On Mon, 3 Apr 2000, Dave Storrs wrote: > Haha! *Finally*, a question I can answer. > > John, I'm using that exact board (PCM-5820E, the E meaning it's > the low power version). It draws 5V @ 1.45A, which is (5 x 1.45=) 7.25W. > The batteries you describe contain (9.6V x 1Ah = ) 9.6Wh. Therefore, one > of those batteries will drive the board for approximately 1 hour 20 mins. > > The key formula to know (which someone on this list was kind > enough to share with *me* not too long ago) is V(olts) x A(mps) = W(atts). > Batteries always want to measure their capacity in mA (milli Amps) but > just divide by 1000 to convert to Amps. > > Dave This is true in general. However, the efficiency of the power supply will also affect battery life, as well as how hard you run the computer, use of apmd (advanced power management daemon), etc. Also, some power supplies will cut out when the battery voltage goes below a certain level, so there will be power left in the batteries you can't use. So the 80-minute figure is correct as a general figure but in practice you should get a bit better perfromane in the average case and a bit worse in the worst case. -- Subcription/unsubscription/info requests: send e-mail with subject of "subscribe", "unsubscribe", or "info" toWear-Hard Mailing List Archive (searchable): http://wearables.blu.org
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