Any updates on this mate?Yes, I did purchase the Lithium batteries. They are in transit and I plan to do the swap myself when they arrive. I just pulled out the back seat and cleaned the blower fan to minimize downtime.
I checked my battery and it's at 49% health, which is pretty poor, the difference in voltage between blades is quite high. I expect to get a CEL soon and cant imagine what a strain it has put on my ICE. My options were to replace the bad cell (the #7 blade) and rebalance and hope the rest of the cells last a bit longer, rebalance the whole system (takes 3 days and costs @ $500-900), purchase new NiMh, or upgrade to LiFePo4 (Nexcell). I chose the last option. Why, because LiFePo4 is half the weight, more energy dense, and newer, cleaner technology(from manufacturing to use to recycling). It also has no off-gassing of hydrogen like NiMh. Quite a long list of pro's.