One Year With Hymotion Plug-In Prius.

[TheForce]

It does not seem like that long ago my Prius was modified in the best kind of way. One year ago I had my Prius modified to be a plug-in by installing a Hymotion battery. I have learned a lot over the past year and have not had any major trouble with the extra battery. I will run through some of the stuff I have learned over the past year.

Learning how to drive all over again.
In order to get the most out of the Hymotion battery a manual EV button is a must for city drivers. Letting the Hymotion battery do all the work is OK for the average user but if you have a short commute or terrain that is hilly or unpredictable manual control of EV will get you higher MPGs.

Because I'm driving in EV mode more than using gas the coolant temperature will be colder longer and may not be optimized for EV driving. To get around this you have to fake the coolant temp. This is more for advance users that can monitor the coolant temp. If you can fake the coolant temp to above 159F you can enter EV mode and warp stealth a lot sooner.

With the combination of the manual EV button, the coolant temp hack and a good mostly low speed route I am able to achieve 300-500MPG according to my ScanGauge on my trip to work and back. If I can maintain a normal commute for the length of a tank of gas I believe I can achieve 3000-5000 miles without stopping at a gas station to fill up.

I have estimated with my CAN-View that the pack holds about 16.5Ah and on my commute I use about 12.5-13Ah. Thats about .59Ah per mile. From the wall I measure that the car uses about 250Wh per mile all electric.

You do have to be careful not to draw too many amps for long periods of time or you will start to drain the stock battery. I have found a continuous draw of 30A seems to be about the point at witch you will not draw the stock battery down but the Hymotion wont charge it either.

All electric driving on flat roads.
To sustain speeds these are the least about of amps you can draw.
MPH -- AMPS
25 -- 15
30 -- 20
35 -- 20-25
40 -- 30-35
41-50 -- 40-50
55 -- 55
55+ not really possible because 60A is the most before the engine starts to burn gas.

When the engine is on at highway speeds the car will draw about 30A and you will get about 150MPG at 55MPH.


Small issues / problems.
I have not had any major problems with the battery so far.

My battery was upgraded with the latest firmware a while back.

I have had the flashing lights a few times for a low 12v battery.

I have had flashing lights for a current sensor malfunction but that cleared its self and only happened once.

I have only had a few partial charges. I think it was due to very hot weather.

The day before Hybridfest 2009 I had my battery checked for a small manufacturing oversight. The problem was the first few batteries that were made had the fan positive and negative wiring reversed. This was a quick fix and hopefully helped the partial charging issue in hot weather.

When I had the firmware upgraded one of the wires must have come loose from the pin on the wiring harness. Instead of having to drive 100's of miles to get it fixed I soldered the wire back on to the pin and reinserted the pin back into the wire harness. That was an easy fix for me.


Mileage stats.

Total miles: 9594.6
Gas used: 75.6 gallons
Total gas cost: $181.92
Total kWh: 1380.4
Total kWh cost: $110.43
Total fuel cost: $292.35
Avg. Wh per mile: 143.87
Avg. MPG: 126.9
Avg. CPM: 3.0

Best tank
2502 Miles
299 MPG


Since its been about a year since I have done my first mileage tests I will try to perform an all electric drive and all highway drive to see if the battery capacity has changed. I will try to do these tests on my next days off that are nice and sunny.

So far I love my Prius PHEV and I don't know what I would do with out it. I will never buy a regular gas car again and I will never buy a regular hybrid again. My next car will have to be a plug-in or an all electric vehicle.

[usbseawolf2000]

Nice! 3 cents per mile for the fuel cost.

Avg. Wh per mile: 143.87

That's a lot lower than Volt's 250Wh per mile or Nissan Leaf's 240Wh per mile numbers.

I am assuming it is because the gas engine assist in some of the miles.

Do you have the average speed (MPH)?

[boxer93]

Jay I know what you mean about a year going by quickly. I actually have a hymotion service appt. On the one year anniversary of my install. I was having partial charges during a week of warmer weather. Jim at a123 wants to see the pack himself, I hope that it is the simple mis-wiring of the fan. For me I will have to calculate my annual results. 2 points for me that have helped my phev mileage is, SHM I think your thermostat hack is great. I wanted to drive mine as "normal" as possible. Second full grill block, other than driving well past the packs range on the highway, I use it all the time. Good luck on year two. I am hoping for 1500 miles for a tank. 1086 is my best tank
Chris

[zcat3]

I've had mine since November and had put 10 -12K on the car since. My best tank was 1060 miles with a 9.XX refill, so over 110 MPG. I average about 90 MPG on my round trip commute to/from San Francisco, which is almost double what I got before the Hymotion. I have done several long trips, so my overall mileage isn't anything great. Just last weekend I drove to Lake Tahoe and back and with one charge each way I got 50 MPG going up (would get maybe 40 MPG without the Hymotion) and 60 coming back down (would have average 50 or so without the Hymotion). 55 MPG average using 8 kWh total for a 500 mile R/T with a total climb of 10,000 feet or so is pretty amazing.

[Arthur]

I've had my Hymotion for over a year now, too. I just filled my tank up yesterday, exactly 90 days (and 1017 miles) since my last fill-up. I've been careful not to exceed my battery's range. So, my fill-up was only 5.9 gallons!!! That works out to be an average of over 170 mpg!!! I was careful to let the tank fill up slowly and stopped as soon as it clicked off the first time. So, that should be fairly accurate.

However, the previous fill-up was done at a temperature of 80 deg F and this fill-up was at a temp of 60 deg F. So, I should probably subtract a little to account for increased fuel-bladder contraction. Nonetheless, I still must have averaged well over 150 mpg for a 90-day period. I feel pretty good about that.

On the one hand, most of my 1017 miles were in EV mode at city speeds. That made it a lot easier to get high MPG. On the other hand, my 1017 miles includes over 60 trips up a steep hill that is over a mile and a half long. The only way I could do this and still keep up a high average MPG was to go up the hill in EV mode whenever possible. That means going between 8 mph and 20 mph for most of the hill. Fortunately, I work on a second shift and don't come home until 11 pm. So, there is usually nobody else on the road.

Considering that I DID use gas on a lot of those trips up the hill, my average MPG for the rest of the time was probably well over 200 MPG. Yeeeeehaaawww!!!!

Soon, it will be back to cold-weather driving and lower MPG. I'll definitely have to install that grill block this winter.

Arthur

[TheForce]

I ran an EV only test yesterday and here are my results.

The years results

Course same as last year.
Temp was colder.
This time it was at night with my lights on and PC running.
I did not have any problems with the SOC getting too low. I'm guessing it was because I was limiting my amp draw to 40A for acceleration and 20A to keep speed.
Speed was around 30MPH

Distance - 26.6 miles
Can-View reported 14.9Ah used
Amount of Electricity to fully charge – 4734.2Wh
Wh per mile - 178Wh


Previous year results
Actual Distance – 33 miles
Estimated Distance – 25 good easy miles. 33 miles if you work at it.
Fuel used - Technically 0
Estimated Pack Size – 18.5Ah
Amount of Electricity to fully charge – 5295.7Wh
Wh per mile - ~160Wh


You cant really draw conclusions from these tests but given that it was colder and I was driving at night with my lights on and my PC was on I can only guess that the batteries have not lost much capacity if any at all.

I will try to do a highway test on the next sunny day I have off.

I will also perform another test next year around the same time.

[ibcs]

One year ago yesterday, I had the Hymotion installed by Fitzgerald Toyota. My best tank is 1024 miles at 111.6 MPG. Unfortunatley, I drive past the range of the Hymotion many times during normal use which makes my Hymotion average for the year 65.8 MPG. I recently learned how to get better mileage when in town using the 52 MPH hack. When driving over 42 MPH the Prius stock battery is drained quickly causing a condition where the Hymotion could not catch up. In the past, once the SOC dropped below 50 the Hymotion would not recharge the Prius battery. I learned that shutting off the car and restarting with the 52 MPH hack prevents the engine start and allows the Hymotion to charge the stock battery in 2-10 minutes depending on how far the SOC dropped while driving. This allows the car to do some high speed driving for short distances and recharge without starting the engine. Since I live in town, learning this trick helps for short errands. If I had it to do over, I would definately purchase the Hymotion again. I love the ability to EV around town and when combined with the 52 MPH hack it is the perfect blend of Ev and hybrid.

[zcat3]

Originally Posted by ibcs

I love the ability to EV around town and when combined with the 52 MPH hack it is the perfect blend of Ev and hybrid.

I agree - the 2 together are a good team - but you do need to use the 52 MPH button properly and pay a lot more attention to the SOC. And of course, you have to be sure you don't accidentally hit the EV button while driving on the freeway - did that a few times.

[DaveinOlyWA]

thanks for the update. glad you are happy with your Hymotion. i echo your sentiment that i will never buy a regular car again. one way or another, it will have a plug.

[ibcs]

Originally Posted by zcat3

I agree - the 2 together are a good team - but you do need to use the 52 MPH button properly and pay a lot more attention to the SOC. And of course, you have to be sure you don't accidentally hit the EV button while driving on the freeway - did that a few times.

What happened when you pushed the button over 52 MPH. I always wondered, but I sure was not going to take a chance on purpose.

If by chance Hymotion is listening, my two wish lists would be

1) Bigger battery - I realize I have what I have
2) 220V Charging - I do a lot of errands and always go home. I could plug to 220v and charge so much faster.


---Kent