The original battery on my ST4 lasted for 4 years, using a monthly trickle charge over the winter to keep it topped up. It finally gave up the ghost when it wouldn't maintain voltage when running, I assume a suplhated up cell and the bike went into limp home mode. The replacement was a genuine FIAM one and that lasted 10 months! That one was kept topped up with an Optimate as well. Replaced free of charge by dealer. |