i know this is an old thread just though i'd throw in my 2 pence worth.
i seen many an aarm sysem burst into flames due to a short on the battery leads caused by so called 'engineers' being inexperienced, careless or just plain stupid
a fuse is to protect the wiring to, not the device it supplies - a common misconception because wire is relatively cheap in comparison to the device, so why protect it people think?, hence a fuse in a 13amp plug top as well as fuse/s inside you telly/radio would sem over kill to the uninitiated.
trust me it makes very sound sense safety wise to have fuses/breaers at the earliest point of power take off, or you risk sitting on the equivalent of a naked toaster should a short occur in the wiring prior to the fused control box
if want to prove a point? drop some coins in your pocket then drop Duracel PP3 in on top, count how long before your hopping about and dropping your strides in sheer panic
and thats only a few amps @ 9volts
earlier it stated the Sinclair Motor can draw 100 amps on stall, if the battery is shorted it can deliver several hundreds of amps, easily more than enough to start a fire, not a good thing to happen in a mainly plastic vehicle, especially if traveling in traffic.
a simple standard wired fuse may well blow regularly, so perhaps anti surge or slow blow could be used, the resettable thermal type as used on washing machines could employed but getting such a high amperage might be an issue.
thought i'd just clear that up for future readers
regs
alan
///puts soap box back in cupboard