The peak is the part that must work ok. (will work ok) It is the rate or current that will be minimised.

The digital piranha is one of the worst chargers for current when it comes to higher cell count batts, lots of people will notice this even on 6-7 cells. It is real bad on 8 cells (which is within the specs) and even on ac or dc will drop off to 1 amp or so.

Running this charger on a nice 15 volt ps really makes a nice charger out of it. It will allow the rate to come right up to 5 amps, the 15 volt power supplies are readily available and cheap too because a lot of notebooks use them. You only need abouit 60 watts.