DIY "Mild" Plug-in Prius Project: Grid-powering the 12v side w/ deep cycle batteries

[orange4boy]

But she's a fuel hummingbird

I did say electricity pig, not energy pig. Poor choice of words. I should add that the climate control fan, for example, is very efficient compared to my Previa. The electric steering assist is very miserly too and draws nothing when not in use. Compare that to a power steering pump on an ice car that eats ~200-400 watts base load.

Of course it's all the electrical do-dads that allow the Prius to be more efficient. There is no such attention to efficiency in the average ICE car.

And the in-out efficiency of the Prius is much higher so those watts require much less fuel to make.

The other thing is that the battery I'm using had been sitting for a few months and needed "waking up". I based that pig comment on the voltage sag, not the actual measured watts.

I guess I should go apologize to my car for a poor choice of words. (and Bob too)

[bwilson4web]

LOL!

Look, we're talking about overhead loads that in any other car forum would not even be understood, much less considered. I mean it is a hoot to see some of the ... "DOGMA DEBATES" ... advocated by camps of diesel, aeromodders, hypermilers, EV or others instead of just kickin' off our shoes, listening and having a gab-fast sharing facts and data.

OK, now I'll have to ban myself for a couple of days while the usual suspects have a field day. One last thing ... a tale of 'great expectations.'

A newbie poster visited another forum with some technical questions about his NHW11 Prius. Since he is up in Tenn., just 3 1/2 hours away, I volunteered to come up next weekend and help. His next post was:

Are you a "certified technician?"

So of course I apologized that I was not a "certified technician" and only had 5 years of self-maintenance of my NHW11, the full shop maintenance manual set (dog eared and dirty pages) including the wiring diagram, a Graham scanner (able to read engine, hybrid vehicle and battery controller codes), my own tools, a spare inverter (the part he was replacing) and photos of when I removed my inverter to get to the gap between the transaxle and firewall. I guess he thought that forum was populated by "certified technicians" who were anxiously waiting to answer his every question. <SIGH>

Well I might as well go stand in the corner now ... banging my head against the wall (not bloody likely!) Time for a break since my workload has picked up. I'm looking forward to hearing the 12 V plug-in experiment results.

Bob Wilson

[orange4boy]

By the power vested in me by the EcoModder brotherhood, I hereby declare you a certified, bona-fide NHW11 Prius technician, fifth level, Master of the Graphs.

There ya go. I can do a doctorate for you too bit it's gonna cost you.

I read that post. Pretty funny. I bet the dealer gave him a song and dance about that.

It's a unique forum, this. Prius chat is good too but very different. Did you catch the guy who called me a "Prius fan boy" for commenting under the 2010 section? I LOLed my A** off. We have our share of "characters" here too. The internets are a fascinating place.

We're glad you joined us. Too bad this continent is so big. I'd love to go to an Ecomodder rally. It could be like the Oskosh of Ecomodding.

[orange4boy]

Do you know which of chose major devices run off 12V vs the HV pack?

Sorry for the late answer. In the NHW11, all of the systems are run by the DC-DC converter output. In the 04+ I think the A/C ?might? be high voltage but I'm not sure of that. I think for safety they have kept the HV cables the only HV wires in the car.

The 12V deep cycle battery alone does not work very well in the Prius. The load is so much greater than in a regular ice that the voltage drop is too great with one 12V battery. Mind you, I'm using a revived battery for now. I have to get a pair of my fresh batteries in there. I'm going to fork over for a decent 13.8V DC-DC pretty soon because I'm convinced this mini plug in will make a pretty big difference in mileage.

[MetroMPG]

Originally Posted by orange4boy

In the NHW11, all of the systems are run by the DC-DC converter output.

Sorry for slightly OT - but does this mean that salvage Prii might be donor candidates for 12v vacuum pumps for converted EV's?

And back On T: any more news on the project?

[bwilson4web]

Originally Posted by MetroMPG

Sorry for slightly OT - but does this mean that salvage Prii might be donor candidates for 12v vacuum pumps for converted EV's?
. . .

Not that I know. The NHW20s and later have an electrical air conditioner compressor but it uses a high voltage. The hydraulic brake accumulator pump is 12 VDC but this is a low volume, high pressure application.

What do you want the 12 VDC vacuum pump to supply? Brake boost?

Bob Wilson

[orange4boy]

Update:

I had the wipers and cowling removed to install the circulation tank heater and used the opportunity to install a solenoid in the main 12V power lead from the DC-DC converter. The solenoid turned out to be dead, the victim of my 18+ volt Previa experiment. I will be picking up a new solenoid this week.

The plan was to be able to disconnect/connect the DC-DC at will. For experimentation, I will have a couple of batteries hooked to my 750 watt inverter, powering my 50A charger which will act like a power supply and keep things in the 14V range. I will keep track of amps so I will know how to size my DC-DC.

I would like to keep the 12V battery in line in case of failure of any one component but would like to figure out what I can do to keep the voltage it sees <13.8V. That way it won't get cooked by the 14.5V from the charger. I need a 1 to 2V drop with enough current capability to take over in the event of any shut down.

Ideas?

Eventually, I will find a 13.8 v DC-DC converter to run off the battery pack directly and thus avoid the DC-DC failure codes.

[Daox]

I really like the little dc to dc converters I got (that I still haven't used). But, we need to find a way to beef them up a lot. As is, they're ~60W.

Universal Car Charger Adapter Power Supply For Laptop - eBay (item 250557155006 end time Apr-02-10 02:30:55 PDT)

Here is a thread I started a while ago when I found out about them. The autospeed article linked there tells you how to get more power out of them. But, you're not gonna get the 300W you need to run the Prius out of one without some major upgrades I think. Perhaps I'll bring one of these to the next EV build day and see what the guys there think can be done about uprating it (run multiple components in parallel or something).

http://ecomodder.com/forum/showthrea...ders-9461.html

[orange4boy]

I like the idea of beefing them up. If I was more of an electronics geek, I'd be making my own. It would be good to find out the quality of the power as well. I would hate to be supplying all that nice silicon with "Chinese dog food".

I did find a few cheapo ones with higher watt ratings yesterday:

The second one looks like a better value but the quality and ratings are suspect of course. I'm going to assume the ratings are peak and the constant output is around 70% of that.

Adjustable DC-DC Step-up Converter In 10-16V Out 12-48V

24V to 12V DC-DC Car Power Supply Converter 30A

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