Im guessing the 360W will effectively halve in value for each part of the clusterbot seeing as its only half the weight, so its only likely to need 180W (maybe 200W?) to accelerate each half of the cluster - hence at 12V youre looking at pulling approx 15A per channel. I wouldve thought the current limit for a 10A channel speedo would be higher, although admittedly Im not the most clued-up person about this sort of stuff