[stwandell]

I’m on my 6th Toyota hybrid. 2004, 2005, 2010, 2008 Prius; 2006, 2008 Highlander Hybrids. I’ve always been disappointed in fuel economy of each of these. Only until recently did I begin to question the details of the hybrid battery and how it all actually works and what can be done to improve fuel economy.

I picked up a traction battery from junk yard for $200 from an ‘08 Prius. I didn’t get the fan because I didn’t know where it was. I had been into my gen3 and it’s right next to the battery. I have been experimenting charging individual modules, the entire set of modules in parallel, balancing in 7.2v parallel and finally buying an LED driver rated at ~257V at 350ma. I have had some glitches when trying to get 12v power to fan while using grid charger. I’m guessing there is more to it than connecting an AC adapter putting out 12v at 3amps to the fan… it just pulses. So I just put a spare 12v in the back and connected leads to power the fan while “grid charging”.

I now have a reconditioned battery in my 2008 Prius and I have an entire spare traction battery and trying to figure out what to do with it. I had briefly considered a parallel configuration traction system but decided that was more complex than I wanted to even attempt. However, the idea to take the extra traction battery and configure it as a giant 14.4v battery connected in parallel to the 12v yellow top optima has me wondering… anyone else tried this? Benefits, risks, anyone tried it before?

Shawn