Question

Design a battery to be constructed of D-cells, rated at 3Amp-hours and voltage 1.5V, that will provide a maximum operating current of 5.0A with an emf of 4.5V. One restriction is that no cell be required to supply in excess of 1.0A. What can you expect the lifetime of your battery to be while delivering maximum current

Answer 1

Answer:

9 hours

Explanation:

For each battery:

Current = 1 A

Voltage = 1.5 V

current and EMF required = 5.0 A and 4.5 V

Since each battery has a current of 1 A, we'll need to link five of them in parallel with our load to get a current of 5 A. so that the total current equals 5 amps . Now that each battery has a 1.5 V voltage drop and we require an emf of 4.5 V, we would use three batteries in series rather than a single battery.  So, there is a need to must substitute every single battery with three batteries in series for all five single batteries linked in parallel.

So, the total no. of batteries is

= 5 × 3 = 15 batteries.

On each battery, the charge is = 3 amp hours

∴

The total charge = 15 × 3 = 45 amp hours.

Since the charge transferred within 1 hour = 5 amp

Then, the required lifetime of the battery is:

= 45 amp-hours/ 5 amp

= 9 hours