How long will a 30Ah battery last with a 850mA per hour draw?

To calculate how long a 30Ah battery will last with an 850mA draw, you can use the formula: Battery life (hours) = Battery capacity (Ah) / Current draw (A). First, convert 850mA to Ah, which is 0.85Ah. Then, divide 30Ah by 0.85Ah, resulting in approximately 35.3 hours. Therefore, the battery will last around 35 hours under a continuous 850mA draw.