pa49
Senior Member
- Nov 29, 2010
- 365
- 38
I have been checking out a few things and my findings may be worth bearing in mind.
Using a power consumption program ( PowerTutor ) and with GPS, WiFi, LCD and obviously CPU all enabled the total power draw I have observed at surge is approaching 2000mW (ie 2W).
Note that this is without any 3g, BT, audio or video usage ( I will try and obtain these levels separately ).
These levels by themselves cannot be converted to current draw, however as we know the Lithium Ion voltage ( which I will take as 4.5v ) then the current can be calculated by A=W/V.
This gives us A=2/4.5 = .4444mAh
That's nearly 500mAh current draw without using the phone functions or BT!!!!!
Power on transmit (depending on frequency, 2g/3g etc) can be up to 500mAh+ as well so at any one time the device could require in excess of 1Ah in order to operate (remember that's without BT and also without taking in to account any other running apps that would also consume higher power levels via CPU usage.
Any supply of less capacity would struggle under these conditions to simply keep the device working never mind charge it at the same time.
The result would be a build up of heat in the supply and definitely be worth avoiding for safety's sake.
There could also be the risk of damage to the device.
Anyway, I will stick by all I originally stated, others can decide for themselves.
Using a power consumption program ( PowerTutor ) and with GPS, WiFi, LCD and obviously CPU all enabled the total power draw I have observed at surge is approaching 2000mW (ie 2W).
Note that this is without any 3g, BT, audio or video usage ( I will try and obtain these levels separately ).
These levels by themselves cannot be converted to current draw, however as we know the Lithium Ion voltage ( which I will take as 4.5v ) then the current can be calculated by A=W/V.
This gives us A=2/4.5 = .4444mAh
That's nearly 500mAh current draw without using the phone functions or BT!!!!!
Power on transmit (depending on frequency, 2g/3g etc) can be up to 500mAh+ as well so at any one time the device could require in excess of 1Ah in order to operate (remember that's without BT and also without taking in to account any other running apps that would also consume higher power levels via CPU usage.
Any supply of less capacity would struggle under these conditions to simply keep the device working never mind charge it at the same time.
The result would be a build up of heat in the supply and definitely be worth avoiding for safety's sake.
There could also be the risk of damage to the device.
Anyway, I will stick by all I originally stated, others can decide for themselves.
Very frustrating to say the least. After I had my tablet downloading my books I found the post about this very thing. If this info is easier to find, maybe I can spare the next poor reader.
