Hack Your Prius With Prius Batteries


Adding extra battery capacity to hybrids is becoming pretty common, but this one is better than the average lead acid trunk fest. The pack was built from three prius NiMH packs picked up from salvage yards. These batteries can’t simply be bolted together, but with some research and effort you can save some nickel from the junk yards and cut your fuel bill.

9 thoughts on “Hack Your Prius With Prius Batteries

  1. Im suprised no one has commented on this, so I will. Ya the prius is ok, it looks like a blunt end turd but oh well. I’m a big vw guy so I’m use to getting made fun of liking ‘ugly’ vehicles. Extending the range is cool, but it would be cooler if one could reprogram it to operate it off of batteries alone at speeds upto 65mph. That would be more useful in my book, esp b/c I drive 30 mi one way at highway speeds.

  2. Prius maximum speed running off of the electric motor is 43mph. To enable the electric only mode, you simply mod in a button (non north american models already have them).

    You would also need to add plug-in capability to charge from mains.

  3. @thegimpster

    you can’t reprogram it, max mechanical speed on batteries only is 42 because of upper rpm limits of the 2 motors. Well, one is a motor, the other is used as a generator or a motor depending on if its being driven or if its driving. They do have a plug in dongle that makes it so you can drive only on batteries with the flip of a switch, but still, mechanical limits stop it at 42… which is ok… but I agree it would be nice…

    and 30 mi on batteries, not likely on batteries alone on a prius, not at 65

  4. Actually the max speed is 52 mph, I have done it with a hack. this is the upper rpm limit aparently of the electric motor.
    The Hack is similar to out of gas mode only better because the car does not have trouble codes and does not try to start the I.C.E.

  5. The effort to hack a Toyota hybrid system is not worth it. I was trying the same method I used to hack the Honda 1st gen Hybrid system by putting a bigger battery in 06 Highlander Hybrid. Was able to swap in a 7.4kwh battery bank that sit in the trunk. Unfortunately the Toyota computer is hard to trick. It only knows capacity as the stock 1.9kwh so the extra power is not usable. The only way a extra battery can give the hybrid system more power is through the over charge protocol, which is what all plug in conversion kit uses. By pushing voltage above 340V computer will read over charge and force the hybrid system to quickly get rid of the extra voltage by using more assist before the hybrid battery burns up due to over charge. Down side to this setup is unable to regen the extra capacity of the add on battery and possible over charge and damage of the original battery. After a month of testing the improvements to the mpg minimum at best. Not worth the money and time used to build the circuit boards and connection to make this setup work.
    But my other project Honda first gen Hybrid system found in the 00-06 Insight and civic hybrid is hackable to accept a bigger battery and give you 100% control over the assist and regen function of the hybrid system. Was able to obtain 150 mpg avg over 38 miles (which is the max calculable mpg on the Honda, so might have been over 150) with this setup in a 00 Insight.

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.