For NiMH packs delta peak is usually set at 5 on your MRC. Try setting the amps to lower than maximum. Maxxing the amperage tends to trigger false peaks.
With the pirahna it probably doesn't matter what you set it at. Just keep restarting the packs when they false peak until they hit 120 degrees farenheit.
If your packs have been in storage for longer than 6 months, they'll probably require several cycles to come back to normal behavior. The first cycle should be at low amps (1-3).
GV2 Pro, XXX4G+, Blitz SCT, CRC GenXL