Measured power usage of various items and est'd impact on range

[Hi-Voltage]

The heated seats use 15W, 30W and 45W (on high) supposedly.... big difference versus running the actual heater...

MrEnergyCzar

In other words I will have to limit my wife 's driving in the cold weather or she is gonna kill my stats

BTW thanks for all those numbers and work

[briveland]

This was actually on my list of things to test next, but, I need to automate my software bit more for safety, or draft my girlfriend as button pressing monkey...

hmm... not sure I would would lt her see this post!

[wizkid057]

yeah I knew about the monitor one.. I wanted to figure if the masks would let you monitor many. Doe the rasbury keep up with the OBD in MA mode?

It seems to do fine with the MA, but the ELM327 device I have has some issues occasionally with data errors and such. I've peaked the RaspberryPi at about 8 megabit through a USB ethernet adapter, so, 500kbps should be fine for it.

hmm... not sure I would would lt her see this post!

Too late! :P

[VeridianJoule]

Does it make a difference which battery the specific accessory is powered by to get accurate calculations or is the system all working together? I'm guessing there is no traditional alternator that re-charges the 12 volt battery in our Volts is there?

[saghost]

Does it make a difference which battery the specific accessory is powered by to get accurate calculations or is the system all working together? I'm guessing there is no traditional alternator that re-charges the 12 volt battery in our Volts is there?

Items on the 12V bus are powered through the APM when the car is on - a DC-DC converter that can pull up to 2kW from the main battery. In theory, you lose a little precision from the presence of the 12V battery and the efficiency of the APM; in practice the numbers we're working with aren't that precise to begin with.

[RScott]

I think one of your posts said you were dropping data on the Bluetooth ELM327 devices. Are they BT 1.1 (1 Mbps) or 2.0 (3 Mbps)?

http://en.wikipedia.org/wiki/List_of..._area_networks

From what I have heard, the Bluetooth adapters are too slow to keep up with the Volt's 500kbps. The ELM327 isn't fast enough to capture all the packets all the time, either, but at least gets most of the data (enough to be useful). I haven't tried a Bluetooth adapter to see what kind of rates it really gets.

Part of the issue is that the 500kbps is raw data, whereas it gets converted to ASCII, so you need more than a 500kbps connection to be able to read the data (unless the adapter sends it in its raw form).

[PatsVolt]

Climate Power, relates more to total BTU capacity rather then the raw electrical power and is an estimate of percentage of BTU's needed to keep the cabin at what ever temp is selected. A good examlple of how Climate Power numbers can change for a given setting is when in Very cold weather, when below 27 degrees the ICE will start, in this process as the engine heats and begins to cotribute to heating the cabin, you will see the Climate Power drop because the engine can produce a very large number of BTU's. thus the 100 % point gets readjusted upward and the since the cabin does not demand more Climate Power then the Climate Power number decreases. When the Ice turns off you will see the number increase. You may also see this in CS mode in the winter if the ICE turns off periodicly.

Pat

[wizkid057]

From what I have heard, the Bluetooth adapters are too slow to keep up with the Volt's 500kbps. The ELM327 isn't fast enough to capture all the packets all the time, either, but at least gets most of the data (enough to be useful). I haven't tried a Bluetooth adapter to see what kind of rates it really gets.

Part of the issue is that the 500kbps is raw data, whereas it gets converted to ASCII, so you need more than a 500kbps connection to be able to read the data (unless the adapter sends it in its raw form).

Exactly. The issue is that the ELM protocol sends the data in ASCII based hexidecimal, so, 500kbps of binary CAN data ends up being well over 1 megabit, probably closer to 1.5 megabit. If you really really REALLY wanted to make something like this work over Bluetooth PAN or similar, you'd have to compress the data on the fly on the sending side and decompress on the receiving side. Not really worth it IMO.

-wk

[Fulgerite]

This is a really an excellent and informative post. (Thank you wizkid.) I did some tests of the fan blower current consumption which I measured by removing the fan fuse and measuring across it with a digital amp meter. (VOM) I got about 20-21 amps with the fan at full speed... (Which I think is pretty close to what you calculated... Within a few watts.)

[wizkid057]

This is a really an excellent and informative post. (Thank you wizkid.) I did some tests of the fan blower current consumption which I measured by removing the fan fuse and measuring across it with a digital amp meter. (VOM) I got about 20-21 amps with the fan at full speed... (Which I think is pretty close to what you calculated... Within a few watts.)

Yeah, I had actually done some similar tests for some 12V accessories and it turns out the for anything over 25 watts or so measuring the APM's draw on the HV battery is pretty accurate. And, as it turns out, the APM is insanely efficient (> 90%).

Current draw/gain on the actual 12V battery appears to be near non-existent regardless of what accessories are powered while the vehicle is powered on, once the 12V battery is fully charged after a power up. So, the 12V battery should have little effect on any readings. This also seems to thwart my idea of adding a minimal amount of range by adding supplemental 12V power to offset accessory power usage...

-wk