They Normally state thier mAh on the battery but if not, it is stated on the package you buy them in.Abray said:wow, I never knew batteries were rated in mah!!! Do batteries generally say on them their rating? or do you have to find a data sheet for that type of battery?
Isn't it the other way around... take the capacity divided by the mA...right? mA per hour/mA the mA cancel out leaving you hours...pseudolobster said:again, it will depend on the current you're running the diode at, and the capacity of the specific batteries you want to use.
it sounds like it may be a good idea for you to do a bit more reading before you jump into this.
current is measured in amps or milliamps, batteries are rated in milliamp-hours. for example if you are drawing 100ma, and your batteries are 100mah, your batteries will last 1 hour.
bluray diodes are usually run anywhere between 10mA and 200mA, it depends on the diode... tack 10% on to that, which is what the driver draws, and you have a grand total in mA, divide this by the capacity of your batteries, in mAh, and you will have runtime in hours.
of course, these numbers are theoretical and realworld results will be different, you won't know for sure till you hook your multimeter up to the actual functioning circuit and until you know the exact capacity of your batteries.. but yeah, it'll last a while.
do some more reading though... this is all stuff you can learn by reading this forum.