Enginer PHEV Test Pilots: Mpg reports and important data

Initial impressions with the Enginer 4KWh system have been EXCELLENT! This is exactly what I've been planning since well before getting my Prius in 2006. This system delivers the extra charge that I've been needing to extend my driving efficency under many conditions. It also feels great to be driving on Solar power! Monitoring various parameters using ScanguageII (most often SoC, BTA, RPM & LHK) has helped me to make the most of the extra available energy.


For those who do not have a scanguage or prefer to use only the Prius MFD while driving, the following chart might help you to maximize use of stored charge in your Enginer PHEV system and perhaps further increase your efficiency. This is certainly not a replacement for a scanguage since this will only give you an idea of the SoC, and only at the times when the battery bar graph changes. Note that the transition points on the bar graph are different when charging and discharging the Prius OEM traction battery.



For example, when decelerating/regenerating or at a stand-still and current is flowing into the traction battery, the appearance of the 7th bar (1st green bar) on the MFD means the SoC is approximately 66.5%. However, when accellerating or in EV mode where current is being drawn out of the traction battery, and the 8th bar just dissappears (ie. also at a 7bar display), the SoC is approximately 73%. Unfortunately, this does not apparently mean that the 7th bar represents a SoC in the range between 66.5 and 73% because as discharge continues to the point when the 7th bar just disappears, SoC is reported to be approximately 64%.

The current being delivered to the HV bus from the Enginer system varies dynamically but while stationary, current flow into the OEM pack often seems to hover between -7 to -9.5A. This typically means that the traction battery gains 0.5 SoC approximately every 10-15 seconds (A/C off, heat off, fan set to second level--Lo+1). Of course deceleration regen can deliver a much higher current depending on many factors, (including speed, rate of decel/braking rate, battery temperature, etc) and related parameters (including Charge-Current-Limit (CCL) and Discharge-Current-Limit (DCL)). For example, if the battery temperature is below ~32deg C regen current appears to be limited to the -45A range. But a warmer battery (perhaps over ~36deg C) might see currents as high as over -90A during regen.

The Prius likes to keep the traction battery near 60% SoC. So if SoC is higher, it makes greater use of this stored energy. If SoC is too high it will try to drain power from the battery. And if SoC is too low (<45% SoC) it will start the gas engine to help recharge the battery. Observations seem to indicate that maintaing a SoC in the 65-75% range produces some very efficient results with mainly gentle city driving (currently averaging ~2.1LHK (~112MPG), ~5% highway, ~25km/h avg, temperatures ranging from 15-26deg C (~60-78F)). A full charge appears to last for about 45KM/28 miles of driving. Of course, results will vary with traffic/driving/road conditions, driving style and climate.

One last pointer -- even when in EV mode, letting off the accelerator and gently re-applying, after attaining cruising speed can often reduce current draw from the battery and perhaps extend EV range.

Please feel free to share other observations and experiences even if they differ from what is described above. I am very pleased with the results from my 4KWh Enginer system thus far!

Cheers!

 

Although the charger and the converter are isolated and it won't damage the system with both on, it is not recommended to do so since the smart charger is not smart enough to know why the battery voltage fluctuates (because of discharging at the same time) and won't work correctly.

 

As I said in the other thread my first test drive on Wednesday (1 day after my install) I drove around almost exclusively with electric only for about 25 minutes and scored a series of 2.5 L/100km bars on the MFD. Nearly the whole time, the OEM SOC was 5 or 6 bars. I accelerated hard with the ICE and maintain my speed in long cruises on electric only. (after accelerating, I let my foot off the gas and put it back down lightly to fire up the electric motor only).

I don't think I came anywhere near to emptying the pack. 4kWh is a lot apparently when driving in the manner described above. Not sure what I would do with 8kWh.

I've checked my voltages a few times before and after charging and found them to range from 3.30 (partially depleted) to 3.37 (fully charged). The batteries were also balanced pretty well right out of the factory.

I'm curious to find out what the voltages are when the pack is drained enough that the red light comes on on the dash switch.

Tonight and tomorrow I'll be doing some serious driving around so I'll have a lot more data.

Once concern I have is the smell. 3 of my batteries were a little scorched looking near the terminals. My kit is a bit smelly perhaps from that or perhaps from the newness of the electronic bits in the converter/charger getting warm for the first time.

Also after I unplugged the charger, the red/green lights flashed on/off about 3 times and it clicked each time. I don't know if this is normal or not.

 

Better make sure all the terminals are tight.

There shouldn't be any scorching going on.

 

The scorching was evident before we unpacked the batteries. Must have happened at the factory/warehouse in China.

The terminals were all fastened tightly during the install.

I bought a temperature gun on ebay today so I can make sure there aren't any hotspots.

It'll take a least a week unfortunately.

 

Tonight I drove quite a ways (54 km) to run a couple errands and again averaged around 2.5 L/100 km (~112 mpg) Still didn't drain the pack.

And this time the OEM SOC was often 7 bars full.

WHOO! HOOO!

Tomorrow we are driving from Langford to Gabriola Island just for the day, so we'll see if I can finally drain it on the way there although I doubt it since it's a highway trip.


EDIT: I have rarely seen 7 bars since. Usually 5 or 6 but even 4 bars is much more common than 7 bars.

 

I love this one....

I think we all have a skewed definition of "good" or "bad" gas mileage.

 

If you know how to knit, you can do a personalized scarf for the engine..

 

I LOL'd a bit on the inside.

 

A block heater will help a lot because the sooner you can get above 100F the sooner you can get 100MPG.

During S1 now I'm only getting around 80MPG max since the coolant temp is starting below 100F. During the summer when the coolant temp is near 100F I was getting over 100MPG during S1.

 

I have an EBH and grill blocking even though we are still well above zero here in Victoria.

 

I typically block & start using the EBH when the highs are in the mid-50's. It makes a big difference (although it is a little funny to see the outside temperature display off by so much).

 

I already have my front grills covered and my EBH connector ready for......
the tricks is "how to" maximize your fuel efficiency beside of plug-in, getting it ready and go...

 

How many miles do you drive per month? And what was your average MPG before the Plug-in mod?

 

This is in addition to charging at the end of the day for how long?

 

What would you say your average speed is while using the Enginer PHEV kit?

Andrew