As an automotive instructor for my local college we have been facing up to the fact that for quite some time we have been behind the curve. We knew we needed to implement hybrid and electric vehicle training into our program, but as any old gear head would do, we shied away from learning about those “green cars” because of all the stereotypical reasons. However, something in me changed the second I took a hybrid course in Massachusetts: Hybrids were broken, they were failing and best of all, they were cheap. I was hooked.
My Search For a Hybrid Car
As soon as we touched down back in our home state, my search for a hybrid car became a top priority. I quickly found a broken 2006 Honda Civic Hybrid that “wouldn’t go anymore” and had what presumably was a bad CVT transmission. Perfect, I had connections with a local junk yard and this seemed like a great place to begin my own research on hybrid vehicles. We tore into the Civic and after doing quite a bit of research we discovered that Civic had two fatal flaws between first and second generation.
Gen 1 Civics usually succumbed to start clutch failure a $500 dollar fix, and Gen 2 usually succumbed to either breaking a CV shaft or losing the dual mass fly wheel, a much less expensive fix but also one that for sure would cripple it. We had a stripped dual mass, and found a good used one for $100. After some CVT fluid and a couple seals we were back on the road. I was in love, or so I thought. My heart and soul was aching for something, and at the time I couldn’t figure it out. Time would prove to me that I was being groomed for something better to come.
I drove that one and even bought a first gen Civic Hybrid with a bad battery that I quickly fixed and resold after learning about the software issues that plagued the 1st Gen Civics (Read: Civic Hybrid vs Prius a matter of style and brand loyalty). This also led me down another rabbit hole of the differences in cells vs modules vs packs and what parts are what. It was a great learning experience but I just was not satisfied with what I was doing. It was then I knew I wanted a Toyota Prius.
My Search for Toyota Prius
I was attending a seminar over in Seattle that next month and had signed up to take a “making hybrids profitable” course by a guy who claimed he had figured out how to repair aging or failed HV battery packs. I beamed with excitement and found the class incredibly helpful as I learned some really cool things about Ni-MH (nickel metal hydride) that I never knew before.
I began the search for a Toyota Prius as soon as class let out. Little did I know at the time how the owners of these things were so attached to them. It took some time but I managed to find one with a bad HV battery. The crazy cat lady ( as I call her) and I negotiated the terms and I was able to drive home MOMOZ Red Wagon, a 2007 Touring Edition 2nd Gen Prius, with 245,000 miles for $1000.
Learning About Toyota Prius
This is where my real education began. The 12v battery (which is a common culprit) was dead, go figure so we jumped it, and I was quickly on my way to Prius ownership. I was thinking of all the good times I could have with the great fuel economy, and everything else that accompanied this strange little wagon. I dove in head first.
Of course the priority was the HV battery. After taking the course on battery reconditioning, I now knew that I could potentially save that battery pack. I made an investment and in a week had my materials. The charger, discharger and harness that needed to be wired into the battery. I read through the details and user guide and set to work. This is where I learned about Delta SOC or state of charge. Using the scan tool I had available to me, I found that my Delta SOC was over 50%. Researching this told me that Delta is accounting for the usable capacity that the battery has and the higher the Delta, the less energy you can actually store inside the battery. A true sign of pack failure.
On this journey as well I began learning about all sorts of battery types, nickel metal, lithium ion, and others including solid state batteries. I even learned about nickel cadmium and nickel iron batteries as well due to the fact they were in the same family as nickel metal hydride. Very fascinating. I found that a common issue with the family is that the inherent “memory” effect is what actually takes down these batteries, which after inventing Ni-MH this was supposed to be cured. It wasn’t. These batteries are great and can take the abuse that we dish out but over time they develop Alzheimer's and lose their ability to fully use the available space in the battery. This was magic to my ears.
I quickly began connecting the dots. I realized that the tools I had purchased were like a backhoe and the battery was like a ditch filled with mud. All we had to do was scoop out the mud and restore what was lost. But it didn't work the first time.
The battery modules ( which in Toyota vehicles ) are the bar style batteries (not the round ones you find in Honda) can diminish to the point where they no longer function at all, regardless of reconditioning. I had to tear into the pack. I wanted this to be an affordable cheap daily driver for me and so I was hell bent on doing that. I found locally a HV battery out of a 2008 Toyota Camry that had recently been wrecked and had only 140K on the clock. I had no clue at the time, but I was willing to risk the $150 bucks it took to get the battery to see of the modules were the same. That roll of the dice saved me. All the modules I came to find out were exactly the same and now, I had more of them.
I also learned that Tahoe had a similar battery pack with the same modules as well. Open the flood gates of repairs because I was seriously excited about it now.
I fixed the Prius Battery
Long story short, I fixed the pack, learned how to nickel plate my own bus bars and fix this hybrid. I am into it dirt cheap and i get over 40mpg average. This is where my idea about how people look at these cars changed. I have a super reliable less than $2000 fuel sipping red wagon that costs almost nothing to operate. the best part was that it was easy. Anyone with a weekend and a few tools, (lets not forget common sense, we are dealing with high voltage here) can do this. That is the beauty of how well engineered these cars are (Also Read: Don't Buy A New Toyota Prius Hybrid Battery - Have It Repaired Instead).
My point is this, if you want to think hold onto your stigma of how Prius is whatever you want to think it is, go for it. But for me and my super affordable fuel saving red wagon of awesome, we are busy ripping up the country side enjoying life.
Make A Toyota Prius Hybrid Battery Last Past 350,000 Miles Performing Your Own Replacement and Click to Subscribe to Torque News Youtube Channel for Daily EV and Automotive Analysis.
Don't Miss: How To Make A Toyota Prius Hybrid Battery Last Past 350,000 Miles. See you in the next story where I am discussing 2 updates 2007-2009 Toyota Prius owners can and probably should make.
Peter Neilson is automotive consultant specializing in electric cars and hybrid battery technologies. He is an automotive technology instructor at Columbia Basin College. He holds a Bachelor of Science in Automotive Service Technology from Weber State University. Peter can be reache on Linkedin and at Certified Consulting.