? on rechargable flashlight batteries

[dudevato]

   This concerns the 'info' found on the labels of flashlight batteries.  I see on the side of my AA batteries it's stated "1.2 volts & 2650 mAh"  Well, I see the  numbers on the much larger D size batteries say "1.2 volts & 2500mAh.  I'm thinking either the AA's (NiMH) are large capacity or the D's (nickel metal hydride) are small. My mind does not let me accept they both have the same 'juice' in them.  Am I missing something? I'd love to get any thoughts or input from anyone.

   What prompted this post is that my digital camera seems to drain its 2 double A batteries Very fast.  Granted I use the re-chargeable kind (and the instructions say not to)  I'll take 4 or 5 pics, then shut off the camera and 2 days later the batteries will not turn on the camera.  I thought I'd wire up a couple of D size batteries, so I made up a little 'pack' that is screwed onto the bottom of the camera.  It's made from a couple of plastic D size 'holders' from Radio Shack and wired into the camera via a couple of hollow wooden dowels that have roofing nails fastened to the ends, to make contact with the camera's tabs. I turned the camera on and nothing smoked  The D's are on the charger now.  I'd love to read your thoughts on my battery delemma.

   I'd hate to think I need to Buy batteries each time I want to take some pics.

   Thankyou for your time and knowledge.

[ghurd]

C and D cells tend to be mostly rolled up cardboard.

The "battery in the battery" is about like a AA.

Much higher capacity Ds are available, but it won't be something available locally for most people.

I recall seeing Ds in 9000mah and 14000mah.  They are not cheap.

Hosfelt has 6000mah Ds (nimh) for $8.39 each.  (Just to supply some type of referance point.)

G-

[Tritium]

Some cameras, particularly Olympus have a LVD (low voltage drop out) circuit that will not allow reliable operation with some battery types since they are set up for standard alkaline battery chemistry's and the associated higher voltage of alkaline cells. I have several Olympus cameras and they will work with some brands of NiMh and not with others. I do have AA size cells that are 2500mah.

Thurmond  

[zeusmorg]

 The voltages on alkaline batteries are rated at 1.5 v. A new one usually tests out at 1.75 v. The problem with using niMh to replace them is they are rated at 1.2 v and usually will charge up only to 1.45 v. In some electronic devices they will not work due to the voltage differences.

 And yes most D cells are just filler to make them fit in a d cell application.

 So you're either stuck with replacing with alkalines or building a rechargeable battery pack and dropping the voltage to match your specific application.

[Slingshot]

You didn't mention the brand and model of your camera, so it's hard to say if it is overly sensitive to battery voltage.  If the manual says not to use rechargeables, then probably it has a low drop-out voltage.  Alkalines are nominally 1.5 volts per cell.  It is likely your camera is shutting down even though the batteries still have plenty of charge.

When your camera says the rechargeable batteries are too low, take them out and measure with a voltmeter.  You may find that they are fine.

[dudevato]

Thankyou to all that have commented on my ?  You've all just easily doubled my knowledge of the subject.  dudevato

[Norm]

I have a camera that I use 2 AA rechargable

batteries NiCad batteries when charged to 1.35

volt each will run the camera for about 10 pics

including....the secret here is to have 4 or 5

sets fully charged with a handy litte home made

dispenser pak.

An alkaline battery that reads 1.2 volts isn't

the same as a NiCad that reads the same voltage

....under load the voltage on the alkaline cell

will drop and the camera will fail to operate..

(took awhile for me to figure that one out)

[hamitduk]

Lenmar makes 1.5 VDC Charge-ables, reasenable price, $14c for the charger and 4AA's.  I get them at fry's Elec.

Hami

[scottsAI]

Dudevato,

Subject I have studied. Designed a AA battery cycle tester a while back.

My camera says alkaline only.

I use NiMH with good results. (better life than expensive alkaline)

I bough a batch of cheap NiMH (2500mah), first use were amazing. Second less amazing, by 4-5 uses, on par with life of alkaline, continued to go down hill from there. Stopped using by 10 cycles. The good news, the batteries cost less than a good alkaline, not too disappointed.

A good NiMH battery cost 3-4 times as much, may last longer. Older (energizer) 2000mah worked in the camera on par with alkaline, had way more than 10 cycles.

Improper charging can kill even a good NiMH.

Make sure you have a good charger.

Over charging will dramatically reduce the life of a NiMH battery.

If the charger makes the battery hot for a long time stop using it. Last half hour is the longest the battery should be hot. Longer starts destroying the battery.(search Google on it)

Be careful on your interpretation of HOT. Few deg over room temperature is normal for charging. If difficult to hold then too HOT. My intelligent charger (PowerEX) will sometimes make the battery very hot. Other times barely warn. No rime or reason. Stand by hold, usually battery is room temperature, other times rather warm.

Recently bought some Juice AA 2000mah batteries, use in a flashlight that gets left on frequently. Works fine in this application, got them for 41 cents each. Not tested in anything else.

Have fun,

Scott.

[RedLance]

I have an Olympus c730 camera.  I have been using Rayovac "Hybrid" nimh batteries in it, with good results.  Normal nimh batteries have a very high self discharge rate.  The Hybrids are supposed to retain 80% of their charge for up to a year.  I paid about $10 for a 4 pack, and they are 2000mha.  They run the camera for a couple hundred pictures, I would guess.  I haven't been able to find any Hybrids lately though.  I think all the new Rayovac nimh are the Hybrids, just not labeled as such anymore.  If the package does not state that the batteries must be charged before use, then they should be hybrids.

I have yet to obtain a good charger for nimh.

[Airstream]

The packaging 'keyword' for the new technology MiMH rechargables is "pre-charged" - if you see that on the label its the new low self-discharge type. Its great to have them for cameras and flashlights

I bought four Kodak brand 2100mAh's for $12 and last night a four-pack of Duracells with a 6-hour charger (labeled 1.4V/cell) for $16...

[ghurd]

Our luck with Olympus was horrid. (start rant?)

Couple or 4 cameras, maybe 30 outdoor non-flashed pics with name brand alkalines, over a few hour span.

My sister got my Dad another Olympus in June, because that's what she does.  84 photos used up 5 sets of alkaline batteries. (he writes that stuff down)

Had a new high-end Olympus work for about 40 shots.  Sent it back because too long to return it to the retailer.  They had it 6 months.  Didn't work when they sent it back.  Sent it back, and the warrenty was up (go figure).  Paid to have it fixed.  After several more months, again, it didn't work when they returned it.

This taking over a year, we had already purchased a replacement camera.

Just as well.  I can't afford $20 per photo.

Cheap Toshiba with a real zoom.  Works great.  Very abused. Broke the zoom button. ~100 shots per pair of 2000mah AAs.  Still works without zoom.

The Kodac Z740 gets ~100 per pair of 2000mah nimh AAs, with a real 10X zoom.

Zooms eat batteries.  Wife likes using the zoom.

Guessing 20,000 shots, even some videos.  And it still works!

G-

[Airstream]

Life of batteries sure depends on what you start with... The December 08 Consumers Reports had a battery test - Energizer Max came in LAST out of 13 alkaline brand tests with $1.19 cost for 50 digital pictures! Since energizer is pushing their lithium and titanium brands I guess they cheapened up their base alkaline. That Max battery is everywhere too, I guess it has a high margin for the retailers.

Olympus isn't the only brand with problems, a few years back the Fuji line of digital cameras had problems with the shielding materials they used, the entire plastic housing including battery cover was a conductive plastic and people found one AA battery out of four was rapidly self discharging simply by being in camera!

[ghurd]

"max" means take the most money they can get from the buyer.

It get me some items can claim 20% better but charge %200 more, yet people buy them.

"New and Improved"?

I love Enegerizer Industrials (not available for retail markets), but they are not much better than Family Dollar brand AAs.  My cost is close.  I tend to use Family Dollar for the bang:buck ratio.

Smoke Alarms, etc, would get a name brand alkaline.

My personal Head to Head alkaline tests, a few years ago, with low drain items (LEDs) showed very little difference.  Mostly battery weight tells the winner.  Cheap crap batteries are easy to feel they don't 'weigh up'.

About the same for nicd. Heavy is better.

Nimh too.

But don't compare nicd and nimh weights.  They are not the same animal.

G-

[RedLance]

Hmmm...interesting.  My Olympus was just great.  I got it refurbished.  Has the 10x optical zoom.  Like I said, I got a couple hundred pics per charge, mixed indoor/outdoor.  Then I dropped it and the lens popped out.  Still works, but I think the pictures are all blurry now...

I actually like Radio Shack alkalines the best for non rechargeables.  I can't remember what the device was, but I did a comparison years ago, and found they lasted much longer.