Newbie and need traction batt info

Congrats... Welcome to our slow driving vehicle geekery... There's always more to learn about Prius...

On PriusChat back in the day we used to compare Toyota recalls and warranty to BMW... It was often said, who else but Toyota will do free recall repair work on 10 year old cars? Then someone would chime in about the opposite way that BMW does it compared to Toyota.

Anyways, if you want to learn how your battery pack is doing... Pull the pack for cleaning, inspection, testing and reconditioning. Getting spread sheet data on the status of each of the 28 modules will be valuable in maximizing the life of the battery pack, as well as replacing a bad module before it heats up and damages other modules is the way to go.

The copper bus bars connecting the modules will have plenty of corrosion for you to clean off and because the modules use a very limited amount of charge and discharge range in the car, the electrolytes get stagnant and need several discharges and recharges to revitilize them / improve capacity / lower resistance.

For load testing use a headlamp lightbulb to measure voltage drop of each module over a 2 minute period. For recharging an individual module my friends and I use the Sky RC smart charger version 2, which is a battery charger for remote control drones, cars, toys, etc. Once you get the load testing numbers written down, you'll be more clear on which modules are stronger and weaker, which ones to keep an eye on.

Then you can get lots more data using two headlamp bulbs to discharge each module down to 6.5 volts and recharge again, then down to 6 volts and recharge again, then down below 6 volts, but keep a close eye on it because below 6 volts these modules fall off a cliff in voltage at that point and if your forget you're discharging polarity could reverse and you'll have to buy a replacement module.

Alternatively you could spend a sizable chunk of cash on a Prolong system that will do all this work to the whole pack at once, but where's the fun in that? http://hybridautomotive.com/pages/faq

In my experience the improvement in hybrid battery health after conditioning is significant and worth the time it takes...