Do the batteries tend to go bad kinda of suddenly, my daughter did think the mpg had decreased Any sure signs it needs replaced.
yes very sure signs. It will throw a red triangle on the dash but easy to see how healthy it is just use the battery monitor on the mfd. The screen above the radio. It will show you the battery charge level. if its happy it will be many bars of blue if its discharged it will show one bar of orange maybe 2 bars. The behavior of a poor hybrid battery is the car has no power the engine is screaming when you get going because you almost have to floor it to get going and it will go from one blue bar to no bars at a stoplight. It will tank very fast. And get bad mileage no power. And if the car has been sitting most of the time during the covid it will surely suffer. Failed hybrid battery on a G2 is very very common. use the seach forums link up top and search: hybrid battery Btw, failed 02 sensor may be because the cat is contaminated by engine oil. Main reasons people sell there g2: Failed hybrid battery Engine is a little oil eating monster from poor oil maintenance
I agree with Ed, a P0A80 often means a bad hv battery with lower mpgs over a period of time as one typical indication (perhaps 4-6 mpg). Fast discharges followed by fast charges based on the bar graph is another indication. These things will happen for months or years before a serious code appears. Solutions included diy and retail used, often called rebuilt or refurbished. Those solutions are less money but usually last ten months rather than ten years like a new assembly or cells. Some will suggest used is ok because of a one or two year warranty, but they will just give you another used battery, often with a hassle. Dorman sells a used one through auto supplies that looks new because they paint it. Still others believe in special "conditioning" of the cells, but worn out is worn out in most cases. Be ready for sales promises for all solutions. New is reliable and long lasting. Pricing varies widely from $500-$2000 for used or $1600-$3000 for new if you shop around and live in an area with enough hybrids to support independent shops.
Fast discharges followed by fast charges based on the bar graph is another indication. definitely saw some of this but at times it doesn't do, I guess it could just be starting to go bad. I was going to go with green bean company? I saw another post about driving it like this is basically asking for more trouble. Thanks guys
If none of your modules are 1.2 volts less than the others, there is still a chance that reconditioning will help. JeffD
The battery degrades slowly (the modules slowly drift apart in voltage and the cells within each module slowly diverge in voltage) but the computer does not trigger a code until the modules have more than a few tenths of a volt difference. JeffD
Some are getting new Toyota batteries for less than $2k. Apparently the wholesale price has dropped, howver most dealers still jack up the price. Aftermarket new cells NewPriusBatteries Prius Battery Replacement (GenII) Like you've never seen - NEW Cylindrical Cells | PriusChat
You might just need one module out of 28? Do others think that's a bad idea vs whole pack replacement? I used a bluetooth OBD2 scanner and Dr. Prius to see that one module in particular had lower voltage on discharge and higher voltage on charge. Based on this, I purchased one replacement module from HybridAutomotive ($46) , pulled the pack out, found the abberant module with a multimeter, and swapped it. I just re-assembled it and the voltages look even and Dr. Prius says the battery looks good during driving. I plan to recondition it with the Prolong Charger (~$700) and post updates on a thread ( that I can't link to for some reason ) So maybe that'd be a cheaper option, but you/I may have to do it again soon !
