Most "efficient" battery size???

S

Squid

Joined
Jun 21, 1999
Messages
358
I know flashlights are a favorite toy amongst us gadgetheads, so I figure I can get some good advice here.

I've always wondered which battery size is the most efficient - AA, AAA,C, D, Lithium?

I know lithiums have the best shelf life, and AA and D seems to be the most versatile (in terms of their popularity in use (radios, flashlights, toys, etc.).

Is there a best battery???

 
Hi Squid! Too many variables in this one as far as I'm concerned. There's your "conventional" flashlights using more incandescant bulbs from straight vacuum to halogen, krypton and xenon filled bulbs. The xenons are very bright, but will take a toll on battery life. These are used with all types of batteries, but the lithiums will have the best power. For a light that lasts a long time, but not as bright, look to the led types. These can last up to 100 hours of continuous use! I see the led types as a tent light camping or around the house if the power goes out, etc. When you are searching in the dark, or in an emergency situation, a bright light is needed, and the xenons with lithiums are great, but won't last but about an hour.

Hank
 
Efficiency is not a word I would use in this discussion. What I think you wish to know is how much energy storage there is in a given battery type and size.

Frankly, I am not sure, although I do believe that alkalines store less energy than do Lithium batteries, and the new titanium batteries fall somewhere inbetween.

Another thing of importance is the rate at which the energy can deliver. Here the Li is the best; it can deliver so much power that they have to put a temperature cut off switch inside the battery.

As far as xenon lamps go, they have an amperage only about 10% higher than a comparable krypton lamp and the krypton lamp is about the same as a standard vacuum PR with regards to amperage and battery life. The big advantage of xenon lamps is their efficiency, which allows them to deliver much more light than either a standard PR or krypton lamp.

You may wish to publish your question on candlepower forums, where it would receive more expert attention: http://www.candlepowerforums.com/cgi-bin/Ultimate.cgi?action=intro&BypassCookie=true

Hope this helps, Walt
 
If you're asking how much power each size holds or wattage I can tell you. Here are a couple of common battery sizes.

Alkaline cells
AAAA 1.5v @ 0.595amp hour or .893wh
AAA 1.5v @ 1.150amp hour or 1.725wh
AA 1.5v @ 2.850amp hour or 4.275wh
C 1.5v @ 8.350amp hour or 12.525wh
D 1.5v @ 18.000amp hour or 27.000wh
Lithium cells
AA L91 1.6v @ 2.900amp hour or 4.350wh
123A 3.2v @ 1.300amp hour or 4.160wh

The advantages of Lithium are the flatness of their output. As an alkaline dies the voltage constantly drops, while Lithium's hold their voltage until just before they die. Also Lithium batteries are not effected as much by cold temperatures. Lithium's also have about 4 times the shelf life of a alkaline battery.

I got the info at the Energizer site, pretty handy and has almost every battery I can think of and the physical size and electrical characteristics
http://data.energizer.com

Brock

[This message has been edited by Brock (edited 11-21-2000).]
 
Peculiar data. The industry usually specifies battery capacity in milli Amp hours. For example, D cell NiCd's (the heavy duty ones from Radio Shack) are 4500mAh. Under this system, I believe that D alkalines are about 10,000mAh.

Walt
 
I went to the Energizer site, and they listed CAPACITY in mAh. Here are the data:
AAA: 1150 mAh
AA: 2850 "
C: 8350 "
D: 18,000 "
EL123AP: 1300 mAh

Walt
 
Hey, Brock; thanks for the site. BTW, while there, I checked out the new titanium cells. They have EXACTLY the same capacity in mAh as alkaline cells. So what is the big deal with them; I thought they had more capacity??

Incidentally, the mAh are figured with a 25mA drain down to 0.8 V. Walt
 
As far as the new Ultra and Titanium lines I think a lot of it is marketing. Like you mentioned they all have the same capacity so??? Maybe they have a better discharge curve more similar to lithium?

Walt, yes I just changed the mA rating in to A ratings, or milliamp hours in to amp hours. I am used to dealing in amps so I switched them. So an AA cell being 1150mA is the same as 1.150A amps. Make since? I also should really add the "H" after each one also. Really the important numbers to me are the wattage of each cell, because that's what you are really getting from the battery.

Brock
 
Brock; you should really put in the 'hour' in Amp hour. Otherwise it doesn't make scientific sense, and is confusing. To those of us who have trouble remembering Ohm's Law. Not to mention whether or not the Supreme Court of Florida has repealed it.
wink.gif


Walt
 
Consider it done (actually it already is)
wink.gif
It is one of those things I take for granted when talking about batteries. Walt, thanks again for pointing out I was being vague.

Brock
 
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