For anyone who owns 2010, possibly a little earlier & later and has struggled with the 4 small fuses at the rear of the battery pack read on.
After having trouble with mine twice I have now replaced them. The charger one in particular does NOT seem capable of taking the current and in my case started to melt. Pic attached, hard to see but at the base near the connecting spades, you can see it has started.
This was undoubtedly caused by the radically flimsy locking tabs on the screw on cap, which in my case had lost their shape. This prevents the fuse from bedding down properly under tension, probably causing arcing.
This could lead to problems in charging, 12v circuits, 12v DC DC circuit and intriguingly the oh so troublesome contactor circuit. These all use this same fuse type.
I've replaced them all with externally mounted DC rated high current rated circuit breakers. I mounted them externally so I could replace them without removing the entire battery pack if I have problems again. Note, I'm not happy with my cable run which is a bit tight between the frame and the pack, next time I'll drill a hole and exit the rear higher up.