I'm considering mounting my battery in the compartment at the rear of the seat. (FST) The only way to do this would be to lay it on its side. The battery says it is a sealed, non-spillable type. Assuming I can secure it properly, is it ok to lay on its side? OEM mounting near the clutches has it slightly tilted. Thanks.

Man, not liking that idea, just doesn't sound right. Maybe if it were a gel cell?

Gotta agree - even if it is a sealed, maintenance free type battery, the caps can still come off and spill battery acid.