Major power concern

[Pia Waugh]

Hi all,

I've just noticed that release candidate 765 when fully charged tells me I
have 2 1/2 hours of usage. This is a major concern, and something we really
need to fix for this release. As I tested it, it appeared to get about a
minute or two to each percentage of battery. Below are some initial results
as I know people want them sooner rather than later :)

I was asked in #olpc to see if ohmd is running. It is. Anything else I can
check for? I found that by default the "power savings" option was turned
off. I turned it on for one of the test laptops below.

All laptops were simply turned on and the mouse hovered over the battery
symbol for status, no apps were run nor other activity run.

The % is the indicated remaining battery time.

Test 1 - default 765 image

    765 started at (98%) fully charged
    64% 1.48hrs remaining @ 65 mins running time
    50% 1.24hrs remaining @ 98 mins running time
    45% 1.16hrs remaining @ 108 mins running time

    Estiamted time = ~2 1/2 - 3hrs

Test 2 - default 765 image but with power savings on

    765 started at (93%) mostly charged with power savings turned on 
        and rebooted
    93% @ 0 mins running time
    92% @ 2.35 10 mins running time
    90% @ 2.32 35 mins running time
    90% @ 2.32 41 mins running time
    90% @ 2.32 50 mins running time

    Estimated full time = ~10hrs+

Test 3 - default 711 image

    711 build started at (97%) fully charged (no percentage available)
    94% @ 10 mins running time
    89% @ 23 mins running time
    84% @ 35 mins running time
    73% @ 68 mins running time

    Estimated time = 4-5 hrs

Please note these are initial results and I won't know for sure until
another few hours for the first round, and a few repeats, but at least this
gets other able to start testing :)

This issue could be a major problem for this new release and if unfixed
would seriously undermine the awesome efforts of all involved in the great
changes for 8.2.0.

Just for reference I've seen trials for primary schools with other devices
and one of the main benefits of the XO over them was better power, so we
need to maintain that :) If you are interested the other main reasons were
screen size, the ease of prepacking a full suite of apps/content, the
relative cost of the wireless infrastructure needed, and the community
around OLPC.

Cheers,
Pia

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