Thread: Make XP think it's running on batteries?

For the PC software, I believe the most elegant solution here would be leverage the existing UPS and Battery monitoring code on XP. This code will report on battery vs main, and also initiate shutdown in the event of a low battery condition.

As for hardware, if we think of the car in terms of a giant UPS, collect this information, and then provide it to the PC via USB with a standard UPS HID format, we get most of this for free.

I would think of the system as follows: (Remember this is an abstraction)
Car Battery = UPS Battery
Car Alternator = Battery Charger,Utility Power
DC-DC Power Supply = UPS Inverter

We could than make a board that provides the following functions
#0 - Car Start
#1 - Measure Battery Voltage
#2 - If battery voltage is at a safe level(preset by the user), turn on the inverter (Power Supply)
#3 - If Battery Voltage is less then a preset value (13.0?) for a small amount of time then the System is "On Battery" otherwise it is "On Utility".
#4 - If "On Battery" measure battery drain current (Note: You could also do this step instead of #2 and consider "On Battery" if a positive current drain, and "On Main" if a negative current drain.
#5 - Using a look-up table specific to your car's battery, calculate battery charge state and battery time remaining.
#6 - If the battery time remaining value from step #4 is below a set value, then report a "Low Battery" condition.
#7 - Make all this information available to XP via USB in a format that makes XP believe it is connected to a UPS.
#8 - If the Battery time remaining has expired, then shut off the inverter (Hopefully XP has shutdown before this point).
This could be a starting point, it would also need to work with the PC power supply to prevent conflicts in overlapping functionality.

malcom2073 has the right idea. A miniclass driver would be required for simulating a battery service in Windows with no HAL I/O, but rather interface it with Fusion Brain or some other hardware.

But like a lot of people I don't see the point. Just having something that can read the battery can also display it even better embedded in a frontend. The only reason for the GUI to display percentage or voltage is because a laptop battery driver or UPS driver is the only way to display it. A car has a volt meter at least when the ignition is on, or can have an aftermarket meter, and a car PC has an intelligent PSU.

Originally Posted by justchat_1

But an intelligent PSU doesn't give you a countdown till it shuts down.... It can't decide that since your playing music don't shutdown until low battery or since your just at the main page hibernate immediately... It can't be combined with OBDII info to tell you that a charging system malfunction is a bad alternator not a dieing battery....It gives you dozens of scripting options....

why limit everything to the same old carpc basics?

i designed a simple shutdown controller that does just that. once the battery gets to a certain level you choose, a warning light starts flashing and then i know i have just a few minutes before hibernation starts.

as far as 'estimating' how much battey life you have left like in a laptop, i still dont see the point. most of our pc's wont run for more then an hour before our batteries are too weak to start the car, so if you know you only have a good half hour to begin with there isnt much need for a ETA. just fire up the pc and use it for what you need, if you run over itll give you a warning and then hibernate.

dont forget, windows screws up a lot too. to design a low-power shutoff script and run all that in windows you would be relying on software to do a somewhat critical function (not the best idea).

Good point. A PC can (and will) hang on shutdown. A laptop, real UPS and car PSU can cut the power and save you a battery and possibly a tow to get a new battery.

Using FB, OBD-II or even the serial input type hack you can detirmine when the engine is off and check volts (FB/OBD) and assuming you know the draw and battery condition/capacity, start an alert timer, voltage display, show battery level and all that while still allowing the PSU to cut power.

I think the PSUs can do that? I have my own SDC as well, but redesigning it right now to work with a new DC-DC USB thing to do all kinds of strange stuff.

its actually happened quite a few times to me already. its good to know though, that in a frozen state my pc doesnt draw that much... because after the m2 hard shuts off after 2 hours my truck still starts fine.

here is basically a cheap hardware solution for all that smart stuff you guys are talking about. maybe you can use it to feed data into windows to get your built-in support you want... redundancy is never a bad thing in cars. http://www.amazon.com/Argus-BB-SBM12...9036043&sr=8-1

Oh heck, just get a fusion brain and remote start add-on module. When the voltage reaches about 12.1V, send a pulse to the starter, let it run for 5 minutes, then pulse the brake input or whatever stops it. LOL