Installed kit from Plug in Supply getting 28 miles!

Have been driving for several days and ev miles are between 26.8 and 28.1 ev miles, so far. Average mileage after Ev is gone seems better for a while also. The car still gets some extra current from added battery for some time even after EV is off. Install was easy. Plug in supply has this kit ready for sale now and it works great. This product can be found on his diy web site.
I will post photos soon. By the way, now this car gets almost the range of a Volt, but after Ev is gone, it gets 58 to 69 mpg instead of the 30 or so mpg of the volt. I am really glad I chose the Prius now.

 

I have a separate battery charger for the added battery. Using the prius charger is not as effective. I plug in both at same time and on 120v they both finish in 3 hrs. I can charge just the prius on level 2 in 1.5 hrs if in a hurry for short trip during the day. I am finding that I get enough miles ev from the start of the day that plugging in during the day is less important. 100% of my local driving is now ev, was 50% before.

 

Isn't that much better than rated? How do you do that.

 

Simple to remove. Unplug 2 wires and lift out 2 battery boxes at 43 lbs each. Weight is 86 lbs for batteries and less than 10 lbs for the relay and circuit board, which I will leave in. I drove 160 miles yesterday at 55 to 65 mph and average mpg was 72mpg for entire trip, and 62 mpg for second half of trip with no ev. I used both trip counters to keep track. I let one run for whole trip and reset the other for the way back.

 

Since I had already installed a leviton level II charger at my house, I use it for the prius (checked current with amp probe at breaker box, 8 amps at 240 volts) and charges in 1.5 hrs. I plug the other charger into 120v outlet (4.5 amps on the ac side at 120v for 3 hours. Both chargers turn off automatically when each battery is fully charged. At night I set the timer for the prius to be finished shortly before I leave in the morning, as Toyota recommends, and just plug in the add-on charger at night. I have a switch which allows me to choose when I use the add on battery.

 

Prius battery: lets assume about 2.7 kw being charged. 8 amps x 240 volts = 1920 watts x 1.5 hours = 2880 watts 2.88 kw. Add on battery: Let me state more clearly. 4.5 amps 220 volts on DC side to battery. 9 amps x 120 volts = 1980 watts x 3 hours = 3240 watts 3.2 kw. If you factor in the losses in the chargers it works out about right. I hope I explained this clearly. I know how it works better than I can explain it.

 

What mpg are you getting after ev miles are gone?

 

if you get a more accurate figure let me know. Thanks