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 Foo Off-Topic chit chat with no general subject.

 09-11-07, 06:52 PM #1 russiankdi Senior Member Thread Starter     Join Date: Feb 2006 Location: PA Bikes: many Posts: 213 Mentioned: 0 Post(s) Tagged: 0 Thread(s) Quoted: 0 Post(s) Battery question I took an old bike light, put a switch in, and ran a battery pack as the power source. The pack contains 4 regular AA batteries. What do you think is the life span of the batteries if the bulb takes 6 volts? __________________ 1978 Schwinn Varsity Single Speed
 09-11-07, 07:50 PM #2 Michigander Senior Member     Join Date: May 2005 Bikes: Giant ATX 1200, Schwinn Peleton Posts: 1,726 Mentioned: 3 Post(s) Tagged: 0 Thread(s) Quoted: 412 Post(s) Depends on how many amps the bulb draws. For a ball park guess, it should be at least an hour or so I'd say. __________________ Bring back the Sig Test! (\__/) (='.'=) (")_(")
 09-11-07, 08:19 PM #3 nobrainer440 I play in the street.     Join Date: Jul 2005 Location: College: K-State; Home: Overland Park, KS Bikes: 2005 Allez Triple, 1971 Schwinn Varsity Fixed Gear Conversion Posts: 977 Mentioned: 0 Post(s) Tagged: 0 Thread(s) Quoted: 0 Post(s) As michigander pointed out, it depends on the amperage of the bulb. Divide the wattage of the bulb by the voltage (6V) to get the amperage. Divide the battery capacity (in amp-hours) by the amperage, and voila! Run time in hours! As a rough estimate, the capacity of an alkaline AA might be around 1 or 2 amp-hours. Note: The capacities do not add up, as all the current flows through all the batteries at the same time. Also, AA's are actually rated at 20 milliamps for 107 hours. Since your current will likely be much greater than this, the batteries will probably not perform ideally. Hopefully they will not get super hot.
 09-11-07, 08:30 PM #4 russiankdi Senior Member Thread Starter     Join Date: Feb 2006 Location: PA Bikes: many Posts: 213 Mentioned: 0 Post(s) Tagged: 0 Thread(s) Quoted: 0 Post(s) Well the bulb is 2 watts. So in amps i got .3 repeating. So i should be able to get about hours out of it, which is enough. __________________ 1978 Schwinn Varsity Single Speed
 09-11-07, 09:04 PM #5 Michigander Senior Member     Join Date: May 2005 Bikes: Giant ATX 1200, Schwinn Peleton Posts: 1,726 Mentioned: 3 Post(s) Tagged: 0 Thread(s) Quoted: 412 Post(s) One thing worthy of suggestion is rechargable NIMH AA's. They last long as hell in my camera. __________________ Bring back the Sig Test! (\__/) (='.'=) (")_(")
09-11-07, 09:17 PM   #6
russiankdi
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Quote:
 Originally Posted by Michigander One thing worthy of suggestion is rechargable NIMH AA's. They last long as hell in my camera.
I have those too, but recharging them is a problem. The battery pack is directly soldered to the light, with the exception of the positive wire, it runs into a switch.
__________________
1978 Schwinn Varsity Single Speed

 09-12-07, 12:44 PM #7 idcruiserman Mmmmm potatoes     Join Date: Sep 2006 Location: Idaho Bikes: Posts: 1,921 Mentioned: 0 Post(s) Tagged: 0 Thread(s) Quoted: 0 Post(s) Depends if the batteries are in series or parallel.
09-12-07, 01:30 PM   #8
nobrainer440
I play in the street.

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Quote:
 Originally Posted by idcruiserman Depends if the batteries are in series or parallel.
Series is assumed.