On Feb 7, 2009, at 7:33 PM, Funny NYPD wrote: > I'm currently using a Tadiran TL-5955 Lithium battery > >: > 1.5Ah, max. pulse 150mA, 2/3AA size. > > I thought that this type of battery has a voltage that's rather > independent of charge state until it is almost dead. But what I find > is > that the voltage under 55mA load dips below 2.8V much earlier in the > lifetime than I expected, considering the battery capacity and the > current consumption. That does seem pretty counter-intuitive; it's a 3.6V battery after all... Have you confirmed the current draw/etc? It'd be more understandable if you're exceeding that 155mA spec. (and have you talked to tadiran?) Alternatives might include the CR2 "photo" batteries, but since those are 3V, you'd almost certainly need a boost converter to keep voltages above 2.8V. Or perhaps the Li-ion rechargeable CR2s, which are up near 4V (but are likely to have much less capacity, given that they're rechargeable.) And I think the CR2s are a bit fatter than an AA. (I don't know that there are are "popular" 3.6V consumer batteries.) BillW -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist