Eneloop Voltage Sag

They always work fine in flashlights and radios, but have trouble in my camera. With lithium AA's and also a pair of old Duracells NiMH's camera start-up with lens extension is fine. But, with Eneloops the lens will often just extend part-way. My theory is that the voltage is sagging to the point that the camera's not getting enough to finish the start-up.

Does that make any sense? Anyone else noticed such a thing?

Geoff

That's not normally expected from Eneloops. Quite the opposite in fact.

Worth making sure first of all that they are making good contact with the battery terminals in the camera.

What about the age and history of the Eneloops? How do you charge them?

Usually I would suspect from these symptoms that batteries have been charged on a slow timed charger for many cycles and have developed a high internal resistance. The typical cure for that would be a refresh cycle or two with a full discharge and faster charge rate.

How about the self-discharge performance? Is that still good?

One thing I notice with my digital camera.. I had a couple times of using Eneloops and my camera didn't perform very good with them, but the camera worked great with the crappy energizer nimh's.

I use an energizer fast charger with the cheap energizer cells, it takes about 15 minutes to charge them up... and they come out around 1.45 volts off the charger!

My camera seems to run better when I use a better charger on the eneloops (Maha MH-C9000) when compared to the stock charger that comes with them.

I've noticed times when eneloops that have sat for a short while (not that long, maybe 3-4 weeks) and were used in my digicam ... sometimes i'll get the dreaded "change batteries" even though I know theres a ton of juice left.

I then charge with my LaCrosse bc900 and find out that the voltage is alright and when charged up the batts only took 8-900 mAh. What's up with that?

Do these batts need a couple of full charge/discharge cycles to get the internal chemistry going?

here, its the driver of my camera (Lumix something, 2 AA batts).
Says the cells are empty --> cells out and into charger --> discharge --> still some 1000-1500 mAh inside.
Driver in cam just stops working too early.

... happens with all the "precharged" AAs I have, not only with the Eneloops.

That is strange. I have quite an opposite experience. In my canon camera eneloops last as long as 2500mAh nimhs...

This is strange. The experience of most people is that Eneloops have a higher voltage and better performance in cameras than other kinds of NiMH cell. I have seen this myself and UnknownVT has reported the same thing after extensive testing with a very voltage sensitive camera.

For those people (Flying Turtle, divine, yellow) reporting problems, what charger do you use and how are you charging them? I'm wondering if the type of charger may have an influence.

Hello Bill n opus,

Very interesting observation with your charger...

In 30 days, the Eneloop cells will loose around 140 mAh of capacity. You mentioned that your charger puts back around 850 mAh when you charge them.

Allowing for inefficiencies involved at slow charging rates, I think you should only see around 200 mAh going back in.

On the surface, it would appear that your charger is missing the charge termination signal and is overcharging your cells. NiMh cells are sensitive to overcharging, and LSD cells are even more sensitive than regular NiMh cells.

You may want to consider raising your charge rate to a point where the end of charge signal is a little stronger.

Tom

Hello Geoff,

If you would like to run a test, try this.

Turn your camera on and note the performance. Then shut the camera off and turn it back on again, once again noting the performance.

Sometimes these cells will develop high internal resistance after sitting for awhile, but this quickly goes away after first usage.

As Mr Happy stated, this is most unusual. It is possible that you are having issues with a cell, or that your charger is not doing a good job. We need to narrow the options down and go from there.

Tom

"Sometimes these cells will develop high internal resistance after sitting for awhile, but this quickly goes away after first usage."

Click to expand...

So if I am a very casual user, meaning I charge my batteries put them in my digital camera, and use them once every 2 or 3 months, will these cells develop high resistance? I do not think this would be beneficial for a casual user like me.

As a matter of fact I am charging them on a BC700 at 500 mA, is this a good setting for this charger or should I be using 700 mA? Per Sanyo it is better to charge them at a low rate.

Thanks.

I think cameras must vary quite a lot between makes and models.

I leave Eneloops in my camera (a Canon A620) for months at a time between uses and it always starts up and takes pictures without trouble. I have never seen a low battery warning on it until the batteries really are nearly empty.

I also leave Eneloops for months in other things like flashlights, cordless screwdriver and soldering iron and they also work fine with no apparent loss of power.

Mostly I charge my Eneloops at the default 1000 mA in my C9000, but I sometimes charge at 1600 mA if I am in a hurry. As long as the cells do not get excessively hot at the end of charging then higher charge rates are safe and even preferable.

It seems alot of cameras have, quite frankly, utterly crap electronics. I've seen some HP cameras that complain about low battery even with 2 fresh lithium AA.

Thanks for all the tips, folks. It's quite possible the batteries are not getting proper charging. I have a Duracell charger that puts out 400 ma per channel. Maybe it's not completing the charge, even though it says it's done. Also, the batteries have been charged fairly often and are about two years old. I might have to break down and upgrade.

The camera is a cheap Samsung that never misses a beat with lithiums, so I think it really likes that bit of extra voltage.

Geoff

easily overlooked are battery contacts with contamination that'll create
high resistance and make the camera think the cells are low.
1.) don't be eating french frys or doing other oily tasks before you take the cells out of the charger to place into the camera.
2.) cotton swab battery and camera contacts with a cleaner *iso alcohol.
3.) voltage test the batteries under a load -10 ohms?- to see if the voltage
goes below 1.1volts. That would mean the cell is bad or uncharged.

I've experienced this problem with Eneloops in two different Canon A5xx series Powershots (2AA powered cameras) and also on a Samsung 2AA-powered model. When I use L91 lithiums in one of the Canons it works fine; I haven't tried with the other cameras. I've speculated that the dc-dc converters in these cameras just barely work at 2.2 volts or whatever a loaded Eneloop supplies, and that it's similar circuitry to the 3.6v lithium powered models (I hate proprietary lithium rechargeables and only buy AA-powered cameras). I've been thinking of looking for an A6xx Powershot (all discontinued) just to escape from this low voltage situation. The A6xx's are a bit larger and use four AA's, so more voltage is available, plus they have a few other nice features like a flip-out screen. Mr Happy's A620 is one of that series.