Measuring Lead-Acid Battery Capacity

After putting a lead-acid battery to use, you can calculate its remaining capacity using the following formula:

$$B_{Pb} = \frac{100 \cdot I_L \cdot t}{(100 - Q)(0.02t + 0.6)}$$

• B_Pb – Remaining capacity of the lead-acid battery (Pb because it's the chemical symbol for lead)
• I_L – Load current
• t – Duration for which the power is supplied to the load
• Q – Percentage of charge that should remain after the battery is used

Checking Lithium-Ion Battery Capacity After Use

For a lithium-ion battery, the formula for the battery capacity is:

$$B_{Li} = \frac{100 \cdot I_L \cdot t}{(100 - Q)}$$

• B_Li – Remaining capacity of the lithium-ion battery (Li because it's the chemical symbol for lithium)
• I_L – Load current
• t – Duration for which the electrical power is supplied to the load
• Q – Percentage of charge that should remain after the battery is used