Another Battery Degradation Thread

A few things pop out at me.
At 2.2 miles - the bat temp gauges dropped to 0 degrees for a second, ( similar to but not the same as - when charging and the system shuts off for a few seconds - so the system can recalibrate the temps and SOC without the charger running - at least that is one explanation I've read explaining what the system is doing when it shuts off/ recalibrates like that during the plugin charging. )
At 7.1 miles - MPH dropped to 12 mph and at - 15.3 miles - MPH dropped to 0 mph for a second.

I've noticed strange behavior like that also with the stock gauges. One in particular is the
EV Driving Ratio - Top 20 MPGe | Page 29 | PriusChat
It adds a mile to the gas percentage as soon as the ICE is switched on and desn't seem to average that mile count.
So if in a trip the ICE is switched on for 10 seconds on 3 different occasions during the trip the gauge shows 3 miles added to the percentage, even if the ICE was only on for less than one mile.

I realize that what I've posted above may seem real nit picky but I think that knowing some of these behaviors helps me understand and use the gauges more efficiently.

I also notice it took 9 miles for the a/c to have any effect on the batt intake temp and about 13 miles before it actually started reducing the air temp at that sensor.
I'm betting the stock pack heating in the winter will show a similar but opposite scenario.
And it will be interesting to see how well the coolant heat reserve tank works too, especially over night.

 

That's the result of transmission/calculation lag. Both devices are struggling to process that data wirelessly... a lot of it, live. So, you get a 0 from time to time.

Actually, it was having an effect right away. The rate-of-increase was slowed as a result of having cooler air available. Remember, the air-intake is also affected by output from the battery itself.

And yes, it will be interesting to watch the data in the winter... from the battery, there is no coolant reserve with gen-3.

 

Do you charge at work ?

By the way, the videos are outstanding. How do you make them ?

 

I use the Torque app for data capture, then go through a series of conversions to transform the text to frames of video. It's basically just a number of saves until I get a format to match up with the scenery footage.

 

I wasn't about to let what could be the last day with a temperature 80's for a long time slip away. Here in Minnesota, Fall is about to begin. That means collecting data on how the battery is kept cool will soon end, ushering in the opportunity to observe battery warming.

I parked the Prius outside in the morning, set the timer for afternoon recharging, then walked to work. The weather was a mix of sun and overcast. That only kept the air temperature from getting really hot, but it still got nasty humid, which meant the A/C was a necessity for my own comfort. For battery-pack comfort, which is cooled passively by using cabin air, A/C would benefit it too... especially since it was already warm, almost 10°F warmer than I'd expect to see in the coming weeks.

The plan was to drive normally, not doing anything special whatsoever on the way home. I'd drive along the 45 & 50 mph roads to the highway using just electricity. Then upon entering the highway, I'd take advantage of the engine for merging and climbing out of the river valley. Then once on top on open 55 mph road, switch from that HV mode (mostly engine, with some battery) to EV mode (battery only). Upon reaching the 70 mph part of the highway, I'd switch to EV-Boost mode (mostly battery, with some engine).

Filming it would be interesting. I had my old smart-phone, which would capture driving data using a Bluetooth connection to an ODB-II reader attached to the Prius. That does a fairly decent job of collecting detail, though the processors on both ends combined with wireless transmission causes some zero-values in the data at times. The camera capturing video would be just a single GoPro on just a sticker-mount, aimed strategically to prevent over-exposure of the scenery without under-exposing the dashboard display. That works fairly well, though some software adjustments are still needed later to clean up lighting issues. It keeps the refresh flicker of the Eco-Meter to a minimum too.

The commute home itself was a nice example of what I typically experience. Traffic gets slowed up a bit by the highway entrance, on the bridge, and climbing the hill. But that's pretty much it. Fortunately, there's no efficiency penalty. That's what the plug is for. You get extra electricity for both propulsion & cooling.

Pay close attention to efficiency when traveling at the high speed. (Also, note how the speedometer on the Prius is calibrated properly and the raw data coming from the ODB-II reader is not. It's one of those annoying differences you cannot do anything about using an inexpensive phone-app to process the numbers on-the-fly.) Anywho, notice how even at 70 mph, the MPG gauge is held high. That's the result of the gas-engine RPM being extremely low due to the electric-motor providing most of the propulsion power at that speed. That electricity boost greatly reduces consumption of gas by favoring electricity instead. There's a button on the dashboard allowing you to select whether or not to utilize the battery power that way. Owners have coined that choice "EV-Boost" mode.

 

I like the new video with the visible stock gauges added. It made me wonder about starting off the trip going downhill. I noticed you got and extra tenth or two EV range on the lots exit ramp. My two 19 mile ev runs started with downhills also. But all of my trips from home start off uphill. There is definitely a lot more data in your latest video to compare.

I still need to figure out what the passkeys are for both the mini adapters, but I'm sure I'll get that in due course, as I search for the best $ deal pre hardware on a phone or tab with a decent cam.
I have 50 ev miles to go to reach 2k ev so I'll have a ev ratio pic in that thread soonish too.

I think I've found a run I can make with around 12 highway miles ev, but the first time I tried I didn't pay close enough attention and by the time I noticed my speed increase of 60 mph to 65 mph it was too late to keep the ICE off for that trip. I'll have to try again a few times in both directions to see if I can make it either way. I know some of what I'm trying to gauge is not exactly what you are looking at, but I hope when I get my equipment setup and tested, you will be able to see more of what I'm tracking then by me just trying to describe it in words.

 

The temperature here has plummeted. It's 30°F cooler now. Conditions have switched from being comfortable with the A/C to desiring use of the heater. That certainly will change the data for me to collect.

Last night was the first taste of it. I set the timer, but forgot to actually plug in the Prius. That's what happens when you're in a rush. Anywho, the drive out from one end of the cities to the other... without any EV charge available... resulted in an average of 59 MPG. That's certainly nothing to complain about and it got me thinking about battery temperature.

On the return trip this morning, I got 59 MPG again. But this time, I started with both an engine & battery that didn't have any hint of warmth. In fact, I had to fire up the heater. It was just 52°F outside and I was still dressed for Summer. The Fall conditions immediately revealed interesting data. The battery banks reached highs of only 79.12°F, 80.26°F, and 78.92°F. That's well below even the starting temps I had seen just last week with when pushing EV with it hot outside and no A/C cooling. HV driving clearly isn't anything to ever be concerned about.

I'm looking forward to observations with plug-supplied electricity now that the warm season is just a memory. Winter will make things especially interesting. I sure am glad for having figured out how to share all that heat data before the cool arrived. It should be quite a contrast when you're required to wear a jacket & gloves.

 

no changes here, after a few hot days last week, it's back to the low 70's, no complaints!

 

The new video is quite thought-provoking... I started in much cooler conditions with the battery-pack depleted. Notice the lower temperatures, as well as the impressive MPG despite no plug-supplied electricity:

Not plugging in doesn't mean sacrificing efficiency. Prius PHV thrives even while just operating as a hybrid, known as "HV" mode. Without plug-supplied electricity, you still get the benefit of the engine running at optimal efficiency. The electric-motor handles a bulk of the burden, frequently serving as the only propulsion source at times.

In this particular video, I left the Prius parked outside all day while I was at work. It was a beautiful Fall-like day. The high temperature was just 1 degree above the 56°F when I began the drive home. Between the cooler air and not having plugged in to recharge, the battery-pack was quite cool.

Around 100°F was the pattern for a normal high operating-temperature I observed during the Summer. So, barely seeing 74°F on this particular drive was quite intriguing. That was well below the starting-temperature I had witnessed just the week before when it was in the low 80's outside. I suspect Fall will be quite comfortable for the battery-pack. Winter observations later should be especially thought provoking, when heat is beneficial rather than something to avoid.

The start of this commute home was with me stopped at the top of the ramp confirming both video cameras, the ODB-II adaptor, and the phone-app collecting that data via Bluetooth were all working. That delay with the engine running was just enough time to for the emission-system to complete, allowing the drive down the ramp to be in EV (the engine stopped). Leaving town involved a climb out of the river-valley, so MPG wasn't anything special. But since that involved a decent afterward, the average would easily level off.

I like that scenic route. It's quite relaxing and low of traffic. The slower pace for the majority of the way is nice too. MPG hit the mid-50's well before hitting the country highway. So, it never dropped from that point on. In fact, it rose a little. In the end, results from the 17.4-mile journey without any plug-supplied electricity came to 59 MPG. It's that outstanding hybrid efficiency (travel after battery-pack depletion) which sets Prius PHV apart from the other plug-in hybrids.

 

even with the extra weight, i'm miles ahead of my '08!

 

Cold temperatures have arrived... and wow, that certainly has presented interesting new data to collect & share. We're just above the freezing mark, currently. I can't wait to see what happens when outside conditions take a drop quite a bit further.

Having the recharge end shortly before you drive most definitely influences the battery-pack. We know that electrical resistance increases considerably when dealing with frozen roads. So for those of you who get real winters, keep an eye on this thread over the next few months.

Degradation from heat clearly isn't an issue in any respect. Yesterday's drive from work to my fiancée's home certainly confirmed that. The outside temperature was 37°F. The battery started at 46°F. I was determined to push the battery. The 10-mile drive started with a stretch at 50 mph, then increased to 60 mph. That flat highway then turned into a very, very long (about 3 miles) steep climb up at 45 mph. I arrived at the top with just 0.5 EV left. The battery had warmed to 72°F. Starting the engine at that point pushed the EV to 1.0 mile estimate. I got to her house just as the EV ran out and it switched to stealth mode. The battery reached its maximum of just 79°F. That's lower than starting temperatures in the summer, and I was really pushing it.

That was quite an experience to witness. It's intriguing to observe rare data like that first hand, especially when the resulting efficiency was 225 MPG.

Stay tuned for updates and eventually some cold-weather videos with temperature data.

 

43 here today. i managed 15.1 miles on a 13.2 estimate at 22mph average.

 

Stay tuned for updates and eventually some cold-weather videos with temperature data.[/QUOTE]

You'll be happy to know in a week or so the cold temps you desire will be knocking.

 

not.

 

neither

 

Holy! Ice Road Prius Drivers?

 

Just for comparison, I went from 4.2 to 4.7 miles per KW in the Leaf to 2.1 to 2.3 miles per KW when the temps here dipped to -25, yeah negative 25.

 

Ouch !!!!

 

i start thinking florida when it drops below 50.