Im confused! I want to use my gel cell small light weight 12 volt 7ah/20h battery for my 45 amp electric outbord if my calculations are correct then 7ah multiplyed by 20hour equals 140 amphere battery,and if my electric outboard draws constint 45 amps than my 7ah/20h battery should last 3.11 hours (45amps divide 20 hours) equals 3.11 hours (AM I CORRECT IF NOT WHY) THANKYOU FOR YOUR HELP...
2007-11-12 13:09:51 · 2 answers · asked by Anonymous in Science & Mathematics ➔ Physics
t= 7x20 /45=3.1 confirmed in rough theory that is.
However it is not that simple.
Since you do not know the rating of the battery at higher current levels. Look at the discharge curves for that specific battery.
2007-11-12 13:14:36 · answer #1 · answered by Edward 7 · 0⤊ 0⤋
No, it's a 7 amp-hour battery. The 20 h refers to the discharge time at which battery capacity is rated. It means that the battery will put out 7/20 amps for 20 hours. So it will provide 45 amps for considerably less than 7/45 hr = 9.3 minutes. I say less because the capacity is reduced at higher currents.
2007-11-12 21:32:08 · answer #2 · answered by injanier 7 · 0⤊ 0⤋