Hi I've ran the dr Prius battery life expectancy test and it gave me a warning that a weak block was detected. I also drove and tested the voltage difference and I saw it go up to 0.40 and would jump to 0.25 quite often Is that a really bad sign? I've also seen the pack voltage go to 265v and drop down to 198v. Do you think the battery could be the cause of a 6-7 mpg drop in the last 7 months? The engine sounds like its working louder and harder lately.
Yes. Very much so. Check and see if your hybrid battery fan is clean...and the fan filter in the side of the rear passenger seat is clean as well. And start saving for a new hybrid battery.
Beyond a (possibly bad? - don't know) block, your battery looks fine. Mine reported 48% about 9 months ago and I'm still getting a steady 39mpg in town. I'm just waiting for it to give the red triangle of death but it's been holding out ok.
the prolong charger gets good reviews here, but it's unclear how long it will prolong the life of each individual battery. you can try that route (not cheap) or just wait and replace it when the time comes.
there are so many things that can affect gas mileage. tires, brakes, injectors, plugs, coils, throttle body, maf, filters and etc.
The only things I haven't checked from here are injectors and coils, I did run techron and some other stuff multiple times in the gas tank.
Check the rear brakes too. Although I did a check last summer, I just got mine replaced (brakes and rotors) and mpg went form 36 to 39.
