This article describes the technical specifications parameters of lead-acid batteries. This article uses the Eastman Tall Tubular Conventional Battery (lead-acid) specifications as an example.

Electrical Parameters & Charging Profile

Battery Specified Capacity Test @ 27 °C and 10.5V

C Rating

The most important aspect of a battery is its C-rating. This value is dependent on temperature and current draw. In the above table, you will notice C-ratings of C20, C10, C5, C3 and C1.

The battery's C rating is its perceived capacity when the battery is fully discharged during the period of time.

For example, consider the EM100 battery above at 27℃.

• C20: 100 Ah - The battery will supply a 5A current through 20 hours (5×20=100)
• C10: 90 Ah - The battery will supply a 9A current through 10 hours

Maximum Charge Current

This is the maximum current advised to charge the battery. We should not exceed this value. However, I recommend you charge the battery much slower. The charge current is usually specified as a percentage of a C-rating. For example, the Eastman Tall Tubular Conventional Battery's maximum charging current is 0.2C10.

EM220 battery as an example has a maximum charge current of 0.2C10.

• Expression: 0.2C10 = 0.2 × [C10 Rating]
• C10 rating at 27℃ = 200 Ah
• Maximum current = 0.2 × 200 = 40A