Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - DIY "Mild" Plug-in Prius Project: Grid-powering the 12v side w/ deep cycle batteries

orange4boy · 11-30-2009, 04:43 AM

Exciting news!

I tried a few simple experiments with the NHW11.

I disconnected the main 12V supply wire from the inverter. The larger grey connector/white wire below the MG2 main cables at the back of the inverter. Started the car and got P3004 Power Cable Malfunction (Prius), P3125 Converter & Inverter Assembly Malfunction (Prius), triangle etc. Still ran.

Hooked up my 50A switch mode battery charger to the 12V battery and set it to 50A. ~ 14.5V Codes and triangle remained. Cleared codes with Graham scanner

... turned off car and started again... Ran fine, no codes, no triangle.

Running load showed a little less than 20 amps. I tried fans and lights and some other loads which added to that but not as much as my van. Apparently they have designed some pretty efficient electrics in the Prius. I will try to do a detailed study of the loads if there is no other reference.

Then I shut off the car, disconnected the charger and started it on the 12V battery alone. It worked and the codes did not come back. All the way down to 11.3V

Then turned off the car and plugged the inverter connector back in. All good and showing 13.8V at the battery.

My question is why did the codes not come back when I ran with just the 12V battery the second time? Does the ECU ignore faults for a while after you clear them?

Conclusion: The car runs on just the 12V battery with the main inverter supply wire disconnected. This means it should be a fairly simple thing to supply the 12V system with plug in juice. I may ultimately need a good 100A DC-DC converter for whichever battery pack I decide to use. Hopefully the voltage is the trigger in which case one simply must keep the supply above x-volts to keep the ECU happy.

We shall see.

11-30-2009, 04:43 AM	#14 (permalink)
orange4boy Master EcoModder Join Date: Aug 2008 Location: The Wet Coast, Kanuckistan. Posts: 1,275 The Golden Egg - '93 Toyota Previa DX 90 day: 31.91 mpg (US) Chewie - '03 Toyota Prius 90 day: 57 mpg (US) The Spaceship - '00 Honda Insight Thanks: 100 Thanked 306 Times in 178 Posts	Exciting news! I tried a few simple experiments with the NHW11. I disconnected the main 12V supply wire from the inverter. The larger grey connector/white wire below the MG2 main cables at the back of the inverter. Started the car and got P3004 Power Cable Malfunction (Prius), P3125 Converter & Inverter Assembly Malfunction (Prius), triangle etc. Still ran. Hooked up my 50A switch mode battery charger to the 12V battery and set it to 50A. ~ 14.5V Codes and triangle remained. Cleared codes with Graham scanner... turned off car and started again... Ran fine, no codes, no triangle. Running load showed a little less than 20 amps. I tried fans and lights and some other loads which added to that but not as much as my van. Apparently they have designed some pretty efficient electrics in the Prius. I will try to do a detailed study of the loads if there is no other reference. Then I shut off the car, disconnected the charger and started it on the 12V battery alone. It worked and the codes did not come back. All the way down to 11.3V Then turned off the car and plugged the inverter connector back in. All good and showing 13.8V at the battery. My question is why did the codes not come back when I ran with just the 12V battery the second time? Does the ECU ignore faults for a while after you clear them? Conclusion: The car runs on just the 12V battery with the main inverter supply wire disconnected. This means it should be a fairly simple thing to supply the 12V system with plug in juice. I may ultimately need a good 100A DC-DC converter for whichever battery pack I decide to use. Hopefully the voltage is the trigger in which case one simply must keep the supply above x-volts to keep the ECU happy. We shall see. __________________ Vortex generators are old tech. My new and improved vortex alternators are unstoppable. "It’s easy to explain how rockets work but explaining the aerodynamics of a wing takes a rocket scientist. Last edited by orange4boy; 11-30-2009 at 04:54 AM..