We left out the voltage of the battery and only focused on the ampere-hours for its capacity. Both the 12V 10Ah battery and the 6V 10Ah battery can power a receiver using 1A current for 10 hours, but in the case of 12V the receiver will use 12W and in the case of 6V it will be a 6W receiver. Therefore, the capacity of the batteries is often specified in Wh, i.e. a 10Wh battery can supply a receiver with 1W power for 10 hours. The aforementioned batteries have a capacity per Wh, respectively: battery 12V 10Ah -> 120Wh, while 6V 10Ah -> 60Wh. You will also find watt hours, or rather kWh, in electricity meters in the home power supply system.
Information about the basic parameters such as voltage, current, power, more information can be found here: Voltage, current, power - what are these values and how are they related by Ohm's law?
Cool? Ranking DIY