The Hotronic Power Plus m4 has four cells in each battery pack, and is Hotronic’s most powerful, longest lasting Battery Pack ever!

Hotronic m4 Power Plus Temperature & Duration Chart
Heat Setting	Approx. Avg. Temp.		Duration Range
1	83 - 89 °F	28 - 32 °C	19 - 21 hrs
2	96 - 106 °F	36 - 41 °C	7 - 9 hrs
3	105 - 116 °F	40 - 47 °C	5 - 6.5 hrs
4	135 - 144 °F	57 - 62 °C	2.5 - 3.75 hrs

HOTRONIC m4 POWER PLUS BATTERY PACK