batteries choise for DIY canlight

[attchoum]

hi

i what to do a can light and i read a lot about it.

i thing stay unclear, choise for batteries... if i what to light a 50w halogen light what should i take??

what do you thing about this kind of batteries pack: http://cgi.ebay.ca/12V-3000mAh-NiMH...99305QQcategoryZ51029QQtcZphotoQQcmdZViewItem

any one can explain how to calculet what i need?

thx for your help
etienne

 

[jonnythan]

3000 mAh won't get you too far with a 50w halogen... maybe 45 minutes of burn time.

(to get an approximate burn time, take the wattage divided by the voltage to get the amperage.. in this case about 4.2 amps, and divide the Ah of the battery by this number. 3 / 4.2 = .71 hours, or 42 minutes to completely drain the batteries.)

http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=988

That guy might work a bit better, will get you a bit better than two hours...

 

[attchoum]

ok. now i understand...

so i need better amperage

 

[jonnythan]

Well, higher Ah, yes. The Ah of a battery is a measure of how much total power it contains.. the higher that is the longer it will last.

 

[attchoum]

thx for your help

it was easy. but when you dont know, you just don't know...

 

[2Dive4fun]

I just did a burn test and had about 2 hours of run time on my new battery pack with a 50w halogen.

Does anyone know how hard it is on the battery pack to drain it at a faster rate than the rated specs.?

If my battery pack is rated for a 3 amp discharge and I drain it at 4.5 or 8 ah, what does this due to the battery? I know it will heat up more at this rate, but other than that, what does the life cycle do?

If I drive a 75 watt 12 volt bulb at 16.8 volts, I'm thinking my new battery will run for an hour.

I ordered a dive Genie for the system. I will have it power the bulb at settings of 25%, 50% and 100%. This will allow my battery pack to run longer when I do not need 100% light.

Does anyone have the Genie in their bottle?