 Most notably, the covers of the LCD screens and the digitizers were plastic rather than glass, and the screens were smaller than the more expensive Palms on sale at the time.Unlike other Palm computers, which had rechargeable batteries, they were designed to run on standard dry cell batteries (except for the m130, which uses a rechargeable battery).Data preservation occurred via a backup battery system that had a very short life and high voltage volatility, such that users had to change dry-cell batteries one at a time; users who removed all the batteries and then replaced them all could find that the backup battery had died in the time that it took to change the batteries, resulting in loss of unit memory.