hi, i want to know if a battery runs longer depending on its mah (i believe that is the battery's current?). i am running a 6 volt 20watt mr11 halogen projector lamp as a bike light. i need more battery life because even over driving the light using 8 AA 1800mah batteries is not enough. i was wondering if batteries that contain a higher mah rating would give it more battery life. any help is much appreciated. thx!
battery run times
- Thread starter halocon
- Start date
EvilLithiumMan
Enlightened
'mah' -(milliampere hour) is the ability of the cell to deliver current over time. Your cells are rated to deliver 180ma over a ten hour period. If they were perfect, they would also deliver 1800ma for one hour or even 180 amps for 1/100 of an hour. (But we know they aren't perfect).
Your load is a nominal 20W/6V = 3.33A. Theorectically, you should be getting 1800/3333 hours of run time. (About 32 1/2 minutes). But at that heavy of a drain rate, I'm guessing your cells only last for 15 minutes.
As you surmised, you want more capacity (mah). Nimh C-cells have about 4500mah capacity. D-cells typically have 9000mah capacity. Thomas Distributing carries MAHA Nimh D-cells with a 11AH rating. $32 for a pair, I believe.
Your load is a nominal 20W/6V = 3.33A. Theorectically, you should be getting 1800/3333 hours of run time. (About 32 1/2 minutes). But at that heavy of a drain rate, I'm guessing your cells only last for 15 minutes.
As you surmised, you want more capacity (mah). Nimh C-cells have about 4500mah capacity. D-cells typically have 9000mah capacity. Thomas Distributing carries MAHA Nimh D-cells with a 11AH rating. $32 for a pair, I believe.
