O2 Jet - a battery standby time analysis

I have just finished a test of the standby time of the O2 Jet handset.
O2 claims 520 hours standby time. This particular handset has been
unlocked. It's on the Vodafone network if that makes a difference to
how often the antenna is active. The battery saving option was enabled
and the screen brightness lowered. The handset screen was turned on to
check for SMS messages/errors for maybe 10-20 seconds every other day.
Two or three text messages were received during the whole time of
testing. No calls were made or received.

The mobile was first fully charged, then fully discharged & fully
charged.

The charger was disconnected at 21:35 on 5 September 2007.

The first low battery beeping noise & alert screen, which happens
maybe every 10 minutes (sometimes less often, sometimes more often),
started at:
08:51 on 18 September 2007, or T+ 299.266 hours (T+ 12 days, 11 hours,
16 minutes)

The handset finally turned itself off at:
15:58 on 21 September 2007, or T+ 378.383 hours (T+ 15 days, 18 hours,
23 minutes)

So, the battery standby time is - for me - 142 hours less than their
520 hours claim.

One thing I have observed is that about once a day the handset
disables the keylock by itself. It's as though it does a quick reset -
no O2 bootup logo is displayed, but the screen turns on and says
"Searching..." and then says the network name. I haven't tried an O2
sim to see if it makes a difference. It's possible that the unlocking
process screwed it up a little.

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› See More: O2 Jet - a battery standby time analysis

[email protected] declared for all the world to hear...
> I have just finished a test of the standby time of the O2 Jet handset.
> O2 claims 520 hours standby time.

I think you will find it says "Up to 520 Hours"

> The mobile was first fully charged, then fully discharged & fully
> charged.

A new battery will need a good 5-10 cycles to get it up to full
capacity.
--
Regards
Jon

There are a few variables to take into account when making a standby
time test not including the condition of the mobile phone battery and
other functions enabled/disabled on the mobile.. The standby time
quoted is the maximum (up to), not an average.

External variables:

Proximity to the local BTS
Depending on distance to the BTS, a class 4 mobile will vary it's
power under control of the BSC/BTS.
For 900 MHz this is between 5 - 33 dBm (3.2 mW to 2W)

Periodic update (T3212 timer)
The mobile on standby will send a periodic update if it does not move
from it's existing location area code, this is a variable set by the
mobile operator and with O2 this is every 3 hours. Not sure with
Vodafone, may be the same .

Proximity to location area boundary.
If the mobile is on standby and in the boundary of a location area
there may be transmissions from the mobile to update the BSC of the
location area if it changes. This should not vary if the mobile is
truly static but if in a poor signal strength area may initiate
spurious updates as signal strengths from BTSs in adjacent location
areas vary due to movements of bodies, vehicles, swaying trees etc.

Best case - The mobile is very close to the BTS well within a location
area, periodic update is every 24 hours and when it transmits it's at
5dBm (3.2milliwats). - Standby time is maximum

Worst case - The mobile is in a very poor signal strength area in the
boundary of two or three location area, periodic update is every 30
minutes and when it transmits it's at 33 dBm (2 watts) - Standby time
is minimum.

If you are getting 299 hours and you are not in either of the extremes
above then I would consider this the average standby time for the
location it was in.


On Fri, 21 Sep 2007 15:26:38 -0000, [email protected] wrote:

>I have just finished a test of the standby time of the O2 Jet handset.
>O2 claims 520 hours standby time. This particular handset has been
>unlocked. It's on the Vodafone network if that makes a difference to
>how often the antenna is active. The battery saving option was enabled
>and the screen brightness lowered. The handset screen was turned on to
>check for SMS messages/errors for maybe 10-20 seconds every other day.
>Two or three text messages were received during the whole time of
>testing. No calls were made or received.
>
>The mobile was first fully charged, then fully discharged & fully
>charged.
>
>The charger was disconnected at 21:35 on 5 September 2007.
>
>The first low battery beeping noise & alert screen, which happens
>maybe every 10 minutes (sometimes less often, sometimes more often),
>started at:
>08:51 on 18 September 2007, or T+ 299.266 hours (T+ 12 days, 11 hours,
>16 minutes)
>
>The handset finally turned itself off at:
>15:58 on 21 September 2007, or T+ 378.383 hours (T+ 15 days, 18 hours,
>23 minutes)
>
>So, the battery standby time is - for me - 142 hours less than their
>520 hours claim.
>
>One thing I have observed is that about once a day the handset
>disables the keylock by itself. It's as though it does a quick reset -
>no O2 bootup logo is displayed, but the screen turns on and says
>"Searching..." and then says the network name. I haven't tried an O2
>sim to see if it makes a difference. It's possible that the unlocking
>process screwed it up a little.