Android Tablets Forum banner
1 - 8 of 8 Posts

·
Registered
Joined
·
187 Posts
Discussion Starter · #1 ·
I changed my wireless TXPower to 20 and basically my connectiob in the house didn't change. I can still stand in the same spot as before and about 2 foot further connection is lost. TXPower at 100 vs 20 same spot in the house. SO I decide to test how much power my M003 is pulling with wifi hack to 20 vs 100. PROCEDURES. Eken internal battery dead6 AA NiMH battery for 7.2 volts for external power pack. 2 multi-meters on for milli-amps and second monitoring voltageTXPower set to 20 clean start.TXPower set to 100Video recordedEken pulls about 400-500 mAh during start-up. Normal web surfing I range 650 to 750 mAh, peaking around 850mAh (milli-amp-hours). I turned on Pandora and at full volume, wifi streaming data 1200 mAh200mAh difference if I reduce brightness down to 25-33%200mAh difference if I turn off wifi000mAh difference for 20 to 100 wireless TXPower hack (zero)I recorded video, but surpassed the 15 min limit. I'll work on splitting the two videos, one has 20 TXPower other 100 TXPower. Both have meter recording amps being pulled from battery. Even opened 6 browsers with swap turned on and switched between browsers. For estimating purposes, wifi surfing 900 mAh (no audio)Strange behavior noted, Benchmark program by Softweg had no difference in power usage. CPU, video, memory, system, no difference. Desktop PC benchmarks pull hundred of watts extra (watts= amps x voltage) {P=IxE}. So setting throttle on Eken will improve battery life. Sorry, wifi hack = NADA :confused:100% brightness 713 mAh
25% brightness 559 mAh
 

·
Registered
Joined
·
255 Posts
Thanks heaps for going to the trouble of measuring this and posting it, tron. I have a few follow-up questions, though.
.When you say "mAh" for measurements do you actually just mean "mA" (ie the reading taken directly from the multimeter?)Did your NiMh battery pack voltage drop at all under load, or did it stay around 7.2v? Did you have the battery pack plugged into the DC input socket on the tablet case, or directly into the battery pack socket on the board?Did you measure the idle power consumption for both TXPower 20 & 100 (but before the screen dimmed or anything else changed)?I'm not surprised that the WM8505 doesn't do much active power management, especially on the current kernel. I think there's quite a bit of potential there.I have to say the overall consumption figures seem pretty good though - if those are mA values then that means <6W surfing the web, peaking at 9W.
 

·
Registered
Joined
·
187 Posts
Discussion Starter · #4 ·
[quote name='projectgus;43965]Thanks heaps for going to the trouble of measuring this and posting it' date=' tron. I have a few follow-up questions, though. [IMG]http://www.slatedroid.com/public/style_emoticons/<#EMO_DIR#>/smiley.gif[/IMG].When you say "mAh" for measurements do you actually just mean "mA" (ie the reading taken directly from the multimeter?)Did your NiMh battery pack voltage drop at all under load, or did it stay around 7.2v? Did you have the battery pack plugged into the DC input socket on the tablet case, or directly into the battery pack socket on the board?Did you measure the idle power consumption for both TXPower 20 & 100 (but before the screen dimmed or anything else changed)?I'm not surprised that the WM8505 doesn't do much active power management, especially on the current kernel. I think there's quite a bit of potential there.I have to say the overall consumption figures seem pretty good though - if those are mA values then that means <6W surfing the web, peaking at 9W.[/QUOTE']Your correct, I should use mA (milliamps) as its being measured by my multimeter. I averaged .4 to .5 volt drop from my NiMH external pack. Two of the batteries weren't freshly charged and all are over 2 years old. I had it plugged in to the external connection.Amperage usage varied so much I was only able to estimate a range when testing TXPower of 20 and 100. Idle with no wifi activity and then I pulled up webpages to make sure wifi was running. I'll work on splitting the videos. Both 20 and 100 TXPower videos are over the 15 min Youtube limit. So there could be a difference between 20 and 100, but as you'll notice in the video its not evident at all. Dropping brightness down or turning off wifi is a noticable power usage (mA) difference. I'm interested in knowing what is suppose to be effected my changing that value. My USB wireless mouse now crashes my system when I plug it in but not wired USB. Also I can't play any audio from SD, and picture viewer doesn't work. All that could be related to Caffeine ROM or just bad install.I set my system to dim after 10 minutes, or never and do it manually. When testing dim, I did it manually.I can get my Eken to start to boot with 6 volt battery, but never completes boot process. I think if I can stay above 6 volts (minimize voltage drop) I might be able to boot and run from a 6 volt battery pack. I have a few 4.5 Ah sealed lead acid batteries I'd like to put to use. Backpack powerpacks.
 

·
Registered
Joined
·
187 Posts
Discussion Starter · #5 ·
Hard to tell if 7.2 volts is charging the internal battery or not, it draws 400ma sometimes, other times it starts at 350ma and starts to slowly go down, and sometimes I'll plug it in and 0ma being pulled. It should take 9v to charge. I left the 7.2v pack plugged in for 30 min and tried to boot device, it only flickered. Plug in battery pack and started right up. Should not charge with 7.2 volt power source plugged in. More testing to prove. Also almost got it to boot on 6 volts. Can conclude, no benefit to wifi TXPower 20 vs 100 change.
 

·
Registered
Joined
·
255 Posts
[quote name='tron33;44325]Hard to tell if 7.2 volts is charging the internal battery or not' date=' it draws 400ma sometimes, other times it starts at 350ma and starts to slowly go down, and sometimes I'll plug it in and 0ma being pulled. It should take 9v to charge.[/QUOTE'] If you're providing 7.2v to the external input then you're powering at least two extra circuits (probably combined in one) - the voltage regulation to get the working voltage (7.2v or less) for the tablet, and the battery charging circuit. As you say, it may not be working properly because you're not providing enough voltage but it's probably still consuming more power than would be drawn from the battery itself.If you really want to power it from 6v SLAs then you could always try to break out the battery connection to an external port. Not sure if you'd need to manually switch out the LiPO cell or not.My M001 has the case off it more or less all the time, so if I'm feeling adventurous I'll wire in my meter and see if I can measure the current drawn directly from the battery.
 

·
Registered
Joined
·
187 Posts
Discussion Starter · #7 ·
Played around with a 6V 4.5mA lead acid battery. Charged it sat at 6.5 volts, but once plugged into the Eken it dropped to 6v but I was able to boot up, connect bluetooth, use BT keyboard/mouse and surf the web. Once it dropped to 5.85 volts the system powered down. So EKEN M003 will boot and run of a solid 6 volts power source AND no sync required to get Logitech Bluetooth keyboard and mouse to work, just plugged the Logitech BT dongle and everything worked. My other BT didn't work with KB/M just the Logitech brand one, for the Logitech Keyboard and mouse. Anyone want to see the video? Shows battery voltage meter reading, you'll see BT start to just work..
 

·
Registered
Joined
·
255 Posts
[quote name='tron33;45387]Played around with a 6V 4.5mA lead acid battery. Charged it sat at 6.5 volts' date=' but once plugged into the Eken it dropped to 6v but I was able to boot up, connect bluetooth, use BT keyboard/mouse and surf the web. Once it dropped to 5.85 volts the system powered down.[/QUOTE']Nice!
I'm guessing the system itself may be running on a regulated 5v then.[quote name='tron33;45387]no sync required to get Logitech Bluetooth keyboard and mouse to work' date=' just plugged the Logitech BT dongle and everything worked.[/QUOTE']Most wireless keyboards/mice with their matching dongles will emulate USB HID endpoints (ie USB keyboard & mouse) for their particular devices, until the computer requests them to switch into HCI mode (ie become a proper bluetooth dongle.) This is good for installing OSes, accessing the BIOS, etc. So I'm guessing that's probably what you're seeing - there's no bluetooth stack running, but you can use your peripherals.
.
 
1 - 8 of 8 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top