All done

Now have a 2013 Volt that I am VERY happy with, a car better engineered to do what I was expecting the Prius conversion to do.

The Prius did well for just over 2 years, then developed problems with the BMS/control boards/and cells that were not fixed by those supporting the conversion.

Will put this to sleep soon and probably replace with a Volt blog.




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getting better at this…

110 mpg (scangaugeII) on the commute today.

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Pure EV range = 48.7 miles

Today, did my first test run in pure EV mode (ICE-kill). Temps were 75-85F, no AC, stereo blasting. I was on rural roads, estimated average speed was around 38mi. Probably less than 10mi at the maximum (52mph). One 10 min stop otherwise, continuous driving. Terrain mostly flat, slight occasional hills. I ended the test when I noted “blue bars” on the monitor, It has been my experience that this is the time to pull over and reset. Total mileage for a full charge was 48.7!

Otherwise the car has been operating flawlessly, my true mileage (measured at the gas tank) for the last 2000mi is 69.6 mpg….It should be noted that I am not a hyper-miler, that my usual commute involves some hill-climbing, and is mostly at 60mph.

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Plug-in Prius

2009 Prius Conversion  – A Berkeley, CA company, 3ProngPower, Inc.  (, converted my standard 2009 Prius into a PHEV (plug-in hybrid electric vehicle). You might note that the rear-end is sitting higher as a result of the suspension upgrade to accommodate the extra 300 lbs of lithium cells, adding a rechargeable powersupply of 10KWh. The manufacturing company, Plug-In Supply has been VERY accommodating with upgrades and fine-tuning.

The lithium cells fit into a steel enclosure that fits in the rear compartment under the storage panel over what was once access to the mini-spare tire. The charger unit is on the right with 110 plug on the bumper.

The lithium cells are individually monitored and managed by an Elithion (  Battery Management System (BMS).

Here’s a picture of consumption for a combination of city and freeway driving. Sixty-eight miles at 99.9 mpg.

Finally had time today to do a meaningful comparison of my Prius’ mileage before and after the 10KWh conversion. I wanted to see how far I could use the conversion before the big battery (green bars begin to drop to blue) was no longer aiding the ride. This was just over 100mi, over my usual commute (90% highway) with the PHEV switch engaged the whole time, only briefly in pure EV mode (<32mph), over a hilly course that my prior mileage was 44mpg….My mileage was 76.3 over the 100mi course.

I will be doing gas-consumption testing as I have time over the next few tanks.

I have yet to test the fully charged battery in “ICE-kill” mode (pure EV with 52mph limit), just need to become more comfortable with the changes before I try it.

Plug-in Prius with solar & wind power

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