[mwebb]

i recently bought a 2002 prius with 50200 miles ,
it had no faults in any system and no warning lights for anything
passed NYS safety and emissions inspections

was good for 100 miles
then
several cells in the battery began reporting uneven voltage at rest values , greater than 300mv difference
and the one internal harness was bad reporting 0 volts on cel 12 which did not agree with measured value
remove battery , disassemble the harnesses and replace the harness with the sensing wires $169.oo from toyota , charged the lowest cell in the pac at regulated 100ma 8v untill it held about 7.5 volts like the rest , reassemble
back into the car , good for 25 miles and battery cooling fan goes to MAX , battery discharges on the 5 miles to home .... HV ECM reporting all temp values at -40c when everything is connected ..... pronounce HV ECM and the battery assembly .
generic "obd2 scan reader " will NOT reveal contents of HV system(s)
( i should add here that i am certified by VW to repair their HV Hybrid products and have scopes and DVOMs and scan tools to fuss with this )
remove condemned HV battery assembly
new reman battery from greentec with gen 3 cels 90 minutes to drive to pick it up x2 .... install that battery and
KAKA = KAKA
from "new" KOEO we have p3009 HV leak somewhere , since it sets KOEO
KOEO = key on engine off

it is the battery as nothing else is in the HV circuit until engine start .... some drama explaining to greentec that their internally dust coated ? HV battery had an HV leak , in the end they stood behind their product and , remove KAKA battery , back to NJ x2 90 minutes each way .... install battery 2 from geentec and all is well ,
total into the car so far = about $3800.oo not counting my time

AC is intermittent ...when it fails .... blinking green on AC button .... so more drama to follow ..... BUT battery and drivetrain are now happy
was it worth it ?
yes
imho ,
the car is clean and i had some 15" 4x100 steel wheels for a yaris that had tires i bought for the now retired geo metro
which bolt right up and 195 60 15 tires fit in the wheel wells ... so far ...
this is a huge improvement , the green graphs are showing many of the recorded segments are well over 50 mpg .... to early to tell what recorded values will show ....

the original 14" 175 65 14 tires / wheels are pathetic and very scary to drive
at any speed on a twisty road ....

having said this
my VW TDi is a much better car .... my wife likes the prius ..... i like the TDi

i have been working on AC systems much longer than Hybrid systems
whats the worse thing it can be ? life is no good without some drama

hint
use a 2x8 when removing battery , through the trunk , no heavy lifting inside the car
just drag battery up the 2x8