who long do batteries work at full power

[ben74]

i have a nova x75 laser i put fresh batteries in and i works great for 5 mins then i cant light a match or smoke black plastic is there sum thing wrong and is there a small laser that uses AA instead of AAA and would it last longer

 

[Razako]

Try using lithium AAAs for longer batter life.

 

[desslok]

You can usually find "High Capacity" type batteries as well in most sizes. Look on one of the online stores. Basically look at the maH rating on your batteries, and then look for something with a higher rating. For example you may have a 1500 maH, but can find a 2650 maH battery online.

Also, alkaline batteries usually have higher initial voltage, but decrease in voltage pretty quickly, while other types and rechargables tend to have less voltage, but they stay at that voltage pretty steadily.

 

[ben74]

would 1000mah AAA work fine for about 20mins

 

[Gazoo]

would 1000mah AAA work fine for about 20mins

Suggest you get sanyo eneloops. I run them in mine and they last quite awhile.

http://batterybob.com/product.asp?intProdID=559040

Any questions you might have about batteries have been answered in the following thread. It is quite a read but worth your time:

http://www.laserpointerforums.com/forums/YaBB.pl?num=1196628709

 

[desslok]

would 1000mah AAA work fine for about 20mins

mah stands for milliamp hour, similar to how the electric company charges you for electricity, how much current over an hour. If you know the operating current of the device it's a simple math problem at a given temperature. For example if your device operates at 1000 mA, then a 1000mAh battery would last 1 hour. If it operates at 200ma, then 5 hours, etc.

 

[ben74]

so how much maH in a standard alkaline batteries

 

[Gazoo]

An alkaline AAA battery battery has a rating of ~1250mah. However a high capacity AAA nimh battery will blow an alkaline away in run time because alkaline batteries can not hold up to higher currents. Look at page 6 of the Energizer data sheet and you will see a graph that compares the battery chemistries.

http://data.energizer.com/PDFs/alkaline_appman.pdf

Also keep in mind alkalines sag quickly, where as nimh batteries don't.

 

[SteelRain]

For lasers, i recommend using NiMh rechargeable batteries. You can charge them hundreds of times and they last long if you get a good few. Alkalines have a higher voltage but they have trouble keeping that voltage and will lose it pretty quickly. Also, alks can have a pretty high mAh rating, but in high draining unit, it will lose more energy

For instance:
In a remote-you may get 2000 mAh out of an alk
In a laser or camera-you may get 600

NiMhs hold their charge over a while, but run at 1.2 volts.

 

[desslok]

so how much maH in a standard  alkaline batteries

You also have to look at discharge rates, not just mah. For example, a nimh rechargable will stay at 1.2 volts most of it's charge, while an alkaline will start at ~1.5 but quickly and steadily lose voltage, until it's too low. You can see it really good with an incandescent light hooked up to each. The nimh will stay bright until it dies, the alkaline will gradually get dimmer until it's barely lit. Here is an example of a graph:

http://site.greenbatteries.com/documents/alkaline-vs-nimh.jpg