The Prius traction battery died at $190k miles which was a little disappointing. The Toyota dealership wanted $5,000 for a new one! I found several companies that assembles new batteries from individual modules and supposedly "recondition" them, even providing limited warranties.

Figuring I had to take the battery out anyway, I pulled it by myself and disassembled it in the garage. I simply measured the voltages across each of the 28 modules and found 3 that were considerably lower than the others. I ordered 3 on Amazon for $30 each, put it all back together. And it worked! .....for about $6,000 miles.

So I bit the bullet and ordered a "reconditioned" unit for $1350 plus shipping, supposedly a Gen 3 pack to replace my Gen 2 pack (i.e., newer battery). It had a 12-month, 12,000 mile warranty (same as Toyota for $5k battery!). It lasted about 30,000 miles and two years, instead of the promised 3 to 4 years.

I've done enough research to understand that there is no good way to match up 28 modules, it's pretty much whack-a-mole. If I did it over again, I'd buy a new battery from newpriusbatteries.com. Anyway, the car has $230k on it, bad struts, hail damage, etc. It's time to put it to bed.

The car has been a real trooper, it's saved us many thousands of dollars over the years in fuel costs and maintenance. I just now replaced the front brake pads the first time at 225,000 miles. If the whole car was in better shape I'd spring for the battery. Takes about 4 hours to change it.

Recently I had my Toyota Prius serviced at the agency from which it was purchased, Kendall Toyota of Eugene, Or. The 12 volt battery needed to be replaced. I asked to see it tested and sure enough, the center cell was dead.<p>  The mechanic had the new battery ready to put in and I could read the label.

It was a 12 volt, lead-acid battery with an inaccessible vent opening. I asked why there was a vent since both the Service Agent and Mechanic agreed that it was a Gel-type battery. They offered no answer to my question. Gel batteries do not have a vent. Lead-acid batteries must be vented and they must have cell access in order to check the cell electrolyte level and replenish it if necessary. Failure to perform a regular test on electrolyte level results in early battery failure.

The reason I asked was that I had to pay for a new battery at $203.02, and the charge for resetting the computer was $95.00. That was why I wanted to see the old battery tested.

A week later, I asked some questions about how long the battery would last with certain loads and the engine not running: radio, dome lights, headlights, etc. I also asked how to reset the computer if the battery died and was recharged. I was told that the computer would reset itself !

I have been misled ( lied to ) and overcharged. I am I being overcharged for labor, and I am being overcharged for the battery.

My Background and Argument: A small capacity lead-acid battery costs no more than $50.00 A Gel-type battery costs about $75.00, of comparable size.

I am basing my argument on my own expertise as a former Professor of Electrical and Electronic Engineering, plus years as an Engineering Consultant. In addition, I maintain 12- lead acid batteries in my solar electric system, plus an additional six Gel-type batteries in an all-electric car I own. I have also written a book on Solar Electric System Operation and Maintenance, half of which is a discourse on batteries.