2006-11-10 05:16:58 · 5 answers · asked by who cares 1 in Science & Mathematics ➔ Engineering
1.) The battery contains 4 amp hours of electrons. This means it can be drained at the rate of 1 amp per hour for 4 hours.
2.) So, if you are only draining it at the rate of 1//4 amp per hour it will last 4 times as long or 16 hours.
3.) Just think of a battery as a bucket full of water e.i. The slower you pour it out the long it lasts.
2006-11-10 05:36:25 · answer #1 · answered by HeyDude 3 · 0⤊ 0⤋
16 hours. The Ah stands for Ampere-Hours. You take the Ah rating and divide by the number of amps to get the number of hours.
This is only an approximation. As the battery loses electricity, the voltage will drop. If the device has strict voltage requirements, it might stop working earlier.
2006-11-10 13:24:19 · answer #2 · answered by Rambo Smurf 4 · 0⤊ 0⤋
Batteries are usually rated at a 20hour rate. That means it will give you the full 4Ah IF you take 20 hours to discharge it. 4Ah/20h=.2A You need .25A, which is higher than a 20h rate so the total capacity will be a bit less. Without seeing the discharge curves of your battery, I'd estimate 14-15hours.
2006-11-13 03:13:18 · answer #3 · answered by charley128 5 · 0⤊ 0⤋
In theory, 16 hours. In practice, it depends on how much the output voltage falls and how sensitive the powered device is to the voltage drop. The available energy will be less in cold temperatures, also.
As a rule of thumb, you can safely count on at least half of the theoretical value, and usually go to 75%.
2006-11-10 15:23:20 · answer #4 · answered by injanier 7 · 0⤊ 0⤋
under no load or at the minimum load; 16 hours
2006-11-10 15:02:06 · answer #5 · answered by pahump1@verizon.net 4 · 0⤊ 0⤋