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 · 01-31-2010, 04:05 AM

I just disconnected the DC-DC converter output and hooked up a deep cycle battery. Ouch! The Prius is an electricity pig. This may give greater returns than I expected.

Normally on my Previa, with a fully charged battery, the voltage stays above 12V for a couple of miles before it settles around 11.8 and slowly drops from there.

The Prius sucked it down to 11.4 right off the bat and below 11 with the low beams on.

The ECU seems to decide to throw a code only after the voltage drops below 12. I will have to try this again and see if hooking up a 14.4 v battery to the sense wire does the trick. That way I don't need a DC-DC up converter to get 14.4 out of the 12V deep cycles.

Then, the next time I'm under the inverter I will install a big old disconnect in there so I can fire up the DC - DC when the deep cycles are flat.

01-31-2010, 04:05 AM	#32 (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	I just disconnected the DC-DC converter output and hooked up a deep cycle battery. Ouch! The Prius is an electricity pig. This may give greater returns than I expected. Normally on my Previa, with a fully charged battery, the voltage stays above 12V for a couple of miles before it settles around 11.8 and slowly drops from there. The Prius sucked it down to 11.4 right off the bat and below 11 with the low beams on. The ECU seems to decide to throw a code only after the voltage drops below 12. I will have to try this again and see if hooking up a 14.4 v battery to the sense wire does the trick. That way I don't need a DC-DC up converter to get 14.4 out of the 12V deep cycles. Then, the next time I'm under the inverter I will install a big old disconnect in there so I can fire up the DC - DC when the deep cycles are flat. __________________ 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.