The charging power is designed to go to the batteries first. The batteries then feed the power to the Mark 2 AC.
The max charging current accepted by each Mark 2 Battery is about 5.5A, and the max current consumed by the Mark 2 AC is about 10A. If two batteries are connected powering the Mark 2 AC whilst charging by the power adapter, the Mark 2 AC will always have sufficient power, and the batteries will be fully charged.
However, if only one battery is connected powering the Mark 2 AC whilst charging by the power adapter, the battery will drain out.
If the battery is fully charged, it can last 5 hours powering the Mark 2 AC without charging, with the extension dock charging by the power adapter, it can last around 10 hours.
Use 12V to 24V Converter and Power Extension Dock together. The 12v cigarette socket can not charge through the expansion dock for both batteries. Damage may result from incorrect usage.
Accessories of Mark 2 do not support the 30-day return policy.