I had started a discussion over in the Camry section about how to add more battery capacity, and how you surmount the obsticles in the way.

See:

http://www.greenhybrid.com/discuss/s...ad.php?t=11885

As a result of some of that discussion I PM'd one of our local technical experts Bob Wilson to get his take on it, and he sugessted first starting with some instrumentation to learn more about the operation of the car.

At his prompting, I am reposting some of his PM to me so we can start a discussion in the public to get more information out to a wider audience.

Quote from PM:

Quote:
Originally Posted by ag4ever
Quote:
Originally Posted by bwilson4web
I understand in the Prius plug-in community, they have to 'hack' a battery controller interface so the additional capacity can be used. When the battery state of charge (SOC) apparently determines the charge/discharge characteristics. Trying to dump the power on the bus between transaxle and battery pack assembly doesn't work either because the controllers detect the mismatched current and throws an error code. It is a hard problem.


That is what I was thinking, but I was not sure of that. I was kinda hoping they were just hacking the programing and reconfiguring it like the "power programers" do for gas and diesel engines.



Quote:
Originally Posted by bwilson4web
Let me suggest starting with instrumentation, to understand what is going on. Then look at modifications.

So where should I start with instrumentation? I guess the very basic would be to get a scan gauge, but I am sure that would only provide me with basic data, and I am sure I would be more interested in more detailed data that could be collected by a computer to be analized latter.

Let's take this to a public forum since others would be interested too.

Bob Wilson

So what is everybody doing for data collection on the TSD or HSD systems?

What data are you collecting?

As a basic start I want to know how much fuel is being burned, how much energy is being taken from or given to the battery, and how those data sets correlate to speed, rate of acceleration/decelleration, state of charge, engine speed, MG1 and MG2 speed. All data should be logged against a common time stamp.

Thanks!!!

Before I got my Graham scanner, I was building my own instrumentation for my Prius. These techniques are universal and work on any hybrid vehicle so I would like to share them. Some of our Japanese friends have followed a similar path with the NHW20 models, building their own instrumentation. Finally, good friend Hobbit of the Prius_Technical_Stuff YahooGroup has done similar work.

What we all did is start with the electrical schematics from the maintenance manuals. Without the schematics, many interesting signals will be terribly hard to hunt down. Then comes the easy part, measuring them.

Hobbit uses small jumpers to critical signals that he routes to the passenger seat oscilloscope or breadboards. Typically he records the data manually and is done. Our Japanese friends, do one better with instrumentation connected to uprocessors. This leads to some of the 'super scanner' devices. My approach is to use the stereo audio channels of a laptop to record the data for later analysis:


What you see is a miniature audio jack connected to some ethernet cable that goes to a pair of magnetic line coils. Earlier testing verified that 50 turns would generate a 1 V. peak-to-peak signal, exactly the right level for 'line input' to the laptop microphone jack. The pipe clamp, carriage bolt and wing nut are used to clamp around one of the MG power leads with the carriage bolt going through the magnetic pickup coil. With two pickup coils, one goes around an MG1 lead and the other around an MG2 lead. This allows recording the power going into or out of MG1 and MG2 as an audio recording:

http://hiwaay.net/~bzwilson/prius/magnetic.html

This gives you a way to see the current signals and begin to understand vehicle operation. The same technique can be used to monitor fuel injector timing and other AC signals. For DC voltages, you'll need a 'chopper' circuit and suitable voltage divider networks.

Once you have data, you can look at timing relationships and even calibrate the signal using a 120 W. light bulb and a single wire through the pipe hanger. Fairly simple programs can convert the audio data into spreadsheet compatible format. But the biggest gain is seeing what is happening:

http://hiwaay.net/~bzwilson/prius/motor.html

My last suggestion is to install an ethernet cable between the engine and the cabin to bring interesting signals inside. My approach is to find the 'fresh air' vent, remove the cabin air filter and drop the cable down, out the cabin filter holder:

Then I drilled a small whole in the filter frame, threaded the cable and voila, I have ethernet cabling between the cabin and engine compartment:


http://hiwaay.net/~bzwilson/prius/pri_tt.html

Obviously these techniques need to be adapted to your specific vehicle but the nice thing is:

1. Independent of OBD scanners
2. "Real-time" data versus lags found in OBD data
3. Subtle effects not visible in 'just a number'

The bad thing is you'll need some skills and resources:

1. laptop with audio input jack and 'open source' (free) audio software
2. understanding of basic electronics
3. self-calibration of test circuits
4. software if planning to convert to excel analysis format

Does this help?

Bob Wilson

Operation Iraqi Oil Freedom:

Automatic, stock, project car.

My other 1500 cc car:

Automatic, stock, backup car.
Free speech, dialog and knowledge thrives without the poison of SPAM.

That helps considerably.

I have an old laptop that I might pirate into a car computer, and start getting some basic readings.

I think I might talk some of this over with my father. He is an electrical engineer who has spent most of his life working on non-destructive testing equipment for the oil and gas industry. A lot of this instrumentation would be second nature to him, and since he is a couple years away from retirement, I might be able to get him interested in this.

But then again, he has taken a big interest in video editing, so I will have to fight for time.

We have super enthusiasts named Graham Davies, decoding OBD-II messages on NHW-11 Prius, and Attila Vass, decoding CAN messages on NHW-20 Prius.
I've never heard any on Camry Hybrid community.

Ken@Japan