Car Batteries discharge rates

[television]

Car batteries are made to cycle 10 to 15% of their total capacity.

The amp hour ratings for car batterries is difined over a 20 hour discharge period (evenly discharged) so to know how much current the battery can give

example Battery 75 amp hour rating, divide by 20 = 3.75, that means this battery can give 3.75 amps for 20 hours. A 55 amp hour will give 2.75 over the same period.

Modern cars run from the alternater and not the battery.

Malcolm

 

[dogsbody]

Car batteries discharge rates

I am not sure I agree with you! Car Batteries are supposed to deliver a high amperage for a short period of time, and are not designed to give steady discharges over long periods.
My boat has one 75 amp car battery to start the diesel engine. It has 2 x 110 amp deep cycle batteries designed to keep all the electrics and electronics going for a period of days.
If you crank the engine repeatedly without it firing, the battery becomes discharged quite quickly. The deep discharge batteries will not start the engine, but they will run the fridge( beer cooler) at 5 amps /hour for 2 days

 

[television]

I am not sure I agree with you! Car Batteries are supposed to deliver a high amperage for a short period of time, and are not designed to give steady discharges over long periods.
My boat has one 75 amp car battery to start the diesel engine. It has 2 x 110 amp deep cycle batteries designed to keep all the electrics and electronics going for a period of days.
If you crank the engine repeatedly without it firing, the battery becomes discharged quite quickly. The deep discharge batteries will not start the engine, but they will run the fridge( beer cooler) at 5 amps /hour for 2 days

The figures I laid out are those given out by car battery manufactures to determin the size of the battery for a particular vehicle. Obviuosly they take into account the starting of the vehicle, but this is put back quickly by the alternator, and as I said, cars run on the alernator, not the battery.
The new E class uses a different type of battery altogether as does the F1 pace car

Malcolm