Daox's 2004 Toyota Prius Build Thread

[bwilson4web]

Originally Posted by Daox

. . .
Anyway, I finished up the temperature hack shield this morning. I did make a small change to the schematic. To reduce the amount of resistors needed I put just one 560 ohm resistor before all of the resistors.
. . .

I would expect the LED intensity to be a function of how many LEDs are on at one time. The original circuit would keep the LED currents identical for any combination. However, if only one LED is expected to be at a time, it is a good hack.

BTW, one thing I did with my hack was to have the LED blink in proportion to different diagnostic modes.

GOOD LUCK!
Bob Wilson

[Daox]

Yeah, the LEDs only light up one at a time. The green shows the coolant is too cold to fake the signal. Yellow is faking the signal. Red is coolant is hot enough to not need faking.

[Daox]

I've now hit half a tank of gas with using the PHEV for nearly the whole time (had one or two trips beyond the kit's range). Last fill up was 9/4 and its 9/14 today. I've been averaging around 100 mpg on the way in to work and in the mid 70s on the way home. Every once in a while the wife takes the car and that drops things down a bit. The tank is currently at 75 MPG according to the onboard MFD and slowly climbing.

As I was commuting to work this morning it was about 45F out. My commute is 7 miles long. First I have a short jaunt in town (in EVv mode) to a 45 mph county road (hybrid mode) then back to a short jaunt in town (mostly all electric) to my workplace. Today I noticed that getting to the town my workplace is in, my coolant wasn't even up to 155F yet (this is necessary to engine off consistently in the Prius). So, this fall and winter heating will definitely be a huge deal for me. Once it gets down to around freezing (37F I think), EV mode won't be even be available. The Prius simply doesn't let you hammer the batteries when its that cold out. So, I'm going to have to start blocking more of the grill (upper grill isn't blocked at all ATM), and using the block heater pretty soon.

I've had some issues with the coolant hack and it is currently not working. It will be a necessity with the PHEV to get as much engine off as I can.

[Clev]

Does it go by engine temperature or battery temperature? Maybe you could put a "block heater" (ceramic electric heater) in the battery compartment and preheat the batteries a bit?

[Daox]

I'm sure it does go off pack temperature. A heater is always an option.

[Daox]

Speaking of heaters though. I did just pickup a spare prius coolant thermos from the junkyard the other day. I was there hunting down a headlight leveling sensor since mine went bad and saw the shiny tank just dangling there. I decided to pull it and bring it home. I'm not sure what I'm going to do with it yet, but I couldn't pass it up.

The first thing I've beent thinking is that I've always wanted to add a heater to the coolant thermos. It makes sense to me, warm up the insulated tank to dump hot coolant into the engine vs warming up the engine block and coolant and then pumping the warm coolant from the thermos into the warm engine and the warm coolant from the engine into the thermos. I'll be looking into this.

[Clev]

If nothing else, can you string two of them together to double the capacity?

[MetroMPG]

Originally Posted by Daox

I did just pickup a spare prius coolant thermos ... I'm not sure what I'm going to do with it yet ...

Soon you'll have the neatest coffee thermos in the office!

[Daox]

Originally Posted by Clev

If nothing else, can you string two of them together to double the capacity?

I'm not sure about that. I do know I'd have a hard time trying to find room for two of them under the hood.

Edit: Upon further thinking I don't think this would work good if they were in parallel. They are roughly equivalent to the volume of the engine. So, if the engine dumps into them it would only half fill each of them. If we put them in series, you'd just be dumping cooler coolant into the engine each time the thermos' dump their coolant.

[Daox]

Just finished the first full tank with the PHEV kit used. There were a few trips that were beyond its limits. Also, there was a learning curve on how to best use it. So, I hope the next tank is a little better, but its still not bad.

504.8 miles
6.39 gallons
45.12 kWh
65.3 MPGe (using this as my fuel log entry)
79.0 MPG (doesn't account for electricity used, just gasoline)