[JASJAR, XDA Exec, MDA Pro General] Menneisyys:
It was a few days ago that I’ve published some test results of the HTC Wizard (a.k.a. i-mate K-Jam, T-Mobile MDA Vario, Qtek 9100, MDA Vario, XDA mini S, SPV M3000, VPA Compact II, Dopod 838), Bluetooth and infrared power consumption-wise. Now, the HTC Universal follows suit.

Bluetooth

First and foremost, the case of the Universal seems to be very similar to that of the Wizard: that is, it’s almost impossible to measure the additional power consumption of the Bluetooth module. The difference between the switched on and the switched off case was 1% (at most!) a day (if at all).

This, incidentally, corresponds to my measurements of the BT unit with the PDA switched on. According to my measurements, the BT unit burns between 1 and 2 mA’s in those cases. This, as the device has a 1620 mAh battery, corresponds to between 800 and 1600 hours battery life alone - that is, not taking into account the need to power the dynamic RAM, which is pretty much the same as with the HTC Wizard, which is around 1.25 mWh corresponding to about 2% battery level drop/day (don’t forget that the Wizard has a smaller, 1250 mAh battery; this is why it had a bigger, 2.5% battery charge level drop figure).

Infrared

The same stands for the infrared unit: when switched on, the device consumes about 1% more a day (as opposed to about 1.5% on the Wizard; again, the latter is because of the smaller battery used in the Wizard) – that is, the power consumption of the unit is around 0.8 mWh (just like with the Wizard).

Again, with Pocket PC Phone Edition devices, the Bluetooth and the infrared unit is always on, as opposed to "plain" Pocket PC devices, and actively listen to incoming requests. This is why a desktop Windows device (for example, a notebook equipped with an infrared port and running Windows XP) notices Pocket PC Phone Edition devices at once as an infrared modem (see this screenshot) - or, for that matter, any WM5+ non-Phone Edition Pocket PC devices when not suspended (again, the wireless units of non-Phone Edition Pocket PC devices are only activated when they are on, as opposed to Phone Edition devices).

This is certainly very good news and shows the two devices may use exactly the same Bluetooth / infrared modules & hardware drivers & for example code to listen to incoming infrared requests.

How much power does the GSM radio consume?

Incidentally, I’ve also run a lot of tests to correctly measure the power consumption of the phone module itself with a removed SIM card (to avoid for example incoming calls’ having an adverse effect on battery life; the device was all the time connected to the phone network to be able to start emergency calls any time). It’s about 9%/day at a given location.

Don’t forget that this value is pretty meaningless when used as an absolute measurement: on other locations (for example, far closer/farer from a cell center (with far better/worse radio field strength) the figures would have been entirely different. It’s, however, offers great relative measurement possibilities: I’ll measure the power consumption of my other Phone Edition devices to see whether their phone radio unit is better/worse, power consumption-wise. I’ll publish some Wizard-related results soon.

Verdict

All in all, it’s only when you almost never use your Universal as a PDA (that is, switch on the screen and run something) that there will be ANY difference in the battery life between the enabled and disabled wireless state.

If you switch on the PDA a lot, play games on it and/or receive/initiate many phone calls a day, the additional power consumption of the Bluetooth / infrared unit will be totally negligible. (Let’s point out again and again that the PDA unit in the Universal is really-really power-hungry. While the Wizard – or, for that matter, power-sparing devices like the Pocket Loox 720 or the HP iPAQ hx4700 – only need to be recharged every second or third day with moderate PDA use, the Universal needs to be recharged far more frequently if you often use it as a PDA.)