Right, I think I get what you mean.

To get 24v on 2 x 12v batteries then you have to connect em in series with each other rather than to both connectors on the Roboteq as that will just be in parallel, then just use both sets going into the Roboteq to handle the current better, although I don't see current being an issue in this case. Connecting Eric's batteries in series would give 34Ah, which is probably not required....

Think i can manage that, cheers .

EDIT: Too right Jamie, was even easier than that XXL I'm using. Definitely know which brands i'll be avoiding on future ESC purchases