Dear Richard Schumacher . . .

I cannot thank you enough for your incredibly helpful guide to testing the battery, Weird stuff happening? MPGs dropping? Test The Battery: Here's How.

We bought our first Prius, a 2007, in January, and have been delighted to own it and drive it. But, this past week the mpg readout on the MFD was all over the place, bouncing from high to low. We were hoping it was just a fluke, but then filled up the car and checked the mileage. We were, in fact, down to the mid 30s from being at a steady 45 mpg since we bought it. So we searched the forum and found your guide. My husband, who was mighty reluctant to touch such a complicated car, walked through your steps and says they worked like magic. He is, btw, a former technical writer who says your directions were clear and beautifully written. We got a new Optima battery and he was able to put it in himself with your help. We've only driven the car 20 minutes or so since then, but it's clear that things are on the mend. The mpgs are slowly going up and appear to be returning to normal. The car was on its original, factory issue battery, so whatever happens from here on out it clearly needed to be replaced anyway. But we are 99% sure our problem is solved.

Thank you from the bottom of our hearts.

Cheers,
Kitty

P.S. My husband would like to offer this addition to the instructions. In paragraph five, you might want to mention that the "red cap" is, indeed, under the hood, but you have to open the fuse box to see it.