As I said, if you are using an external power supply for the AMBrc system, you can use it for the charging rack instead. My previous message explained that the external power supply is optional for the AMBrc system, freeing it for use for the charging rack.
Without knowing more details about your situation, I can't give any further advice. It should be easy to find a wall wart or generic brick power supply somewhere either locally or on the 'net should you need to replace it.