Another Battery Degradation Thread

your like a puppy on a leash.

 

I live in AZ and just bought a PIP there was only one for sale in the state (new) so I went to CA.

 

Here's that second video:

 

By the same token ... shouldn't a near discharge state have the same accelerated / capacity degrading effect that constant max capacity has?
.

 

This is my commute to work yesterday, in near ideal conditions... on the warm size with light traffic:

14 miles of EV... a clear indication of no battery degradation, since it matches exactly what I observed last year.

 

interstingly (to me, anyway) i feel my battery hasn't degraded much, but my estimated range has changed completely from july 24, 2013. i was up to 16.5, and so far my high is 15.7 and currently down to 15.5, even tough my driving is almost exactly the same.

 

It was a lot warmer last year! Better EV mpg last year?
Here we had about 7-8 days of 90 degree's or better last year. This year one 90 degree day and much cooler than normal in July. Hence lower EV mpg on average, so lower EV estimated on average by a little, maybe?

 

you get more ev miles when it's 90 vs 80?

 

No! But it is better than 50's -60's.

 

I don't think it's purely temperature-dependent. This morning, I saw 80 mpg driving to work through city traffic, and the temperature was in the 60s, and this is without any EV-mode driving. There is a hill on the way to work, but I have to climb it, and my workplace is a good 200 feet higher in elevation than where I live.

I'm not sure I know the answer for why it varies so much, but it may have a lot to do with the residual charge in the hybrid battery, and the way the computer calculates fuel efficiency.

 

in my mind, i should be getting more ev miles in this nicer summer and thus, higher range estimate. but, it's not pretty in there.

 

these cars are sensitive is an understatement.
so almost exactly can make a bigger difference then any of us anticipate. I was lucky to have you and retired tutor me ( mostly you two guys / persons anyways ) in the ways of ev.
But, what mine shows is also not what I'd expected to see, "both" the good and the not so good.

 

had the same thing Bisco - Boston area vortex
was over 15.0, dropped to low 14's before I sold it but no real world droppage on my repeat driving loops

golf tourney today - 50 miles RT in the Volt with 4 to spare
all good, better than good - but yes couldn't fit the clubs in the trunk without popping a back seat down...

 

I enjoy nit-picking the mileage figures as much as anyone, but I have to say, my driving experience is a bit less stressful without looking at the mileage figures all the time.

 

50 miles of ev, pretty sweet. i'd be happy with 20, ecstatic with 30!

 

fortytwok is your avatar a car pet?

congrats on the new addition and best of luck with it. Although it sounds like you should be wishing us good luck instead

 

Thanks!
The Avatar isn't a pet, and was just sleeping no animals were harmed in the making...

and no I still need luck, I'm not blind to past GM issues although Volt do appear sound after 4 years I won't feel completely relaxed over this for a number more...

To anyone considering one (that can deal with limited cargo space) I will say its a heck of a lot less challenge.
I loved my PiP but spent a lot more time looking at the screen and making sure I'd get around gas free. The Volt doesn't even measure remaining EV miles in 1/10s !

 

Below 1 mi ev left it starts getting me serioulsy tense about whether I'm going to get to my destination
Like nasa countdown ...... 3, 2, 1 opss ICE

my imagination says I'm driving a pure EV and if I don't make it to the next - available - charger, I'm ____

this phase shall also pass, probably about the same time the new car smell disappears.

 

Oh, the smell of plastics, vinyl, synthetic fabric and lubricants would normally be considered pollutants, but since our brains have become conditioned to associating those smells with something like a nice, big present, we love those odors. Even to the point of going out and buying a bottle of "new car scent" and spraying it in the car. Personally, I'd rather smell cinnamon buns.

 

Any hotter outside, you'd just turn on the A/C to stay cool. Since the battery-pack in the car also uses the cabin air to stay cool, it benefits when you're comfortable. So, this particular drive with the windows open instead was the ideal for demonstrating effectiveness of cooling without the A/C.

To add to the observational opportunity, I started the drive with the battery-pack already warm. Recharging had just finished shortly before and the car had been sitting outside in the sun since parking that morning.

Pushing the limit, I kept the engine off, climbing out of the river valley on the highway. That meant speed of travel was a little over 55 mph with the engine not running, all the power coming from electricity supplied by the battery-pack.

All that combined equates to lots of heat being generated. The system is well thought out and tolerances should stay within the normal tolerances of lithium battery chemistry. But this was a collection of circumstances most people would normally avoid. Turning on the A/C when the temperature exceeds 80°F is an ordinary thing to do. Allowing the engine to run briefly when merging onto the highway or climbing a long, steep hill is too. None of that is a big deal, but I didn't for the sake of collecting data about what actually happens with the battery-pack than, by allowing a heat push.

The data itself was interesting. Rather than starting with the usual battery-pack temperature in the upper 80's, it was the upper 90's. Specifically, the drive began with an extra 9°F degrees to have to deal with. The 45 to 50 mph drive out of the city to the highway was uneventful. Heat only went up by 2°F degrees. It was the merge onto the 55 mph highway with an immediate climb out of the river valley which pushed the temperature into uncharted territory. I hadn't ever observed it beyond 102°F.

Driving on the flat for the next 2.5 miles using just electricity only bumped it up another degree. That was nice, especially considering the speed. Then I hit the 70 mph portion of the drive. That stretch of highway meant the engine would join in. When that happens, the battery-pack continues to be drawn from. I was curious what that would do to the temperature. Turns out, that is what pushed it to the highest I had ever seen.

Watch the engine RPM when has heated coolant (for emission cleansing) to the HV warm-up temperature of 145°F, at 9.4 miles into the trip. Though brief, you can actually see the battery-pack had already reached a peak of 105.8°F and was starting to fall, even though electricity draw was continuing (as indicated by the SOC value).

I don't ever plan on driving that particular scenario again. Taking advantage of the engine to climb out of the river valley is a better use of the available fuels. That way, more electricity would have been saved for while driving on the faster section of the highway, so the engine uses less gas then.

The point of capturing data was well served. That peak temperature was nothing to be concerned about. But even so, it's best to keep the battery-pack cool, by doing things like turning on the A/C while driving and parking in the shade. Not recharging during the afternoon when the car is already warm is an obvious thing that's easy to avoid too. That's how the battery-pack will last the entire lifetime of the vehicle.