Make XP think it's running on batteries?

**malcom2073** · 11-21-2009, 02:45 PM

Originally Posted by justchat_1

Exactly!!

I looked into this awhile ago and I think the problem I had was that windows only can use one ACPI HAL at a time....so you would need to create a replacement for the one currently used with your BIOS.

I don't believe that's quite the way to do it, you want to write a new driver using the ddk, then you register it as a battery driver using CreateService. This driver then tells the OS "you have a battery installed" and the os believes it. No ACPI, no bios settings required.

**2k1Toaster** · 11-21-2009, 02:53 PM

Would it not be much easier to just plug in hardware to monitor the voltage level and run in the system tray and relay back and forth through the native windows API calls to whatever ACPI layer is running? So the program looks like the battery monitor (which wont be there in a desktop install anyways, so a duplicate isnt an issue), but is a custom program emulating it.

Seems trivial. Hardest part would be characterizing your SLA over my SLA over ayone else's. A lithium battery is a bit more predictive in charge over a range then the cars. But it could be done.

**justchat_1** · 11-21-2009, 03:00 PM

I thought acpi would give power info that would prevent windows from acknowledging the battery driver. I dug into it and your right, power states are reported but nothing that would indicate battery vs. ac power

**rickhigginshtbr** · 11-21-2009, 06:36 PM

....why don't you just get a voltage gauge?

**justchat_1** · 11-21-2009, 06:44 PM

Originally Posted by rickhigginshtbr

....why don't you just get a voltage gauge?

Cause it would look very out of place in cleaner installs

**rickhigginshtbr** · 11-21-2009, 06:49 PM

Originally Posted by justchat_1

Cause it would look very out of place in cleaner installs

depending on the car, yes, but not in most cases. Plus, it could be put in a hidden area as well.

**malcom2073** · 11-21-2009, 08:06 PM

Originally Posted by rickhigginshtbr

depending on the car, yes, but not in most cases. Plus, it could be put in a hidden area as well.

C'mon man... this is mp3car. The entire purpose of this website is to over-engineer a simple problem to provide an outrageously complicated but nonetheless elegant solution

**trader007** · 11-21-2009, 09:39 PM

Originally Posted by malcom2073

C'mon man... this is mp3car. The entire purpose of this website is to over-engineer a simple problem to provide an outrageously complicated but nonetheless elegant solution

far from it. i wouldnt have a carpc if it didnt make driving easier. reliability and convenience are key, and if i wanted a battery meter i would replace my analog one in my dash with a digital...

i mean to put a meter inside windows just to do it is fine, however it will make zero difference to how you use your pc, and the for the trouble it will be i just wonder where the motivation comes from.

**justchat_1** · 11-21-2009, 09:55 PM

Well it depends on how you use your PC... you could have a system that remains active with the car off until a certain battery level (so you can listen to music while at the gas station) and then automatically shutdown. You could also use the PC to give you ETA, so you know its safe to play music for the next X minutes and will still be able to start your car (unless you think watching the gauge and trying to figure out rate of discharge is more convenient).

Is it easy to do? Depends if you want it at the OS level or the FE level...Worth it? Depends on your use...but zero difference? idts

**trader007** · 11-21-2009, 10:18 PM

Originally Posted by justchat_1

Well it depends on how you use your PC... you could have a system that remains active with the car off until a certain battery level (so you can listen to music while at the gas station) and then automatically shutdown. You could also use the PC to give you ETA, so you know its safe to play music for the next X minutes and will still be able to start your car (unless you think watching the gauge and trying to figure out rate of discharge is more convenient).

all that can be done with a simple shutdown controller, and it will be 100% automatic.. and 99.9% failsafe. putting a battery meter inside windows and trying to do all these things you want based off that just doesnt make sense when there are cheap hardware solutions that plug n play without hassles.

i know op said 'just because', and thats fine. i just think there are so much better things you can do with that time itll take to pull off, so much cooler things....