Alkaline vs NiMH (Nickel Metal Hydride)Batteries.
Posted by Jerry_NJ (My Page) on Sun, Dec 26, 04 at 17:36
Testing a Digital Camera Christmas present: The initial results were so disappointing I was thinking I'd send the new digital caamera back because of poor battery life. The camera has 2 AA batteries (I note my only other experience is with the Konica Minolta Z10 which has 4 AA batteries).
Here's what happened. I first installed the two Panasonic Alkaline batteries supplied with the camera (good name, assume they are at least average). The camera came with only 16 Mbytes, so only about 18 pictures. Well, even though I had used some battery capacity learning and setting the date, I was shocked when the battery warning came on after only about 8 pictures. So, I figure, old batteries, and I place with two new Alkaline batteries, to have a "A" "A" test, in (these are the bargain priced Toshiba from BJs) and AGAIN, battery warning before I could even complete the next 10 pictures. So, I figure, either just a bad design or defective, it'll go back to TigerDirect. But, just to see, I put in two NiMH rechargeables I had on my desk, they hadn't been charged in some time, so there were not freshly charged. I then played with the camera, looking at what was in the memory and shooting flash pictures in the basement. The batteries held up. I think so replaced them with fresh MiMH batteries to start a fresh test. We took the camera for a walk, shot all 18 exposures, batteries held up and the indicator "said" partly used. I then downloaded to a computer, went out and shot another 18, and downloaded to a computer. The battery indicator still says partly used, no warnings yet. This has led me to decide to keep the camera, it has a lot of features for the price I paid.
Well, why the long battery story? I just figured others could gain from the results of my experiment. It seems to say that the NiMH, rated at about 2000 MAH, about the same as an average Alkaline, hold up at least three to four times (I'm still counting) longer than the Alkaline I've tested. What's your experience? Could it be that the type of load presented by the digital camera, high current for short periods, kill alkaline batteries in short order, but are "business as usual" for NiMH? I believe the NiMH have a much lower internal impedance, so less internal heating when delivering high current.
Follow-Up Postings: RE: Alkaline vs NiMH Batteries.
Posted by: Grandms (My Page) on Sun, Dec 26, 04 at 21:55
Jerry, I have the Konica/Minolta Z1 camera you mentioned, and the same thing is true if one tries to use alkaline batteries. I don't know the real reason, but there is no comparison with the life of the NiMH batteries, which seem to go on and on and on and . . .
Follow-Up Postings: RE: Alkaline vs NiMH Batteries.
Posted by: PoohBear2767 (poohbear2767@despammed.com) on Sun, Dec 26, 04 at 21:57
Here are some thoughts that come to mind. Alkaline batteries create energy chemically. NiMH batteries store energy like a sponge.
What is the energy density of each type. And as you said, the internal resistance is lower for the NiMH.
Pooh Bear
Follow-Up Postings: RE: Alkaline vs NiMH Batteries.
Posted by: fruitjarFla (My Page) on Mon, Dec 27, 04 at 10:01
NiMH rechargeables are now up to 2500 MAha capacity. The cost obviously is more at the outset but the benefit over the life of the batteries far exceeds akaline. Any variety is available from a company I purchased from 3 times. www.nimhbattery.com
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Batteries
A usage guide
Battery chemistry:- A number of battery chemistries are available. The following comparison chart comes from the January, 2002 issue of Embedded Systems Programming:
|
Chemistry |
Vnominal (V) |
Max. load current (C) |
Energy by weight (Wh / Kg) |
Energy by volume (Wh / L) |
Operating Temp. (deg. C) |
Re-charge-able? |
Life cycle (recharges) |
Shelf life / self discharge |
|---|---|---|---|---|---|---|---|---|
|
Alkaline |
1.5 |
|
150 |
375 |
-20 to 55 |
No |
|
5 yrs to 80% |
|
NiCd |
1.25 |
>2 |
45 - 80 |
125 |
-40 to 60 |
Yes |
1500 |
20% / month |
|
NiMH |
1.25 |
0.5 - 1 |
60 - 120 |
180 |
-20 to 60 |
Yes |
500 |
30% / month |
|
Lithium Ion |
3.6 |
1 |
100 |
270 - 325 |
-20 to 60 |
Yes |
50 - 100 |
10% / month |
|
Lithium polymer |
3.7 |
0.2 |
120 - 160 |
230 - 270 |
-20 to 60 |
Yes |
500 |
10+ years |
|
Lead acid |
2 |
0.2 |
30 |
80 |
-20 to 60 |
Yes |
200 - 500 |
5% / month |
|
Zinc air |
1.4 |
|
300 |
1150 |
-20 to 60 |
No |
|
3-12 wks to 50% |
|
Silver Oxide |
1.55 |
|
130 |
500 |
-20 to 60 |
No |
|
2 yrs to 84% |
Note that here load current is expressed in units of C (which is just the Amp-Hour rating of the battery divided by 1 Hour).
Battery availability:- A number of types of small batteries are available to us:
"Button" cells -- 1.25V each; alkaline or NiCd; these are the smallest, but also have a fairly low energy storage capacity
AAA -- available in alkaline, NiCad, NiMh
AA -- available in alkaline, NiCad, NiMh
"9V" -- available in alkaline, NiCad, NiMh; you'll need to use a voltage regulator to get the output voltage down to something CMOS can stomach (usually, 5V).
9V battery cells -- alkaline only. 9V alkaline batteries are made up of 6 clustered cells in a can. You can pull open this can (carefully) with pliers to pull out the small cells (which are a bit smaller than AAA batteries). Since these aren't rechargeable, I don't use them much.
Cordless phone batteries -- these are easily salvaged (and in high availability, if you go through cordless phones as often as I do) NiCad batteries -- most output 3.6V, which is just right for most BEAMbots.
To put things in perspective, I have a page comparing charge capacity, size, and weight for basic cells (AAA, AA, 9V) of differing chemistries here(http://library.solarbotics.net/pieces/parts_elect_pass_batcomp.html). From this page a paragraph is given below;
From these plots, we can conclude a few things with respect to battery selection and energy storage density:
For NiMh batteries, AAA batteries are king
For NiCd batteries, AA batteries are a better choice (being about 30% better than AAAs)
For any battery chemistry, "9V" batteries are only a good choice when battery (physical) size is a more important consideration than storage density or battery capacity (i.e., battery life).
Note:- Contents are not in its original shape but edited/arranged for personal use/convenience.
By:
Muhammad Shafiq