Battery considerations were important to me when I finally decided it was time to try a PDA. The form-factor of the m50x (thin and small) was a strong draw, so I compromised by going with the m500 vs m505, reasoning that the monochrome display would be less power hungry than the color one.<br><br>My concerns about battery life were soon put to rest.<br><br>In regular use my m500 easily (and routinely) goes two weeks with battery to spare, using no energy conservation measures. It for sure can go longer. If it was really important, I think it would be almost trivial to make a sled to use drycells for power. The transformer for the docking stations indicates a regulated output of 5vdc. A sled with 4 dry cells and less than $2 of off-the shelf parts (excluding the connector) would do the trick. With a little more effort (and a few more components) it could be done with fewer dry cells.<br><br>There are inexpensive solar rechargers readily available that handle 4 AA/AAA cells.<br><br>But to me, battery life is not anything to be concerned about in a survival situation. If the PDA survives whatever precipitated the situation and it has pertinent useful info on it, use it. If not, or if the batteries exhaust, do without. <br><br>An extended trip (intentional) with the PDA (and a folding keyboard) used for journal entries, reference, whatever is different. Then the rechargables vs the AAA powered might be important. A compromise Palm model, if one wished to use replaceable dry cells, is the m125. I imagine there are similar models in the other lines of Palm OS PDAs.<br><br>Meanwhile, I prefer to NOT do without my PDA, as others have stated. If I had listened to my brother more closely years ago... I had no idea how truly useful it would be until I (almost reluctantly) got this one several months ago.<br><br>just my 2 cents worth on PDAs and battery life<br><br>Scouter Tom