Every [[NewtonMessagePad]] has the ability to use either alkaline (dry) cells or a rechargable pack as a power source, except for the [[eMate300]]. The rechargable packs can only be charged in the Newton with an [[ACAdapter]] or in the base of the 110/120/130 charging cradle. There is also the special [[BatteryBooster]], which is a different beast altogether. You can also consider [[SolarPanels]].
The [[OriginalMessagePad]] and the MP100 share battery components. They can use either a [[NiCad]] rechargable pack or a battery "cage" that takes four AAA (R03, UM-4) alkaline cells. The cage and the pack both look like a small box - the four cells stacked two by two. The AAA cages can be had for fairly cheap (a few dollars US) in some online shops - which is good, because most of these [[NiCad]] packs are almost ten years old now and have probably reached the end of their useful life.
The 110/120/130 also share the same battery components. They can use either a [[NiCad]] rechargable pack or can accept four AA (R6, UM-3) cells without need for a battery cage. The cells are arranged side-by-side. The [[NiCad]] pack is actually four AA [[NiCad]] cells which have been glued to a special frame. The frame pushes down a switch in the bottom of the battery compartment which tells the Newton that rechargables are installed, so that they can be recharged. With some careful work you can [rebuild a 110/120/130 pack](http://www.pda-soft.de/mp_1x0_battery_pack.html], or you can insert a small piece of cardboard over the switch, and then insert four AA [[NiCad]] cells. NEVER recharge [[NiMH]] cells in a 1x0 devices - they don't know how and may ruin the cells, your Newton, or both. You can use [[NiMH]) cells fine, just use an external charger instead.
The 2000/2100 models share the same battery components. They can use either a [[NiMH]] rechargable pack or a battery cage (different from the OMP cage) that takes four AA (R6, UM-3) cells. The rechargable pack has a built-in thermistor that measures the temperature of the pack and send the data to the Newton so that it can determine when the pack is fully recharged. The AA cage lacks this thermistor, so you cannot recharge [[NiMH]] cells with the stock cage. It is possible to rebuild this pack as well, but it is much harder than the 110/120/130 pack.
[[HomePage]] : [[HardWare]] : [[BatteryPacks]]