Hymotion L5 PHEV Prius Review
After arriving at Fitzgerald Toyota I met Gil Briggs and Ed McCurry and went over some of the details. After talking with them I was able to drive the car down to and into the service area. There I met Matt the Prius tech. He will be doing the install of the Hymotion battery. While I was there he was able to get part of the rear seats out before I could even get my camera ready. After getting a few pictures Matt wanted to work on the wiring so I went up stairs to the waiting area. The wiring was going to take a few hours so I was able to surf the internet for a while and head out to lunch. For lunch I went to the Flaming Pit which was just a quick walk down the block from the service center. It’s a bar and grill and they have very good food and the waitress was very very very cute.
After arriving back to the service center I had to wait about 30 minutes before they were ready to install the battery. After the battery was lowered into the car there was nothing much to do but wait. I decided to leave the car there over night so they could charge it and test it. They gave me a free rental car because it’s covered under their contract to have free rentals when you have your car worked on. I was given a Nissan Versa. I hated it. Nuff said.
Next day I arrived and they had the car ready to go at about 7:30am. Matt told me they blew a breaker last night and the pack did not have a full charge but I should get a few miles out of it. I finished up the paper work, installed my wheel skirts, computer and I tried to start the car. Nothing happened. Smart key was disabled. So I enabled it and tried to start again and again nothing happened. So I inserted the key in the slot and the car started fine. I turned it off and removed the key and tried to start again. It started fine with the key in my pocket. I guess once the smart key system is turned off and battery unplugged the SKS need to be initialized once with the key in the slot.
So everything working fine I set a destination to McDonalds. On the way there I watched the normal flicker of the SOC display indicating the SOC of the Hymotion battery and the stock battery. This will take a little getting used to but there is an annoyance that I think is more of a bigger issue. When ever you are on the navigation screen and have the battery turned on it will switch back over to the energy monitor. This could happen on other screens as well. The only solution is to turn off the battery while you need to use navigation or other screens.
On the way home I got on the highway and I was seeing 100+MPG at 65MPH for about 10 or so miles before the pack turned off. This is all the experience I have with the pack so far.
Over all Fitzgerald Toyota was very professional and very kind. They make you feel at home. Their service center was huge and had a little bit of everything. It was very neat and clean. I’m glad they were the ones installing my battery.
According to my receipt here is the total cost.
Total out of pocket including deposit... $10971.00
Here is the battery.
Here is the contents of the parts box.
Here is the side view of the battery where the high voltage lines come out.
Here is the wide shot of the stock battery.
Here is what the car looks like naked from the inside.
Close up of the battery ECU area.
Someone is a little curious of what’s happening on the other side of the service area.
Wiring for the switch and ECU.
Matt was able to place my switch above the "blanks" for me as I have all of my "blanks" filled up with buttons.
Matt installing the battery
Sticker on the side
So what do you get in the welcome kit?
Inside the envelope there is an updated instruction manual, a quick start guide that looks like it can hang on your rear view mirror, a square 100+MPG sticker that looks like it will fit on the gas door, a Hymotion window sticker, an oval PHEV sticker and a Hymotion logo "H" keyring.
Storage, Charging, and observations.
Here is something interesting I found on the left hand side. It looks like a serial cable. It only has three wires that I can see. My guess is that it’s for updating the firmware or monitoring the battery. It would be nice to find out what it actually does.
Here is the view of the wires.
I have tested to see if it sends any information to my serial port on my computer but I did not see any information with the pack turned on or off. My guess would be that in order to get information from this connector you need to send it a request or this may just be for programming. It might be something like a JTAG.
As far as storage goes there is not much room for anything but with a little creativity I was able to fit almost all my crap back into the storage area. I should note that you should not block the airflow to the under side of the battery. The way I have my stuff laid out it should not block airflow but you have been warned.
Here you can see there is a big space on the right hand side. Below the air duct there is a large gap where you can store stuff but it’s a tight fit to put things down there. I think the small gap below the battery is where the air intake is for the battery so you don't want to block it with a bunch of crap.
There is not much room on the left hand side either because the exhaust duct.
What I did with the jack was to wrap it in a towel.
All wrapped up.
And I stuffed it partially below and in between the air duct. It fits nicely here and won’t rattle around.
My ice chipper and snow brush fits nicely here.
I wrapped up the crank / tow eye, and the lug remover. I fed the crank through the tow eye to keep them together.
This is how a warped the crank and tow eye. I then lowered the crank in between the air duct and battery casing and the whole thing rests on top of the air duct. The lug remover fit nicely in between the stock battery and the Hymotion battery on the right hand side. You can see the towel in the upper right.
Here is where the crank/tow eye fit.
I was able to pack a few towels in the left and I was able to fit my keyboard, and air compressor in this area.
I also wrapped up some cans of deicing for winter.
Everything hides away.
All except the spare tire.
I will remove the spare tire and carry a tire patch kit when I need the extra room in the trunk. Since I hardly ever carry a lot of stuff I will keep the tire in the back. If I need to carry something large I can either use the back seat or move the tire to the back seat if needed.
Charging the pack seems to take about 5-6 hours. After charging it seems that the battery still draws about 22 watts and about .3 amps. My first observation on this lasted about 12 hours and when I was looking at the battery I heard a fan. So I think the fan is just cooling the batteries and the cooling period takes about 12 hours in the summer heat. In colder temperatures the cooling only lasts a few hours.
I'm using a Watts Up? .Net meter to track my usage. Info about this product can be found here. http://www.wattsupmeters.com
Here is a graph of the watts used over time. This was my first charge from a depleted pack. The charge area is a period of about 11-12 hours. As you can see it spikes up to a little over 1kw then drops to about 900w to top off the batteries. Then it will linger around 22w with a few high spikes to cool the batteries.
Here is a better graph of the charging process from a depleted pack. The first two hours the pack sucks down a little over 1000 watts and about 10 amps. Then the next three and a half hours it will suck down about 950 watts and 8.5 amps. Then the rest of the time it will suck down about 22.5 watts and .26 amps for cooling down the batteries. Once the cool down period is finished the amp draw is 0 according to my watts up? meter but it still shows about 3.5 watts being drawn.
These two graphs represent about 12 hours of time.
Charging the pack is very simple. Just plug it in and wait. The brake lights will come on to let you know you plugged it in and will dim to about %30 until the battery is fully charged then they turn off letting you know charging is complete. Here is a video of the charging in action.
I have noticed that when the Hymotion battery runs down to the blue bars the stock SOC will go all green sometimes but the stock battery holds a %60 charge. It’s kind of hard to tell the difference between the stock SOC and the Hymotion SOC sometimes but once you drive with the battery installed you get used to which one of the flickers is your Hymotion SOC and which one is your stock battery SOC. You can always disable the battery for a few seconds to get a view of the stock SOC. Sometimes when the pack is turned on and your on a different screen like the navigation screen it will not flip back to the energy screen. I have not determined when it will flip back to the energy screen and when it does not. It may have something to do with the SOC.
Here is a video of the SOC flicker.
I have also noted that with the engine being off more I may have to go with a year around grille block to keep the engine warm in city driving or do an coolant temp hack to keep the coolant temp around 160F. This way I can get into warp stealth sooner as well as get into a glide sooner. This type of hack will also let the car stay in full hybrid mode for longer periods of time when driving in the city.
I have installed a variable resistor and a switch to do the coolant hack and I can say it does help a lot but at this point I cannot recommend doing the hack. From my experience so far although the hack works to keep the Prius in full hybrid mode it does cause some error codes to be tripped and the check engine light to turn on. I have also experienced that if you have the temperature set too high when you first start the car the engine will start out very rough and almost die. This can be an issue when first starting the car if you not careful. Clearing the codes are not a problem as long as you have a CAN-View or a ScanGauge to clear them.
It looks like if the stock Prius battery is around %59-%60 The Hymotion battery will keep the stock battery charged. If the SOC is below %59 it will not charge the stock battery unless the car is in motion. More testing is needed to see what is really going on.
The ScanGauge may not be accurate to calculate fuel mileage because when in EV mode it still reports .01 GPH of fuel being burned. When getting numbers as high as 500MPG on a trip just sitting still for a few seconds will make it drop a few MPG. Even when in EV mode while moving it may not get very high very fast because of this. For an example if you driving down the road and the SG said 250MPG you might be closer to 275MPG or something.
When the Hymotion battery starts to get down to the last 4Ah it starts to lower its spoofed SOC. While it’s lowering its SOC the stock Prius battery is also draining. For an example if the Hymotion battery is reporting %70 SOC then the Prius battery has about %60. If the Hymotion battery is reporting %65 SOC then the Prius battery would be at about %%55. If your in EV mode this can go as far down as %40 before the Prius kicks on the engine to recharge its stock battery. More testing is needed to really see what’s going on here.
Here is a graph of the reported SOC from my CAN-view. Data is captured about once every two seconds or so. This graph represents my whole 22 mile round trip commute.
Here is a graph of the CAN-View reported SOC on a 60 mile round trip. I started the trip with the pack off because I wanted to use most of it on the highway. Then I turned it on until I got into the city then turned it off to do some P&G. Then turned it back on to go back home. Then the pack depleted and turned off the rest of the trip. My CAN-View said I used about 16.5Ah.
Inverter temperature would be something you might have to keep an eye on if you do a lot of all electric driving. From what I have seen I don’t think it would be much of an issue because according to my CAN-View the max invert temperature was around 175.
Since the ICE is used less in the city and under very small load on the highway my guess would be that I can have longer oil change intervals. Since I only had about 2500 PHEV miles out of the 5000 miles on my oil change this time it’s hard to tell if I can go farther. According to my oil analysis my previous TBN’s were around 2.7 to 3. This last oil change it was 4.4. As soon and I get my analysis from my next oil change I will let you know if I can go farther or not.
Driving with the pack.
My normal commute to work is about 11 miles one way or about 22 miles round trip. Most of my commute ( about %60 ) is 55mph speeds or slower when no one is behind me. Then the next %40 is all city driving. So according to the data from Hymotion I should be within the 30-40 mile range of the pack especially if I hypermile the heck out of it. I will always travel at the speed limit and not 1 MPH higher if someone is behind me. If weather conditions prevent me from traveling at the speed limit I will always travel at a safe speed.
Here is my elevation profile for my commute to work. I was able to get the data from my hand held GPS and import it into a spread sheet to get the graphs. It was a little more accurate than the profiles you can create online. I still don't think it represents the actual elevation changes I encounter but its close enough. Since the roads here are next to hills the data that’s available online makes it look like I'm driving up and down mountains when in reality there are only a few minor elevation changes on my commute to work. The first 500 or so feet I can EV it out to the main road. Then its 55mph all the way to about mile 6.5 then it drops to 35 or below until I get to work. This profile elevation scale is not at sea level. Just add 500 feet to the scale and you will get the above sea level numbers.
Here is a video of my round trip commute. The start of my commute to work is a little bit down hill. Then about 3 miles down the road there is a hill I have to climb. Once I get on the highway there is an overpass I have to climb and about .5 miles before I get to work I have to climb another small hill. Then reverse that on my way back home. In between the larger hills there are a few places that go up hill but don’t really affect my speed or MPG much.
For my first commute to work I decided not to use my EV button or any hypermiling tricks to see what kind of normal MPG I could expect. The only thing I used to improve MPG was my block heater. I stayed at or below the speed limit when possible. I mostly tried to stay at the speed limit. On my trip to work I pull in the parking lot with my ScanGauge showing 114MPG and 4 of my 5 minute bars were maxed out. The first bar was very low because I was setting up my computer to record some data. Normally when I just take off with my engine warm from the EBH I get over 50MPG the first 5min. On my way home my ScanGauge showed 118MPG. I still had plenty of charge left so I might try to use a little more EV mode if I can.
To work SG
To work MFD
From work SG
From work MFD
Day two I was able to pull 137MPG and from what I learned from the pack I should have plenty of room for higher numbers. I should be able to do my entire city driving in EV mode and still have plenty of power for the highway in warp stealth on my normal commute. I was able to drive from work to a car show all on EV. I switch to EV when I started and did not let the car warm up. The total trip was about 5 miles. I did not get any good numbers for my trip home because I was playing with a few things and I forgot my pack was turned off. I was in EV mode and I drained the stock battery by accident.
I still managed to pull about 90MPG though and had plenty to get a good 100+MPG even with that 5 mile EV only section.
Day three on my way to work I tried a little harder to keep the engine off and achieved 236MPG and I still have room for improvement. I started out in EV mode until I hit my 55mph road. Once on the road I got up to about 45 and tried to do a glide. The engine was still a little cold so I did not get into any kind of good glide but still better numbers than trying to keep speed. Once out on the highway the engine was warm enough and I was in warp stealth. I was drawing about 50A off the battery and holding 55 for the short distance to the overpass. Once getting to the overpass I had to use a little gas to keep from losing too much speed. Once at the top of the over pass it was all EV to the parking lot at work. I’m able to do that because after you come down off the overpass the speed drops to 50mph, then a short distance later it drops to 35mph, Then drops to 25mph, then raises to 35mph. Normally I could not hold a warp stealth from the top of the overpass to the 35mph zone but with this extra pack I can almost hold it forever.
On my way home I was able to pull out 195MPG.
Day four I pulled into the parking lot at work with 237 on the ScanGauge. I took a little detour to see if staying in EV mode a little longer would improve my MPG before getting on the highway. It looks like it will not help. On my way home I was lucky enough to not have anyone behind me and I was able to do 30MPH almost the way home. Someone got behind my on my last mile and I had to speed up. If it was not for that I could have had a 1000+MPG trip home. I pulled in the driveway with 516MPG.
176MPG over 80 miles
. Please note that my average speed includes time spent at stop lights and stop signs. Remember that if someone speeds at 80mph down the road they will still have a low average speed if part of the trip is traveled through a city.
All but one of the 30 miles is three digits!!
So far the car acts very different when the pack is enabled and certain hypermiling techniques need to be modified for best results with the pack. For an example during highway driving you can draw about 40-50 amps at 55mph in warp stealth and you can hold 55mph and even accelerate using no gas. You can do this or let the engine run and get 150+MPG and the battery will last longer. It really all depends on how far you have to travel on the highway and how much you want to use the battery. Do you want to use it all up on the highway or do you want to EV around the city? Or do you want to do a little of both? I think the best way to use this pack if you have a lot of highway is to get 150+MPG on the highway for as long as possible. Then if you have some city driving you can always pulse and glide your way to work or home. Since my round trip commute is about 22 miles I'm well within the range of the pack and I can use as much EV mode and Warp Stealth as possible.
It appears that the Hymotion battery quits spoofing the SOC so the stock pack can capture any regen. Normally when the pack is turned on it will spoof about %80 SOC but if you let off the go pedal or apply the brakes it will stop spoofing to allow the car to think it still has room for the extra energy. The normal SOC stays around %60-%63 when the pack is turn on.
Because of the way the battery works with the Prius you may have some trouble getting over 100MPG in city driving especially during the colder months. The coolant temp must be 70c to enter normal hybrid operation. Since the engine must run to get the temp that high you will enter and exit electric mode during city driving because the engine is off and the coolant is cooling down. Once it gets below 70c the engine will want turn on and warm bake up. The only way around this is to fake the coolant temp which at this point I don't recommend anyone trying unless you have a ScanGauge or CAN-View to clear the error codes you may get. The only real solution is to use an EV button to manually enter EV when below 34mph and if possible stay below 34mph in the city. If your traveling mostly on the highway then this issue will not be a problem since the engine must spin when above 41mph.
Unofficial official testing.
Let me say this first. I was estimating on 10-15 miles in all EV mode based on the Kwh used in the official testing and the 30-40 mile official estimated range in highway mode driving. All I can say is that I'm just completely blown away with the results below.
For my highway test I started my stock SOC at %60 and I set cruise control to 55MPH. The Hymotion pack had a full charge and I did not turn it on until I set my cruise control, reset the trip B and reset my trip on my ScanGauge. The AC was off too. Once everything was set I turned on the pack. I used route 52 from Wheelersburg Ohio to about South Point Ohio where I turned around. I tried making elevation profiles but since the highway was next to the hills it looked like I was climbing 200 feet when I was actually on pretty level terrain with only slight elevation changes. Before I get to my results I have to tell you that about %75 of the trip was at 55MPH, %20 was at 45MPH or less due to construction and %5 was at a dead stop due to construction. Because of this and the GPH bug in the ScanGauge my total MPG at the end of the trip was a little low.
The first 40 miles the pack was able to keep the car going at 100+MPG. When I reached the 40 mile mark the next 10 miles was 70+MPG. The pack quit with 50.7 miles showing on the trip B. If you recalculate it by taking out the construction zone and a little stop and go driving I believe I can estimate a total distance of about 55 miles with cruise control. My ScanGauge showed 101MPG but I can estimate it more in the 125MPG area because of the GPH bug. According to my CAN-View the pack Ah size was about 17.5Ah.
So let’s review highway with cruise control set at 55mph.
Actual Distance – 50.7
Estimated Distance - 55 miles
Actual MPG According to SG – 101MPG
Estimated MPG Because of SGII GPH Bug - ~125MPG
Estimated Pack Size – 17.5Ah
Amount of Electricity to fully charge – 5541.2Wh
Highway speeds round 2.
This was not really a test but more of a normal drive. For this “test” I had cruse control set at 55mph, AC set on 72 degrees, fan on low, one passenger and six 16lbs bowling balls. The battery lasted about 30 miles. About 4 of those miles were below 35mph in the city. For those 30 miles the average was about 150MPG but I don't know the exact number. My total trip for this run was about 65 miles. My average MPG for this trip was around 85MPG. I have my CAN-View set to count down the Ah from 17.5Ah and when the pack gave out the number on the CAN-View showed about 0.3Ah remaining. So the pack should have around 17Ah of usable energy when fully charged according to my CAN-View.
City all EV mode.
For this test I started my SOC out at %60, reset my trip B, and enabled EV mode. I ran this test with no AC but had front driver side and rear passenger side windows cracked. I limited my amps to about 50-60 when accelerating. I tried to stay around 32MPH with a constant draw of about 20 amps to keep speed. I tried not to pulse and glide but I did try to time the lights so I could keep my stopping to a minimum. This test was done around the city of Portsmouth and New Boston Ohio. Terrain was relatively flat since all the roads are near the Ohio river. If you want to know the elevation profile of the route just look at my commute elevation profile ( located above ) between mile 6 and mile 10. This will be very accurate as there were no hills in the city that I had to ascent or decent.
The first 25 miles was all easy EV mode. The engine did not come on at all. Right after about 25 miles EV mode canceled and the engine started. Apparently the stock SOC dropped to %45 and canceled EV mode. I think this is a side effect of how the Hymotion battery works. I pulled over in a parking lot and put the car in park. I watched as the SOC slowly climbed to %50, %55, and then %60. I then took off again in EV mode. I watched as the SOC dropped again to about %50. I pulled over again and let the SOC come back up. I did this a total of three times between mile 25 and 33. Once I reached about 33 miles the Hymotion pack gave up. The CAN-view was showing I used about 18.5Ah
So let’s review city driving with EV mode only.
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
First fill up and conclusion
October 11, 2008. Today is the first time I have put gas in my Prius since August 13, 2008. That was 59 days and 1275 miles ago. According to my CAN-view I had about %25 of my fuel remaining and could have traveled another 500 miles but I had to fill up for a tip I’m taking to Cincinnati.
I have not had any major problems so far other than the pack would not turn on for some reason but after it sat there for a while it started working fine again. I also had a few partial charges with the pack but I believe that was due to the heat. Since the temperature has dropped I have not had any partial charges.
I would like to note that my Hymotion battery does not enter EV mode on its own. My installer seen that I have a manual EV button in my dash and did not install the auto EV feature for the Hymotion battery. So your experience with the battery may be different than mine. I find that having manual control of EV mode is better in some situations than letting the Hymotion battery try and judge when it is best.
Now here are some numbers for you.
7.862 Gallons of gas
3.3 cents per mile @ 3.199 gas and 8 cents per kWh
Now let’s take the same price for gas and compare it with other MPG numbers.
60MPG = 5.3 Cents per mile - Good Prius driver
45MPG = 7.1 Cents per mile - Average Prius driver
25MPG = 12.8 Cents per mile – My previous car
21MPG = 15.2 Cents per mile – Average car
You could say that all this is equal to buying gas at $X.XX which might get people to understand what the true cost is. For an example if you take my 3.3 cents per mile and compare it to what I was averaging with my Prius which was 60MPG then that would equal out to about $1.98 per gallon of gas. Or you could compare it to the average driver of 21MPG and I would be paying about $0.69 a gallon.
Now for those of you that worry about breaking even here is a short list for you.
500,000 miles if you compare it to my regular Prius average
236,000 miles if you compare it to the average Prius driver
105,000 miles if you compare it to my previous car
84,000 miles if you compare it to the average car
For me it’s really not about braking even. It’s about using less gas and giving more money to American companies by buying an American made product and American made electricity. The more electricity I can use the less money other countries get when I eventually have to buy gas.
I have come to the conclusion that this extra battery will really only benefit someone that commutes about 10-15 miles to work city or 30-50 miles highway. If you can plug in at work you can double those numbers. If your commute is within these numbers then your all most guaranteed to get over 100MPG. Even if your commute is longer you can expect to get 70, 80, or 90 MPG average. The only question is will it be worth it? For me it will still be a YES.
Here are a few items that I would like to see included in the price of the Hymotion battery.
1. An extension cord. This should be obvious.
2. A tire repair kit. A plug kit or one of those fix a flat in a can. Both of those are cheap to purchase.
These items should be available to the customer as an additional purchase or just thrown in for free.
1. Some kind of power meter to track power usage when charging. Something like a Kill-a-watt or a Watts Up? Meter.
2. Engine block heater. This is a must have if you want to save more fuel.
3. Manual EV button for the advanced drivers out there.
4. A good timer for those that use net metering.
Q. Does this void the factory warranty?
A. No it should not. Hymotion gives you a 3 year warranty and with that warranty they say that if Toyota would deny you a warranty repair because of the Hymotion battery they would cover the cost of the repair. For more info about the warranty visit Hymotion :: Enabling the new generation of hybrid owners to maximize their fuel efficiency
Q. Who is doing the install?
A. Fitzgerald Toyota in Gaithersburg MD.
Q. Is this a private or fleet conversion?
A. This is my own personal conversion.
Q. Does the install/upgrade come with tire repair kit?
Q. What does the dash button and light do?
A. The button lets you turn the pack on or off. The light I think just lets you know there is juice in the pack and it can be used.
Q. Can you disable the system and if so what type of steps are required to use the supplemental battery (just unplug and go)?
A. Just turn the switch to the off position and the Prius will go back to normal operation.
Q. Is the charger for the batteries attached to the bottom of the unit (filling the spare tire area)?
Q. Did it come with an owners manual, if so, could you scan and attach it to your next post?
A. Yes it did and here it is. http://stuff.jaygroh.com/priuschat/b...uide%20V03.pdf
Q. How do you know the SOC on the L5 battery pack?
A. It "updates" the current SOC on the energy monitor by quickly flashing it between the normal Prius SOC and the Hymotion battery SOC.
Q. Does the vehicle sag from the additional weight, if so, do you plan to compensate for the additional weight?
A. I think it does but I never measured it before I had the battery installed. It cant be much. Easy way to find out is to find a 200lbs friend and have him sit in the trunk and measure how far down the car goes.
Q. How many charges is the battery good for?
A. I read somewhere that it should be good for at least 3500 charge / discharge cycles. For me it would be 1 charge a day about 6 days a week for my commute and maybe another trip or two. It should last me 10 years. I hope.