Enginer Range Extender for PIP

Great idea, with the latest generation kit and the PHV built in EV mode they should work really well together!

 

wow, beta testing on my $30-40,000. car? i'll pass.

 

Cover the warranty for anything bumper to bumper for 5 years on my new Prius Plug in and I'd be in.

 

I gotta give it to the folks at Enginer, the PiP, hardly out of the womb - and they're already offering up extended range. What with our shaky economy, that really takes a lot courage. I take my hat off to those peeps for doing what they do . . . helping to extend our limited resources.

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Not to be the Debbie Downer of the group... but wouldn't it have just been easier to buy a Volt? Seems to me by the time you are done you will have spent more money, and have the same cargo room to get less EV miles, and about 7mpg more. Personally I am with the guy that would not want to experiment on a $30k+ car. Is why I got a Volt instead of doing a plug in kit on my regular GenIII Prius.

 

Well Debbie, in 12 months time the PHV will be available second hand for significantly less, so it would be good if the Enginer system was already available. Also, some people already have the kits, and might get them selves the PHV, be cool if the kit can just be adjusted to work. Finally, some people may have a 10-15 mile commute, with no charging available today at work - this kit would help them out. Or maybe their lifestyle means twice a month they do a 1000 mile trip so a Volt is no good, but the rest of the time they have a 35 mile round trip commute. Who knows? If I had a PHV I would sign up, just to push what "can" be done.

 

All good points.. especially the one about someone already having a Kit and can Reuse it. (its that possible).

 

Yeah, unless Toyota made some significant changes (seems unlikely) all that's really required is setting the voltage output of the DC-DC converter to just below the fully charged voltage of the stock pack. It'll then just sit and pour in 14 amps constantly until it's empty. Biggest risk would be getting the stock pack back up to 100%, but this is a risk without an addon pack (if you charged on top of a hill and then regenned down you'd get to 100%) so there will be a failsafe anyway (ICE will be spun to dump electrons). Chance of that happening is also fairly low, since at 14amps it takes a while to refill the HV battery on the non-plugin, would take a very long time to refill the PIP pack. Jack may of course want to try it with a bigger converter, or two converters, if the car will allow it.

It -also- means, that if there's some fancy new cell launched with double energy density of todays, you could easily be adding 8kwh instead of 4. You could even have it modular, so most of the time it's basically an EV with limited loadspace, but can become a regular PHEV by lugging out a few boxes.

 

That brings up the topic of resale value. PHV will be unusually high for the very reason of upgrades later on. Imagine what a few years of aftermarket product refinement will bring... how it will entice those who's warranty has already expired. Electric motors last an extremely long time and the engine in Prius is protected from stress traditional vehicles have to endure.
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I'd be reluctant to try something so radical on a new car. I'm much more comfortable buying a car that does what I want it to. EV + Gen II Prius works best for me. But I deeply admire those who are willing to take a risk to extend the range of what is possible.

 

If my new Prius was of the plug in variety, I'd be inclined to try it. I like innovations. To be truthful, warranty is great for giving peace of mind. However, I've never had to use one on a vehicle that I've purchased new, yet. I've had a couple minor recall repairs but never had anything that required me to use the manufacturer's warranty. Maybe I've just been lucky.

 

IMHO, this is a better application of Enginer and other PHEV kits out there. Implementation is perhaps more straightforward as well. For an extra few thousand bucks, it approaches the equivalent to a Volt. I guess we will find out in time. For a lot of people, this could make the difference between using the gas engine twice a day vs. not using it at all.

 

One has to wonder how the car calculates how much charge the batteries need, and whether you would need to flash the charge controller to include the new batteries. Not to mention cell balancing. If it is using basic voltage and you can use the extended back and stock pack at the same time it would work. If you are using the internal pack, and then the add on to bump the charge of the original pack I think it would be easier & cheaper just to have a regular 110 cord to charge them seperately.

I doubt these cars will be cheap on the second hand market in the near future.. For experimentation purposes it is probably best to wait for one to get totalled, and use the carcass to experiment with this stuff so you don't have to worry about possibly damaging a functioning car. Again it was one of my reasons for not choosing to modify our Gen III Prius.

I am interested in seeing what comes out of this for sure. I have no doubt you guys will succeed, and it will make the PiP a better car. My only question is at what cost will success come.

 

Jack will have to tell us the design, but the simplest implementation, attaching the DC converter to the main relays, means that the Enginer pack could supply approximately 20A in parallel with the main pack using the 5 kW converter (about 4 kW delivery). It is not clear that this is enough power to achieve full range extension at 62 MPH -- it takes at least 30 minutes to deplete a fully charged and balanced Enginer 4 kWh pack with the 5 kW converter -- but the PHV is better used for lower speed commutes anyway. The primary assumption is that there would be no fault generated by the disparity between the current delivered by the OEM pack and the current received by the inverter, as there can be with Gen II.

Think about it this way: Is a $40K car with 11 mile EV range more compelling than a $44k car with 22 mile EV range?

 

The Enginer pack would definitely be charged seperately (its a 48V pack).

The PHV will calculate SOC ussing coulomb counting, as well and looking at Voltage and temperature for compensation. So long as the amps coming from the Enginer DC converter pass through the Hall sensor the SOC calculation will remain correct. No software changes need to occur as the system is alreadydesigned to calculate SOC independently of what MG1/MG2 are doing.

 

The hard part is mounting the Enginer kit safely. I think the voltage also need to be adjusted. If I have a PiP, I wouldn't install the Enginer kit. simply because the space the Enginer would have taken up would be used to carry the spare tire.

 

The voltage is easily adjusted. If I recall correctly, it can go low enough to work with Hondas (144V nominal).

If Enginer current passes through the Hall sensor used by the battery computer, then SoC will not be calculated correctly. The simplest implementation is where the leads from the DC converter are connected downstream of the sensor, to the outboard side of main relays.

The ideal scenario is cruising on 40 [email protected] (about 11 hp and 50 mph), where Enginer delivers 20A, the PHV delivers 20A, and both run out after 30 minutes, 25 miles.

 

Enginer Converter can't sustain 20A output. Also read somewhere the PiP's voltage is higher than normal Prius. If voltage does up, amperage needs to go down. 10 amps is more like it.

 

Alas, I sometimes forget, nominal voltage for GII/GIII is 201.6V. There is no material difference between GII/GIII and PHV (207V). Whether or not you would want the typical converter set point to be 230V +/- on the PHV is a different question, since the discharge characteristic is different for lithium vs. NIMH.

A boost converter like Enginer's 5kW would have an easier time cranking out 20A if it is run at 96V nominal input. Running at 48V nominal input allows for sales of 2kWh kits, at the expense of excessive waste heat generation at full ouput, 4X as much.

Like I said, Jack needs to provide more information to make the case for potential PHV beta testers. My own commute is 15 miles with 500' of elevation gain, at posted speeds of 50 mph or less, and such an add-on would tip the scales to zero-gas usage if I had a PHV.