Ya, some chargers these days, the lowest mV setting is to high for todays 3800/4200's I remember setting my pulsar competition at 5-10mv per pack in the 90 degree summer time cause they were getting to hot. then generally 15-20mv per pack for indoor chargin.
I recently got a Orion Advantage Carbon Charger. It has a lowest setting of 3mV per cell, which is 18mV for the hole pack. It seemed pretty good. But in the summer time, i will have to have teh temp probe plugged in to cut it off at about 125 degrees though.
Some chargers measure teh mv setting per cell, and some mv per pack, so make sure. GP's tend to use a higher mv setting
TLR ~ MaClan ~ Hobbywing ~ Futaba ~ Proline ~ Werks Racing ~ Genesis R/C Products ~ Mr. Scrubbles ~ First Premier Satellites