View Single Post
Old 01-27-2014, 08:35 PM   #191 (permalink)
Master EcoModder
IamIan's Avatar
Join Date: Dec 2010
Location: RI
Posts: 678
Thanks: 368
Thanked 220 Times in 136 Posts
Originally Posted by HyperMileQC View Post
The "Phases" you are talking about is the switch held on (Phase-I) and the switch relased after engine cutoff (Phase-II) ? If this kill the engine like when you key EOC, then you could really bump start like I do. Not with the electric motor.
Phase-I is while my FAS button is being held down ... in this phase it is cutting the fuel injectors ... and the engine stalls... that it similar but a bit different from Key off type.

Then in Phase-II I release the FAS button ... but the FAS mechanism holds a faked clutch signal ... I even use this Phase-II when I get OEM Auto-Stop ... I don't have to hold the clutch to hold the Auto-Stop.

I have bump started from FAS.... the electric motor is not needed to restart from FAS ... the electric motor can be used ... but it is not needed ... but you do have to leave Phase-I ... because as long as you are in Phase-I you are cutting the fuel injectors and the ICE can not restart... Even if I use the IMA to force the ICE to spin, there will be zero combustion with zero fuel.

Originally Posted by HyperMileQC View Post
About the DC-DC...

If the signal is normal the DC-DC converter default condition is alternator like mode. Then if you cut that signal with a switch. The DC-DC converter will stop working in alternator like mode until you return to OEM signal, right?
You're backwards.

The only signal the car sends to the DC-DC is to tell it to stop and turn off. If you cut the control wire ( or temporarily break it via a relay or switch ) the car is not able to tell the DC-DC to turn off.

Without the car telling the DC-DC to turn off ... by default it will stay on in Alternator like mode as long as it has IMA high voltage battery connection.

Originally Posted by HyperMileQC View Post
Then what doesn't work? What I was thinking about is a way to decide if the DC-DC converter works in whatever condition it wants or is OFF. I was not talking about the DC-DC enable thing. Why would I want to charge my 12v battery even during OEC when what I want to do is make the DC-DC converter work less often. You could compare this idea to an "alternator ON/OFF switch" on conventional cars.

90% of my mileage is short trips. So I could let the DC-DC converter off all the way and charge my 12v battery at home without problem. I want to save the 144v juice for assist and also to charge less often.
It's your car and is up to you ... but there are many reasons to want to be able to still have 12V alternator function while in FAS and not burning any fuel.

You can charge the 12V battery at home instead of in the car if you like ... just be careful ... lots and lots of things you need operate from the 12V system ... and the OEM 12V battery was sized under the assumption you would have DC-DC alternator like function available to recharge it... there is also a minimum amount of 12V battery needed for the 144V system to work ... if you drain the 12V too low , you won't have any assist available , even if the 144V battery is 80% SoC... if that happens your idea of saving 144V energy for assist is mute as you can't use it, if you drain the 12V too much.

You can also charge the 144V battery at home if you like.

  Reply With Quote
The Following User Says Thank You to IamIan For This Useful Post:
HyperMileQC (01-28-2014)