff voltage from 1.0 or 1.1 to 1.3 V?

On a sunny day (Mon, 24 Sep 2012 07:18:23 -0700 (PDT)) it happened snipped-for-privacy@yahoo.com wrote in :

Upon reading the datasheeets: self discharge is to 60% in 28 days! Capacity is a lot lower than NiMH too.

Eneloop is better than that in 5 YEARS.

So that is a no-no.

No, you're not qualified.

The ENELOOP chargers have an odd flashing LED scheme to report on charging. You can google to get the decoder ring. But I believe it has a discharge before charge mode. I triggered it once. I suspect there is some poing where Sanyo didn't want to just top off the battery and believed a dischrage before charge would be more appropriate.

When it comes to rechargables, it is best to keep the batteries associated for one device grouped together. That way it is most likely that they will be discharged to the same amount.

Some of my devices have a programmable battery lower voltage limit. Other have a program mode for alkaline or NiMH. It is best to not mix and match those batteries with devices that don't protect the batteries, since the devices with programmable cutoffs have probably treated the batteries better.

I don't have any flashlights that aren't LED anymore. [Even modified the old maglights for LED.] But a flashlight with a filament bulb will most certainly overdischarge a second cell.

I have Enloop batteries. I bought one of the early packs with the charger and liked them so well I bought another, both at Costco. My main problem is keeping track of all the batteries.

They have saved me buying any more disposable cells for the last four years I believe. I guess I still use disposable cells in my clocks and a couple of lights I use on the kayak. I even keep a set of four in my kayak bag in case one of my powered units didn't get charged and I have to swap them out. So far they have only been loaned to other paddlers who's units with disposable cells have run out of juice. Keeping all my units charged is a little work, but I never run out of power on the water.

Rick

On a sunny day (Mon, 24 Sep 2012 14:26:09 -0700) it happened miso wrote in :

Thanks, yes that idea of doing some discharge may really help, tried it last night, Almost like those eneloops get used to low discharge current, need to have a bit of a big one every now and then.

I don't know where ENELOOPS set the minimum voltage, but probably you don't want to go lower than 1V to be on the safe side.

Battery charging algorithms have a lot of black magic. A person in the lab could never test all these charging limits, at least as they relate to battery lifetime, unless they are rapidly discharging the batteries.

I forget who had a patent on battery burping, (discharge periodically while charging). Nobody licensed it because it was dubious at best science. By the time it could be proved to be useful, the chemistry will already have changed. (More patent nonsense IMHO.)

The actual self-discharge is a lot better, by my measurements. The main problem is, like LiIon, the cells die (go hi-z), seemingly if you ever let them go too low.

These guys talk about some of the challenges (posts #1, #20):

f-NiZn-Cells

Post #20 says that zinc just won't ever work in a rechargeable, that charge cycles quickly amplify infinitesimal defects.

The cell is nearly fully discharged at 1.4V, so yes, that gives you fairly little low-battery warning in devices set for alkaline cells.

I like them in devices that don't work well on NiMH voltages. My favorite camera reads "Battery Low" on freshly charged NiMH, and shuts down long not long after. It barely works at all on expensive alkalines, works great on NiZn.

LED flashlights with converters work better on the higher voltage, as it greatly reduces the i^2*r loss in the battery connections & circuit. (It's surprisingly difficult to get 1A @ 1.2V efficiently.) One of my handiest lights uses a single AA, and works tremendously better on 1.7v than 1.3v.

So, there are some limits, but compared to $0.25/ AA alkaline cells (that don't work in the camera), these have provided excellent service for two years so far, at a cost of $2/cell.

-- Cheers, James Arthur

Duracell's NiMH literature says you won't hurt the cells even down to slight reversal. Zero volts is fine.

-- Cheers, James Arthur

0V is fine for any Nickel cell (-.1V, not so much). The problem is in the multi-cell batteries (or, obviously, multiple cells in a device). Guaranteeing that no cell reverse charges leads to rules of thumb like "discharge only down to 1V/cell". Of course, this is dependent on the number of cells in the string.

When were they made? Most of what I see for sale is the new labeling.

I just bought 50 3400 mAH sub C NiCad cells to repair some of my equipment. It's amazing how fast they add up when you use old test equipment. The built in chargers won't support NiMh.

On a sunny day (Tue, 25 Sep 2012 04:27:39 -0700 (PDT)) it happened snipped-for-privacy@yahoo.com wrote in :

Yes, I agree with most, some remarks: The eneloops have a slightly higher voltage too, and that makes my Canon camera a bit more 'ready to shoot'.

The thing that really had me thinking was that I found a site that sells NiZn, and it did not mention mAh, but mWh. At first glance I thought this was a printing error, but then, reading the datasheets, found that is is deliberate. The mAh is MUCH lower for an AA than for a similar recent NiMH, so they mention mWh, as that is, with 1.6 V cell voltage, a bit more (but still lower than a NiMH).

But for the consumer, who looks at capacity, and is used to mAh, and sees mWh, will he / she fall for the high number, or at least not be turned off by the low number (that mAh would have had). So is this fair practice? Very difficult to say, as you COULD reason that NiZn will indeed last longer before dropping to 1.1 or 1.0 V where niMH equipment (I use 1.0 myself) switches off. But then if that kills the battery what good is it? So that is not right in my view, and other reason to not use them. I like the idea of NiZn, simple, but they have some way to go before they become competitive it seems.