Here's some interesting info I've found relating to direct push. In the KB
article below it states that the default setting for 'maxheartbeatinterval' is
45 minutes. So if nothing is set in the registry, this is supposed to be the
value used. We have seen a large increase in battery consumption when upgrading
our devices to a rom with direct push.... in the nature of 30-40% reduction in
run time. This didn't make sense to me considering how often the device was
syncing (about 140 messages a day, maybe 10 minutes of voice time) so on a hunch
I manually set the 'maxheartbeatinterval' to 45 minutes. Since making this change,
my battery life has gone from 10-12 hours per charge to 24-26 hours per charge.
I've verified this change on two different devices (a PPC-6700 and a 700W) so
there must be something to this setting. It may be that the setting is forcing
Exchange to use this setting irregardless of the network conditions but I have
seen no adverse effects of changing this. If you have seen similar decreases in
runtime, try this change and let me know your results.