Correct me if I am wrong but AFAIK, the main problem is a mains charger with a "recondition" function which "pulse" charges at 16 volts.
This is too high for a lithium battery and will cause overheating and possible fire.
Most bike lithium batteries have an inbuilt Voltage (or charge) Regulator to drop the bikes output down from 14+ volts to 13.2 or something like that which is ideal for lithium batteries.
To the best of my knowledge, a standard (non multi-stage) old fashioned battery charger should be fine if the lithium battery has an inbuilt regulator.
I believe that even the inbuilt regulators in the lithium batteries cannot handle the "recondition" function.
Macka