New owner of an old Prius

Hello to everyone!
Yes, I am another guy who recently purchased a high mileage Gen2 with a bad battery.
I have been a mechanic for many years but have had relatively little experience with fixing hybrid problems. I
see fairly few hybrid cars in my area- maybe 15 different Toyotas, a few Fords and Hondas. Usually they
come in for routine service- oil change, brakes, tires, A/C, etc. Nothing about the electric drive systems.
So when a chance came up to buy a 2006 Prius with 160K and a RTOD (P3000/P0A80) for $500, I jumped
on it.The exterior was fairly clean, but the under chassis is a bit crusty-rusty. Engine runs nice and inspection
monitors are OK, A/C blows cold. No other serious codes in any system. Needs a HV battery and some other
"minor" work. Pretty much the nicest cheap car I've seen. It has option HK (window option sticker was in with the owner's manual). So SKS, HID headlights, VSC, etc

First thing is the battery. Scan data showed block 9 to be 1.2V lower than the others. My options are: New,
used, rebuilt, or DIY. I could get a Toyota battery for around 1800, but not now. I wanted to get the car
running somewhat before that kind of investment. Besides, buy new parts everywhere and soon I would have
over $4k in a cheap car that I don't really NEED. I had already heard bad things about Dorman and
Greenbean units so no rebuilds. A used battery MIGHT be good, MIGHT be bad- nobody knows. So I went DIY. I figured that if it worked, then great. If it didn't work, then oh well. Either way I would learn something.

First thing is the battery. Scan data showed block 9 to be 1.2V lower than the others. My options are: New,
used, rebuilt, or DIY. I could get a Toyota battery for around 1800, but not now. I wanted to get the car running somewhat before that kind of investment. Besides, buy new parts everywhere and soon I would have over $4k in a cheap car that I don't really NEED. I had already heard bad things about Dorman and Greenbean "rebuilt" units so no. A used battery MIGHT be good, MIGHT be bad- nobody knows. So I went DIY. I
figured that if it worked, then great. If it didn't work, then oh well. Either way I would learn something.

Searching the web for DIY battery repairs led me to PRIUSchat. Yes I read the entire battery module
replacement thread. Bought 2 cheap chargers. Learned just how slow 5W discharge is. Bought 2 slightly
better chargers, then a 200W discharger and replaced 4 modules (ebay- listed as 5-6Ahr). Spent over a
month of spare time cycling modules- all measure 5500 to 6200 mAhr. Put it back in and the car works!

Next was fixing the usual "old car" things. Repairing the exhaust, new front brakes, fluid changes, 12V
battery, cleaning dog hair, etc. Had to secure the tailgate external release switc panel with screws and
epoxy. Eventually I will deal with the water leak in the back. Drove it just enough to reset the OBD monitors
for state inspection, when the instrument cluster (CM) went out. So read up about that, pulled the board out
and fired up my soldering station to replace the capacitors. And glued together the center vent trim piece the
broke in the process. That taken care of I could finally just drive the car. The battery "gauge" stays at 4 to 7
bars under pretty much all conditions. I just started using thw Hybrid Assistant app (the update speed is
better than my SnapOn scantool) and it reports about 200mV difference from block to block, with an
estimated capacity of 5.6Ahr.

Now, I must admit that I was surprised by how nicely the car feels. Old school econo boxes were usually
sluggish, flimsy, and really didn't do anything well. Some had good MPG, some handled decently, some
(usually with a manual trans) were a certain bit of fun- even if they were slow- think original VW bug. This
prius is quiet, tight, has decent power. All the widgets seem to work so far- haven't figured out most of them
yet.

My primary car is a 2006 Corolla with 1.8L and automatic. Not a terrible comparison size-wise for the Prius. I drive 80 mile per day, half on state/local roads (30-60 mph) and half on the interstate (70-80 mph). And I get
35-37 MPG. (It would do better if I had a lighter foot and/or the car had an "economy" mode- say only 30%
engine power for the first 50% of the accel pedal- or if it had a manual trans). I try and drive the Prius the
same as the Corolla. So far the Prius claims 46-47MPG- I'll need more fillups to see how accurate that is.
The Corolla has more power on accel (duh!), but at times the automatic doesn't have the correct gear ratio I
need for the road conditions. The prius CVT is much smoother and actually holds speed on uphills better.
The regenerative coasting/braking is different and takes time to get used to.

The Prius rides nicer and has ABS/VSC, the Corolla handles better in turns and no ABS. Prius has widgets,
readouts, and touchscreens- hi-tech but irritating to me for casual day to day use. And it has buttons- MANY
buttons- esp on the steering wheel. Corolla has analog gauges, knobs and switches. It's what I am used to
but it really seems to be less of a distraction. Corolla is a sedan with fold down read seats while Prius has a hatch back- also with fold seats

At this time I like the Prius and will see how it holds up. It is a complex little beast- discounting all the
gadgets and options, it seems like it has twice (100% more) the complexity of my Corolla for maybe 20-30%
better MPG. I am sure the Prius is much better in urban driving conditions. I may have gotten this car cheap,
but it is NOT inexpensive.

 

Just reached 161,000

 

Exactly. I have taken a couple hybrid classes and watched videos, but nothing can replace hands on experience that comes from DOING something for real. Here I can poke and run tests on my car to gain insight as to what things look like when it's working (or when it breaks).

 

Already found and fixed the leaking roof seams- made a thread about it. I guess that Toyota was so intent on cutting weight that they skimped on the sealer-usually they pile it on and never have a leak.
Will keep an eye open for a decent used pack- not a bad idea. thanx

 

So here we are, now reached 170k. Still running (mostly) fine. Last fall I had to do alot of repairs to the hatch glass defogger grid- the type where you use conductive paint on the grid lines. Needed 16 repairs on 12 grid lines, but it works now (don't know if the PO carried barbed wire back there or the dog just liked to bounce off the inside of the glass.

This afternoon just finished a round of maintenance, including a 3-way valve, inverter pump (and coolant flush) as well as the inverter. The old inverter seemed to throw out a bunch of electrical "noise" that caused the engine ecu to set some "ghost" P035x codes every few weeks. I'll see how the replacement does.
Engine uses a quart every 5000- just in time for a drain and fill. Just added an OCC to see what happens. HV battery still looks pretty decent, 0.15 to 0.27V difference and 89% capacity. Going to get new tires soon and likely the radiator as well- it's starting to shed some fins here and there- not unexpected for a 15 yr old car in the lower salt belt.

Any folks who still have the OE HID headlights may want to remove the link on the rear height sensor (for H/L leveling) and lube the pivot joints (or just replace it) as mine was getting a bit dry and stiff.

Keep on "Prius-ing" along.