Is hypermiling killing the battery?

Ha! Hysteresis is a funny thing it applies to life as well as electronics. Resistance to a change in state. From when a lightbulb decides to lite from a dimmer switch or my wife gets me to put down my beer and fix something that needs fixing. Like the water heater I just finished installing.

 

While you guys keep arguing im just going to enjoy my car lol......... personally when I come home and see that I am using 3-4 l/100km or 60-70mpg.... I know using EV mode is working for me =).

If I have to replace the batteries in 6 years... welp covered by warranty =P

 

Perhaps...
You might also consider that while your fuel economy is quite nice, I exceed it -- without stressing the battery.

People like you are the reason I avoid buying a used Prius.

 

I'm still thoroughly confused as to how to drive the thing. The more I read the more confused I get. As long as an ICE isn't being lugged up hills at low rpm's with the pedal to the floor there shouldn't be any harm in driving one less moderately than normal. After all, like The Car Talk guys always say, "it's the total number of rpm's and not miles that wear out an ICE". Why even have an electric drive system in a car if it's detrimental to use it? If I'm on a flat surface or decline I try to start off in EV till I get to between 5 and 15 mph, depending on traffic circumstances, before letting the ICE take over. I can't see any damage incurred in a battery that stays in between +-40% to 80% charged. When I do glide I go into EV for a short time to stretch it before letting the ICE take over toward the end. I always motor in my neighborhood the last mile or 2 on EV. Same with the last mile or so getting to work. I also EV in parking lots. I have read so much stuff that says its good for pulling the car in and out of the garage but not to use it otherwise. Once again, I am confused to the point of wondering if the car would be just as efficient with only the ICE and it being able to shut off at stop signs, traffic lights, and gliding. I just drive 220 miles round trip with my son this afternoon to buy fireworks. As soon as I hit the on ramp I reset trip B. The fireworks store was right off the exit 110 miles away and straight back on coming home. I averaged almost 60mpg at the end of both stops and that was all ICE with CC and my A/C blasting the whole trip. The most I did was disengage CC and glide down at the end of rolling inclines then re-engage CC. Someone please tell us EXACTLY how a prius is supposed to be driven. I didn't buy a car to have to buy other wireless gadgets required not to damage the thing.

 

Driving a Prius like any other car driven for fuel economy will give you a very respectable 60 mpg.

1. Slow down on the highway
2. Coast to turns and red lights
3. Anticipate traffic
4. Minimize brake use

For better fuel economy into the 70s you have to P&G and use regen rather than friction brakes.

That's it.

 

Well, at least we can agree on these four points. Also, if you want to pulse and glide to maximize your mileage, good for you. However, I live in the real world where there's traffic. I doubt I'd P&G even if there wasn't.

As far as "wearing out the battery" is concerned, I think it's a silly argument. Even when the ICE is running, there is a good chance the battery is either charging or assisting the ICE. So, just because EV is off doesn't mean the battery isn't being used. (Don't take my word for it; there is a display available that will show you how active the battery is at any given time.)

Common sense driving (i.e, the four points above) and using common sense concerning the advice you get on this forum. In other words, much of the advice is good; however, use common sense to determine which qualifies as good advice! For example, if someone tells me EV mode (automatic EV mode, not when you pushed the button) is bad for mileage and bad for the battery, I choose to dismiss it. Now maybe they are right and I'm wrong, but my real world experience and common sense suggest otherwise.

 

I take it you think anybody who uses P&G lives in a 'fake' world ?

Try to not be so inflexible in your thinking. I P&G all the time in city driving. I just avoid going over 45 mph, and I stay above 38 mph out of consideration of other drivers and so that my time to get to my destination is not prolonged.

Addendum: Non-irritating to other drivers P&G is harder for Prius 'c' drivers because the EV threshold is ~ 42 mph. Still, from red light to red light a driver can accelerate up to 42 mph and glide for most of the distance to the light.

 

I live in Atlanta where P&G is an excuse for someone to "stand their ground". Thanks to our Governor you can open carry in a kindergarten as well as a bar so I tend to stay under the radar of everyone around me now in a motor vehicle and just stay home when I get there (Kathy, the owner of my neighborhood "watering hole" is probably wondering why I dropped off the face of the earth). When I do get in a more rural setting my P&G consists of a glide down hill with the bar below ECO, the EV indicator on and the mileage pip at 100. Getting all arrows to disappear is way too much work. I would be a nervous wreck after driving 10 miles going up to 45 and down to 35 over and over again. I know, I tried that the first couple of months I had mine and was wondering if I made a mistake not getting the hybrid Civic instead. I'll take my 50+ mpg and drive it like the 4 suggestions mentioned earlier. My bro in law is a PhD psychologist who always says, "happiness is being happy with what you've got and not always trying to get more". It's not worth it, to me, to be greedy about it.

 

Open carry wouldn't have changed for you while driving... you were always allowed to do that in Georgia. Unless of course you are now driving your car into bars and elementary schools. But this is more fear of the unknown and a completely different argument.

 

Remember that this is mostly a game to see who can get the best mileage. If you will be going broke unless you get 70mpg, maybe you should get a bicycle. You cannot maximize the mileage without using pulse and glide, and you don't have to impede traffic doing it. You can pulse and glide at 75mph as easily as at 35mph....you just won't get the really good mileage. It is easy to do and becomes a natural driving style after a while. You are constantly charging and discharging the battery regardless of how you drive. Without an OBD reader, it is hard to see what is happening with the battery and engine. I am about 150 miles into this tank and am getting a bit over 71mpg. I avoid using the battery to accelerate, but always stay in the bottom half of the ECO side of the power indicator when accelerating.

 

P&G means Pulse & Glide. You are not gliding at 75 mph. You can Pulse and Coast, but that is less efficient than just running the ICE with fuel all the time at ~ 15 - 25 kW.

Why less efficient ? 1. You are paying conversion costs for all the electric power, and 2. your Pulse use of engine likely occurs at RPMs that have high friction losses. 3, You are driving against higher average wind friction*

*Wind friction. I'll show an extreme speed case for ease, but the idea holds at lower P&C deltas.
Consider Case #1
x constant speed
x*x air friction

Case #2
Half the time 0.5 x speed
Half the time 2x speed

Aero friction is proportional to the square of the speed:
(0.5x*0.5 x+ 2x*2x)/2 = 4.25 * x*x / 2 = 2.12*x*x


-------------------
No ICE spin, No fuel burn: 'EV', Glide
ICE spin, No liquid fuel burn: Coast
ICE spin, fuel burn: ICE on

 

Like a lot of posts here, you are making many assumptions that are not accurate in the real world. My mileage on a recent 900+ mile trip was 58mpg. The speed limits were 65 and 70mph about half and half, and I drove a minimum of the limit. Lots of up and down and one low pass. I used pulse and coast almost all the way. I do not think you can replicate this by setting the cruise and ignoring everything else.

 

I agree; but in a similar vein, compared to the circus fat lady most people are 'thin.'

As for your 'real world', you have a one trip anecdote that for all I know was one way. Congratulations. A good place to start criticizing posts here would be the silly conclusions based on uncontrolled anecdotes with a host of unrecognized and unmeasured confounding variables.

 

If you look at the chart (too lazy to find it for everyone) that shows speed correlations, you'll see that 65 yields around 45 mpgs. This has been my experience as well over my 28,000 miles with this car.

 

If you are getting more than 70mpg then you are a hazard on the road with traffic. I respect all drivers and accelerate up to speed in a realistic time. Saying you average more then 70mpg in a priusV is a utter lie or you are driving in completely unrealistic conditions.

 

Neither. You are just ignorant. I should however point out that I was talking about driving in Albuquerque, NM in temperate weather.

 

Maybe he isn't driving in typical Alberta conditions.

Do remember that driving conditions and styles vary by region. I liked how a BC member here described I-5 between Vancouver and SoCal. Driving behavior that is typical in Washington would get you shot in California. Behavior normal in southern California would get you thrown in jail in Washington.

 

And here I thought that was what I was doing....

 

Still... 70 for a trip or two is amazing, but to actually be able to average 70 is unbelievable. Congrats on doing what nobody on Fuelly has been able to do in a V... that's with 435 cars giving input.

 

You read it on the Internet, so it must be true!