p vs h-series batteries

The old P-series battery has a smaller mounting slots than the newer InfoLithium H-series ActiForce (shorter charge time, last longer, but same voltage, current?), supposedly the charger would work on both, and older p-series camera can take both, but newer camera cannot take the older P-series?

photo of p-series battery

p-series batteries

photo of p-series camcorder

p-series camcorder

photo of h-series battery

h-series battery photo

photo of h-series camcorder

h-series camera