Don't know if this is normal, but a friend had a Torqueedo rigged on his Raptor. He was plagued by battery problems the whole time he had it (and replacement battery cost is guaranteed to cause cardiac arrest), and they always want you to send the whole unit in to them along with the battery for testing when there is a problem. After a while he got tired of dumping money into an unreliable system that was always in the shop, and bought a SoloSkiff.
I have no idea if he just got a lemon, or if they are all like that. Might research it before investing in a Torqueedo, just to be safe.