3rd gen had a issue with the hibryd ecu 2 of the pins were coroded so I changed the ecu and wire harnes used the car a little then it sat for several months and when I went to start it well then same place but this time all burnt up and the first 4 cells totally dead charger says there is a short in those first 4 cells
This is way more common in gen2 rather than Gen3 and is because Toyota insists on higher profit/greed from using 1990's antiquated Nickel-based battery chemistry that leaks toxic corroding chemicals at the terminals rather then the rest of the auto industry who is currently burying them in a shallow grave with more modern Lithium based battery power. On the bright side, you can buy a new voltage sensor harness that includes the fried plug for less than $100 and if the pins of your battery ECU plug or internals of ECU is fried you can get a used one online for about $100. So with a little DIY labor you're looking at less than a couple hundred dollars out of pocket and you're back on the road. Of course if you rely on the criminals at a Toyota stealership it's near $1000 for new ECU & harness, plus labor and made up other parts needs scam you for as much as $2K.