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Old 11-29-2009, 07:44 PM   #11 (permalink)
bwilson4web
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Quote:
Originally Posted by orange4boy View Post
This has been done before so hopefully I will be able to get some specific info before I do anything:
http://www.veva.bc.ca/articles/PHCdemoArticle080211.pdf

I will try to get some information from the owner, who is a member of VEVA and has rebuilt several Prii:
http://peopleshybrid.com/index.htm
Excellent! I always enjoy using the fruits of proven technology ... <GRINS>
Quote:
Originally Posted by orange4boy View Post
. . .
I like that idea better. 24V is better because it seems to be easier to find and implement a down converter than a boost converter. Also, I will need at least 2 batteries if the overhead is indeed 300+ watts. I'm not concerned about the extra weight because it's well known that cutting ICE electrical overhead outweighs the added weight of batteries. Ha Ha.
My old man's brain may not always be the swiftest ... but occasionally even a blind pig finds an acorn. <GRINS>
Quote:
Originally Posted by orange4boy View Post
. . .
Questions to be answered assuming a 12V nominal system:

Will the lower voltage (under 13.5V) set codes?
Once the car starts, the inverter provides enough voltage to run without a battery. Good Prius friend Hobbit performed that experiment.

Quote:
Originally Posted by orange4boy View Post
. . . My guess is that it might if it gets too low. Prii with dying 12V batteries exhibit all kinds of strange behaviours. Although a dying battery will probably be sub 10V under load. The graham scanner sees 11.3 on mine with the hybrid system off so there seems to be some flexibility.
That is the funny thing. We find intermittent problems that suddenly disappear when a good aux battery is installed. My OEM battery lasted until January of this year ... 4 years? I had to change it before flying to Detroit in January.

Quote:
Originally Posted by orange4boy View Post
. . .
I noticed, from the EWD that there seem to be quite a few different blocks or busses. I was thinking, If there was a simple way to keep the DC-DC happy by leaving it to run the ECU's, or at least the engine bus then it would be less likely to set any codes. I have noticed on my van that some sensors (eg. coolant temp) read low when the voltage gets low.
All the right questions.

Quote:
Originally Posted by orange4boy View Post
. . . What is the electrical efficiency of the THS from ICE (35%eff) to MG(?%Eff) to battery(?%Eff) to DC-DC(?%Eff) to 12V? How does it compare to a regular ICE(20%Eff) belt(?%Eff) Alternator(45%Eff) 12V?
To the best of my knowledge, no one has done a through job of researching this. I have fuel consumption figures for my inverter setup but I've not tried to work the problem back to the source(s).

Quote:
Originally Posted by orange4boy View Post
. . . Is the DC-DC a simple load based unit? Will it just supply what is asked of it and no more?
Once I start drawing 1 kW, the voltage drops off keeping the 1 kW power but now with more amps and less volts.

Quote:
Originally Posted by orange4boy View Post
. . . What happens to a stock Prius if the DC-DC goes offline while driving? If the car still operates then we know it would be possible to simply substitute the 12V supply. (better if 13.5V)

Will it be a simple/desireable thing to supply some blocks with 12V and some with the DC-DC?

Should I have a relay set up to switch between systems for long trips when the batteries get low?

Fun stuff.
Fun stuff indeed! I've not tried that experiment but you are asking the right questions. <GRINS>

GOOD LUCK!
Bob Wilson

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2019 Tesla Model 3 Std. Range Plus - 215 mi EV
2017 BMW i3-REx - 106 mi EV, 88 mi mid-grade
Retired engineer, Huntsville, AL
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