Question

battery information
various pieces of information are stated on a battery. for example:
12 v / 60 ah / 620 a

• 12 v: voltage.

this is a 12 v battery

• 60 ah: capacity.

this is the maximum amount of electrical energy that the battery can deliver continuously for 20 hours before it reaches a final voltage of 10.5 v at an ambient temperature of 77°f ± 3.6°f (25°c ± 2°c). if you divide 60 ah by 20, then you know how much current the battery is able to supply over this time period. in this case, the battery is able to supply 60/20 = 3 amps for a period of 20 hours.

• 620 a: cold start current.

according to the sae standard, this battery is able to supply 620 amps for 30 seconds with a final voltage of 7.2 v at an ambient temperature no less than 0°f (-18°c).
how many amps is this battery pictured above to deliver for a period of 20 hours?

Explanation:

Step1: Calculate current

Current \( I=\frac{Capacity}{Time} \). Given capacity \( C = 60\ Ah \) and time \( t=20\ h \).

Step2: Substitute values

\( I=\frac{60\ Ah}{20\ h}=3\ A \)

Answer:

\( 3 \)