From 313c825d857b90f23f3e87738c6c87fdc24b4a15 Mon Sep 17 00:00:00 2001 From: BjĂśrn Stenberg Date: Wed, 23 Apr 2003 11:52:01 +0000 Subject: Better power calculations git-svn-id: svn://svn.rockbox.org/rockbox/trunk@3589 a1c6a512-1295-4272-9138-f99709370657 --- docs/BATTERY-FAQ | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-) diff --git a/docs/BATTERY-FAQ b/docs/BATTERY-FAQ index 201e30c660..35829a2dae 100644 --- a/docs/BATTERY-FAQ +++ b/docs/BATTERY-FAQ @@ -188,8 +188,26 @@ A12: In our testing we found the following results: HD on, reading, backlight off ~ 600 mA HD spin up before read max 800 mA - So leaving the unit on and paused consumes ~100mA, and thus much less - than needing to reboot the unit. Your mileage may vary. + Using the power draw measurements shown above, lets look at the numbers: + Power-down and restart vs. paused for 15 minutes.: + + Pause for 15 minutes will draw: 94 mA / 60 minutes * 15 minutes = + 23.5 mAh. + + Power-down and restart will draw about (800mA / 3600 seconds * 3 + seconds = 0.6666 mAh) + (600 mA / 3600 seconds * 6 seconds = 1.0 mAh) + + (230 mA / 3600 seconds * 8 seconds = 0.5111 mAh) = 2.18 mAh total used. + + Thus, leaving it paused for 15 minutes draws more power (23.5 mAh) than + turning off and then on again (2.18 mAh). + + So where is the break-even point? + + Each second of pause will draw about 94 mAh / 3600 seconds = 26 ľAh. + + 2.18 mAh / 26 ľAh = 2180 ľAh / 26 ľAh = 83.5 seconds + + Thus a shutdown and restart uses as much power as 83.5 seconds of pause. Q13: When I plug in the charger when the Recorder is turned off, it turns itself on and starts charging in the Archos software? What's up? -- cgit v1.2.3