Need info on rechargable batteries

G

gadgetman

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Feb 27, 2000
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I'm looking for info to compare NiMH vs. Li-Ion vs. rechargable alkaline. I'm pretty familiar with NiMH and Li-Ion characteristics but not rechargable alkalines. Specifically, I'd like a AA battery that puts out 1.5V (unlike a NiCad's 1.2V) for a Nikon Coolpix 990 digital camera. I'm more interested in finding a source of AA-sized Li-Ion batteries since they are lighter for the same configuration.

TIA

gm
 
Never mind; I found what I was looking for on the 'net.

No AA or standard sized Li Ion b/c of liability issues with the chargers not regulating the current sufficiently to prevent explosions.

NiMH and NiCd found in different capacities from 450mAh to 1100 mAh. NiMH preferred for the increased capacity and the environmentally safe disposal. Memory effects reduced (not really an issue) in NiMH, although proper charging/dicharging will prevent memory effects in NiCd. NiCd will lose 1%/day on the shelf, NiMH will lose more (up to 10% from some sources, but more likely 3-5%/day). Can be recharged 300-500 times (or more if good charger and a good set of cells is used).

Rechargable alkalines not really that good. similar to regular alkalines in discharge charcteristics; good for low current devices but not high current ones like digital cameras. 1.5V, and close to the same capacity as regular alkalines. Long shelf life compared to NiCD/NiMH. Can only be recharged up to 12-24 times, losing capacity with each recharge.

Pretty good info on this site:
http://members.home.com/andybaird/batteries.html
 
Thanks Brock.

Those 1600 mAh are cool. I'm going to get some. Do you use NiMH's in a PDA? I'd like to try in my Visor but am worried about the voltage (is a PDA a low-current device?).

Also, I read on one fo the sites that the higher capacity NiMH batteries have more internal resistance than the lower (<1200) capacity ones. That would make a difference in a high draw device like a digital camera.

I would probably end up buying the highest capacity available anyway.

gm
 
The Sanyo batteries are a viable option. You may be able to get nearly the same thing cheaper at Radio Shack. Their cat# 23-525 NiMH battery is rated at 1500 mAh (may be higher; they keep raising the rating as the battery technology gets better; this same battery was 1300 mAh a couple of years ago).

While it is true that NiMH batteries have a slower discharge under load rate than NiCds, a higher self discharge rate and a lower maximum charge rate as well, these properties do not cause real world problems.

I use four of these RS batteries in my Casio QV-3000EX digital camera. Have taken up to fifty pics with plenty of charge left. The flash recharges quickly. It is hard to imagine a higher drain item than a digicam, with a powered telephoto lens, powering the flash capacitor repeatedly and running the hard drive.

I have a charger which has a switch for two different charge rates, a lower charge current for NiMH batteries. However, this is not really necessary, since the maximum charge rate of the charger (set to the higher NiCd rate) is still below the maximum charge rate of the NiMH batteries. Thus, it is only a 'feel good' switch. The higher self discharge rate is not a problem. My digicam batteries stay good for a month easily, as do my cell phone batteries.


Certainly a PDA draws nearly no current in comparison. My Palm III runs for months on two AAA alk cells.

Hope this helps, Walt
 
Gadgetman; while rereading your original question, it occured to me that you may not be aware of battery performance, as you were concerned about the lower starting voltage of NiCds vs. alkalines.

The fact of the matter is that NiCd batteries will actually deliver a higher AVERAGE voltage than will alkaline cells. This is because the alkaline cells' voltage drops linearly with use, while a NiCd cell stays at about its' starting voltage until nearly discharged. This is why you get plenty of warning that alkaline cells are dying, as the flashlight gets dim. This is in contrast to one powered by NiCds, which will be bright up until a minute or so before the light dies.

So, don't fret using rechargeables in electronic equipment. They work just fine; I have yet to see an item which wouldn't perform just fine with rechargeables.

Walt
 
The only thing that is effected by the lower voltage of NiMH is LED lights
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For instance if you have a LED light and it wants 4.6 volts and you use 3 alkaline cells you will have that, if you use 3 NiMH you will have 3.9 In the LED world that is a big differnce in brightness.

However as Walt mentioned under most loads NiCd and NiMH will supply a the same voltage than you would get from new alakline cells for almost all their charge.

Brock - http://www.uwgb.edu/nevermab/flash.htm
 
Just as a point of information, I have purchased several AA sized NiMH rechargeable batteries, charger and button style lithium batteries from:

http://www.aspencer1.com/

with excellent results.

The "Supreme Power" NiMH batteries have been incredible in my Olympus D-360L Digicam.

I have had the same batteries in the camera for over a month, have taken well over a hundred pix, and it's still reading as fully charged! (These are the 1500ma rated batteries.)

I don't use the LCD display on the camera much which saves a lot of power, but even so, that's pretty impressive performance.

Cost for 8 of the rechargeables, a charger and 25 button batteries (#2016) was about $40 shipped. It took a couple weeks as they're in Canada but worth the wait.

I have no connection with them whatever other than this one order I placed back in October. They do a lot of business on ebay with good ratings, and are also a "verified" vendor on PayPal.

Hope this info helps.

Blues

------------------
Live Free or Die

Blues' Knife Pix
 
Thanks for all the replies.

Walt, I'm familiar with NiCd/NiMH voltage characteristics; I had sorta forgotten my RC car NiCd knowledge from 15 years ago. I don't know why I had thought that alkalines' voltage was stable throughout batery life when my VDX's voltage display tells me right there!. My bad
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.

I get about a month's use out of a set of batteries in my VDX, but I use AvantGo just about every day. I also found that Mapopolis 2.0 really sucks juice! I start getting low batt warnings (alkaline AAA) at close to 2V, so the rechargables ~2.4V average should work fine. (I use Hackmaster/BatteryHack)

My interest in LiIon was because I'm a weight weenie...comes from mountain and especially road biking. Also, my Sony Mavica FD-88 uses a LiIon battery, whose performance is pretty impressive because the Mavicas don't use a viewfinder; you have to use the LCD display to frame your shots. BTW, It's a decent camera for the 8X optical zoom, mpeg capability, and the point and shoot characteristics, but I'm looking for more resolution and a slightly smaller size (Nikon Coolpix 990 or Olympus C-3030Z) whcih is why I'm interested in AA-sized batteries.

Unfortunately, I'll have to postpone my digicam purchase a little while since I just bought another snowboard.
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gm
 
When I use alkaline batteries in my Oly 460 digicam, I barely fill a 8meg card and the batteries crap out. They are also very warm when I take them out of the camera. When I use NiMH batteries I can fill my 8meg and 16meg cards with plenty of juice left. I use the LCD display all the time and use the flash and zoom regularly. For some reason my camera just plain eats alkalines (Duracell or Energizer).
 
jgeesen; what a peculiar situation! Perhaps your habit of warming the room by turning up the brightness on the LCD when you have alkaline batteries in the camera could explain it.
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I really have no idea at all as to why alks would behave in such a manner, although it is certain that they are under high drain if they get warm during discharge.

Walt
 
I use the Energizer Accu rechargeables(The hi-energy NMH 1200mah)in my nikon 990, they seem to last quite awhile.
Ray
 
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