Hymotion Problems? Users Feedback Please.

1. The 12v issue should have been fix with one of the firmware updates. I personally dont know since I have installed a 12v battery charger in line with the Hymotion power inlet.

2. I cant comment on this as my setup is different. I have an EV button that allows me to manually enter EV mode. My Hymotion battery does not have any control over EV mode.

3. I dont know of any battery performance updates but the firmware has fixed some other small issues like keeping the reverse camera on when in reverse.

4. I've only had 1 major issue that happened in July of this year. The DC to DC converter quit working. The battery was still under warranty so the dealer did a pack swap.

I've had mine for 3 years and I think it is worth it.

 

I have had the Hymotion battery in my 2008 since last NOV. TheForce answered most of your questions, but I will answer about the chirp. For a long time I couldn't figure out what the heck it was, but I think it is just the Hymotion "fighting" with the car's regular hybrid logic as to whether or not the engine should be on or off. It happens around 35mph, and only under certain acceleration conditions, when you are accelerating at slightly below a "moderate" rate. I wish I could describe it more accurately. Anyway, the car kind of hesitates and it fees like the engine "missed" but to me it is not a big deal now that I know what it is.

If my wife did not drive the car and I did not have to drive beyond the range of the battery, I'd be easily getting over 100mpg. Unfortunately, real world with the wife not caring about MP G's, driving about 30% of the time beyond the range of the pack, I'd say the Hymotion pack adds about 20mpg to my average.

With the plugin Prius coming out, I am not sure I would drop 11K into the Hymotion pack, but that's pretty subjective of course.

 

I have had the Hymotion kit installed for several months. It is almost as if nothing was changed. My best tank was 65, but mostly in the high 40's. If EV mode is non-existent past 34 mph, am I required to average 25 mph to obtain >100 mpg? If so this was never disclosed to me prior to the purchase, nor is it evident in any sales literature. I have already become a traffic hazard trying to stay in EV mode (<34mph).

At this point I consider it a near complete waste of money. Fortunately Colorado offers a $6k tax credit, so I only have to eat $4k.

 

MaxOrbit how far do you drive? Do you drive on flat or hilly terrain?

The reason I ask is that you should be getting 100+ on anything less than about a 30-40 mile trip.

Does your state of charge show green after a full charge? How many miles does it take for battery to run out?

To get 100+ MPG you dont have to be in EV mode all the time.

 

Max-

That doesn't sound right at all. I wonder if there is something wrong with your pack. I mean, if I just cruise down a flat highway with the cruise control at 65mph I'm getting at least 75mpg++.

I would think that where I live is probably one of the worst driving conditions for mpg, where I have a stoplight every mile or two and in between the lights you basically have to accelerate to 45-55mph or so in order to keep up with the flow of traffic. So it's stop and go, stop and go, stop and go for me.

There is definitely "technique" required to use the pack effectively I think. For example, if I'm cruising down a flat road at 50mph, I "lift off" the gas to get the engine to shut down, then press lightly back on the accelerator so just the battery is now driving the car and I am maintaining speed. You don't have to be below 34mph to be driven largely by the pack. I use the display that shows the yellow bars and if I see the yellow bar drop down to 50mpg or less, I know the engine came back on so I accelerate back to the desired speed (if necessary), lift off the accelerator, then press lightly down again to maintain speed. After awhile, you can just feel it so it is not so mechanical.

My drive to work involves 15 minutes of the stop and go mentioned above, 15 minutes of highway driving at around 65mph, and 15 minutes of divided highway with stop and go every few miles at around 40mph. The terrain is relatively flat, with some slight hills. My yellow bar mpg indicator is routinely completely filled with yellow bars on this route, depicting over 100mpg for about 40 minutes.

Again, either you have really weird driving conditions where you are (highly mountainous terrain?) or something isn't right. Is there anyone out there in CO that you know that has a Hymotion pack that you could try out to see if it is behaving differently than yours?

 

I have thought about trying to find another Hymotion user.

I live in the Denver metro area and my driving is relatively flat, certainly not mountainous. I am an engineer and I do understand what I have and how to work it so I know what you're saying. I have a very difficult time getting into and maintaining EV mode. I do watch to see when the ICE runs and I get frustrated because it runs when I think it shouldn't. I do know that the engine needs to be kept at normal operating temp so it will kick on occasionally to maintain that. I have taken it back to the installer twice and both times they seemed to think nothing was wrong with the system, I just needed to learn to drive differently.

One thing that frustrates me is that when I do get into EV mode I cannot set the cruise control to 32. If I get above 35mph, the ICE kicks in, guaranteed.

Another is that driving this otherwise delightful car has now become a video game, a distraction. I put 40k miles on it before the Hymotion kit.

I am hoping that some from A123 can help me. I am going to track them down next.

 

I drive about 35 miles round trip into Denver, relatively flat city driving. I have 100% SOC when I leave and maybe 60-75% when I return. I agree that I should be getting more boost from the pack at speeds above 35, but I don't sense that happening.

BTW, we have 6.5Kw of PV panels on our roof. (yes, I have a solar powered car) Could I have an incompatible electrical format problem? :lol:

 

My cruise control won't set that low unfortunately, either. Yes, the ICE kicks in above 34mph, but I can still get 99mpg+ with the ICE "on" in the little diagram on the screen. I don't know what is going on mechanically (TheForce and others know better than I), but perhaps it is "on" in the sense that it is spinning but receiving little if any fuel.

Also, at high speeds, sometimes I can't get the ICE to shut off at all no matter how lightly I press the gas. In that case, my mileage takes a hit, but I'm still getting around 75mpg when there is energy available in the pack.

Yes, you're definitely right about it being sort of a "game" while driving. I don't think the pack is for someone who just wants to turn the car on and drive. My wife, who could care less about maximizing mileage and utilizes NO technique whatsoever, regularly trashes my mileage on the pack, so I imagine she isn't doing much better than maybe a 5 to 10mpg gain when she drives. There is certainly driving technique involved.

My advice would be that when you see the engine kick on, and you're at a steady state speed on relatively level terrain, lift your foot off the gas, then press lightly back down to try to maintain speed. That is what works for me and gets me 100mpg+ while cruising at constant speed. If you think there is something wrong with the pack, I would perhaps find a long, flat stretch of highway, set the cruise to 55mph, and see what kind of mpg's you get. You should be getting at least 75mpg, and likely over 100mpg's on average.

I'd come out and drive yours to see if it was different than mine, but unfortunately I live a long ways away and I am certainly no expert in the operation of the pack!

Worst case scenario is that you only paid 4K for the pack. If you sold the car with the Hymotion pack in it, I would venture to guess that you could certainly recoup your costs and perhaps use the proceeds to buy a plug-in Prius with a similarly sized pack that requires no "gaming" while driving

 

On a 35 mile round trip you should be seeing about 100MPG or more unless your driving it hard. Plus if your getting 100+ on a 35 mile trip you should be using up all of the battery and not have 60-75% still remaining. Something tells me there is something wrong with the battery if thats the case. Even driving it hard you should be down to at least 25% remaining. Wish I was closer to you so I could see it for myself.

 

I don't know what the lower limit of the cruise control for the 2008 is, Hymotion installed or not. I do know know that I cannot get it to engage at 34mph.

 

25 MPH is the minimum for the 2004-2009 Prius. I know for a fact my cruise control works at 35 MPH but I never really needed it below that. I will try the next time I drive my Prius.

Make sure your not driving in B as that will cancel the cruise control.

 

Hi Max. I live in the Denver area and had Pro Auto Care install my A123 pack. I've experimented with driving techniques to increase the time the car stays in electric only mode with not much success. I think a lot of that is due to engine temperature and the flatness of the road you're on as well as the speed range you can maintain. I have been happy with the mileage increase. Minimum I get 65 MPG and that's on a highway commute with lots of hills. I can get over 100 when driving from south of Denver to downtown. I had hoped to get over 100+ for all my driving, but found I had to adjust my expectations. However, going from a 4Runner that got 20 MPH to a Prius that gets at least 65 is a pretty good improvement.

 

I've tried to get an answer to the chirps without much success. The "fighting" theory between systems is correct. Recently I think through observation I found what may be the answer. The chirps seem to come when the Hy pack is at least 4 bars and the Prius battery is in the green bar zone. I think what's going on is that when the battery is green and the Hy pack tries to keep feeding electrons to it, it resists by giving the chirp warning. What I've been doing is turn off the Hy pack when I see the Prius battery is green and use it untill it goes down at least to 4 blue bars. I haven't had any issues with turning off the Hy pack while driving even though the owners manual warns against it.

 

2. I cant comment on this as my setup is different. I have an EV button that allows me to manually enter EV mode. My Hymotion battery does not have any control over EV mode.

I'm curious about installing the manual EV mode button. How difficult is it? I don't want to pay someone to do it, but I don't want to screw up my car by installing it. What's your recommendation?

 

I tried today to get cruise control to work below 35 and it worked for me.

 

You have an EV button but you want to install a manual EV mode button?

 

That's weird. I just tried again today to get my cruise control to engage at 34mph on the way home and it wouldn't take. It won't stay on until I hit the low 40's. I have an '08.

 

Have you tried cruise control with the Hymotion pack turned off? The reason I as is that maybe EV mode cancels cruise control? I'm driving my Insight tomorrow so I wont get a chance to try it out.