Lipos and NiMh are different profiles of recharging.
Lipo charge up with capacity you set on your charger, i.e. 5100mah, set your charger at 5.1amps. Charger starts up at 5.1 amps, and during charge up ,it will drop to 1amp, and then shut off. Its finished charging.
NiMh would start up at 5.1 amps, charger would sense it reach 5100mah then shut off. Probably stops charging at approximately 4700mah. Recharging completely discharges NiMh below .9v, will charge up to 5000mah. minus the 100mah. Most NiMh chargers shuts itself off than goes into trickle charger, to top the capacity of your battery pack. Most NiMh chargers Trickle charger ar adjustable, .5v to 1v, my setting are at .5v.
Lipos charge up at higher amperage then drops the amps during charging to top it off in amps and voltage, then shut off at 4.2v per cell.
NiMh charges up to 2/3rds of capacity, then trickle to capacity. Your best battery pack, use it when racing top it off useing trickle. Lipo can be charge up anytime. NiMh are better to discharge them to .9-.5volts or when recycled. Lipo when you balance. Put it this way, useing trickle on NiMh, is like Balancing does for Lipo's