Battery saving mode accuracy sacrifice?

Wanted to find out how long my eTrex Legend would run on 2500 mAh
rechargeable batteries in regular and battery saving modes, so I put
the eTrex out on the balcony and ran the batteries flat in each mode.
Here are the results for a GPS that didn't move an inch:
        
                        Regular mode                Battery saving mode
Run hours                16 hr 31 min                22 hr 12 min
Moving time                2 min 49 sec                28 min
Moving distance                0.02 miles                1.13 miles
Moving average speed        0.4 mph                        4.3 mph        
Overall average speed        0.0 mph                        0.1 mph
Max speed                1.9 mph                        4.3 mph

Interesting factoids, aren't they; but I haven't any idea about their
significance except that the battery saving mode does indeed run the
eTrex 6 hours longer at the sacrifice of accuracy.

I did this because I'm going to spend long days on a canoeing river
trip and I want the batteries to last as long as possible. Now I'm
wondering how much accuracy I'd loose in the battery saving mode over
a 10 hour day of paddling?

Any ideas?

Mike Fox
San Antonio, Texas

wrote:


Mike,

the fundamental idea is that 16 hours are well enough for most
purposes, and you need one or two sets of spare batteries
anyway, so why bother with the battery saving mode?

I have disabled that mode on all my GPS receivers since I have
these wonderful 2,500 mAh rechargeable batteries.

Hans-Georg

--
No mail, please.

you'll lose much more precision than you lost on your balcony. In battery
saving mode, the front end part of the receiver is suspended for some
seconds whenever the software expects no moving, or a constant moving within
the next few seconds.

For this reason, you'll either get no significant battery saving because the
unit expects that you'll change your direction all the time, or you'll lose
significant corners from your track.

So I recommend not to use battery saving mode in your case. Take some more
batteries with you.

--

Heinrich
http://www.gartrip.de

On 12/07/2005 11:28 AM, Mike Fox wrote:


Unless you want to record a very accurate track, why bother leaving it
on at all for long periods? And on a river trip isn't the "track" more
or less obvious anyway? How far can you deviate from the river? I've
done river trips up to 4 weeks long using a single set. I haven't ever
felt the need to keep the thing turned on 24x7. A few minutes a day is
more than enough.

Doug Payne wrote:

Try to keep the canoe between the banks of the river, and switch the GPS
off.