Thanks to Allannde and his knowledge regarding the traction battery I did some "sperimenting" today. Allan and others on here have warned we newbies to take care of the bat. I told Allan I was finished with charging it in the heat of the day and would use the timer. I lied. I came home from a 100 mile drive today and decided to use what Allan had shared with me...how to make my Scangauge ll show the bat temp. So I put in the code necessary to see that parameter and set to work. (And at the same time how to shut off the annoying back up noise ... this code was supplied by people on here...thank you.) In my garage the temp was 77 according to the car. Not scientific I found. I checked the bat temp before attaching the charger. It was 82 degrees F. Started the charger at 2:20 PM. Every 20 minutes I checked the bat temp. It gradually rose ... ending at 87 degrees F. The temp in the insulated garage had risen by 1.5 degrees. So my non scientific result is that the exact 2 hour charge produced an increase of 3.5 degrees in the bat. And why I found the car temp was not scientific is because it never rose, even thought taking the temp at the rooftop on my digital thermometer produced the 1.5 degree increase in the garage itself. So for some reason the car-measured temp didn't rise. I also measured both back seat bat breathers. They obviously slightly suck in since they were always ambient with the garage air...mind you there was a difference of about 2 degrees F between them, which I assume was height. I even crawled under the car wanting to find and measure the exhaust temp of the bat air. Never did find it....lol. I still don't know where the warmed exhaust air come out. Anyone know? While I was playing around I removed the traction battery cover/back storage area floor ... and saw the cooling fans working. Their placement didn't make sense since they appear to just cool the back end of the battery pack but I bow down to the Toyota engineers...they know what they're doing. And where does this leave us....no idea. Other than knowing that the lower the temp while charging is better for the Lithium -Ion battery pack. Just raising the temp of the bat pack 3.5 degrees shouldn't degrade the bats THAT much ... I tend to agree that the cooler the bats are when starting the charge, the better for longevity. I'm wondering if longevity is going to bite Toyota in the butt on warranty, expecially in CARB adopted states. Like here. 150,000 miles.
On my 05, the exhaust battery air came out somewhere inside the right and left panels exiting downward perhaps. Also if you drilled a small hole in the exhaust pipe from the fan, you should be able to plug it up again, easily. A infra red temp reader may show a good reading.
Ok.....I'll chime in here, since I started charging at my apartment (at night) also this added tidbit, temps have been in the 70's instead of the 90's my fully charged EV miles have gone from 10.4 to 11.9 miles (previously I charged at Consumers electric around 12 noon to 3pm)
From what I saw, the fans are right up against the backside of the bats ....no pipe. That's what kinda confused me ... where is the air going? I play with/work on John Deere Garden Tractors and it's important to have the side covers on certain models since they play a part on drawing air past the fins on air cooled engines....made me wonder if I missed where the air is coming from/going to in the PiP. I did put the cover/floor back on in case it matters with the cooking.
Heat generated during plug in charging should be a lot less than that created by driving. Especially when the battery is discharging. During charging, the battery chemistry is endothermic (cooling), but not enough to offest the heat generated by electrical conduction through the electrolytic and other conductive elements. During discharge, battery chemistry is exothermic (heating) , and adds to the heat generated by electrical conduction through the electrolytic and other conductive elements. And charge/discharge rates are much higher when driving.
Chris11 is being careful and as observant as possible. This is a good thing. As I understand the issue, the problems come not so much from the temperature in the garage but the temperature of the battery when you arrive in the garage from driving. That would be the case if you charge as soon as you arrive home. Waiting to charge for both the cooler night time temperatures (where it cools at night) and the cooler battery is better for the traction battery when this is feasible. My understanding, also is that the traction battery is at its best at about 70 degrees F. Higher than that is more heat than the traction battery needs and less than that can mean less than optimum performance so that becomes the "sweet spot" to hope for. Those fans are pulling air over the traction battery which exhausts from the rear of the car. There are inlets in the rear footwell of the car which can bring in cooled air from the cabin. I monitor cabin temperature so I know the temperature of entering cooling air. I also monitor traction battery temperature and find that it varies little more than ten degrees from ambient temperature which is then the major consideration. But I also notice that on a hot day, the traction battery is slow to rise to the ambient temperature from a cool garage. It was 96 degrees out today and after a ten mile trip outside, my traction battery was still at 77 degrees. Since our driving and experience varies so much, there is no "rule of thumb" which applies to us all. If you care, get a ScanGauge and monitor your own traction battery. Chris and I have discussed the frustration of wondering what we might do unwittingly to hasten the degradation of the traction battery. Unfortunately, this is not yet a science. Li Ion batteries have not lived out their lives yet so that we can not yet know what to fully expect. And, we cannot be so protective of the cars that they become less than useful, as if that would even help. So, use what seems like reasonable caution and enjoy the car. We might need to replace the traction battery before the rest of the car dies but we might get lucky and not have to. But keep in mind that the 150,000 mile warranty will not cover natural battery degradation. It will cover manufacturer defects. Those who think otherwise need to reread the warranty.
This may have been covered before, but does anyone have the estimated/expected battery life chart? Obviously there are a lot of factors involved, but something like a # of full-charge cycles expected before a certain % of battery life is lost?
This thread discusses the issue. (49) How to extend LIMITED SERVICE LIFE of Prius PHV traction battery. | PriusChat. I think I have seen tables such as you mention but the implication of what is said in the manual is that real world conditions vary so much that such tables are only very general indications of what to expect. As significant are the expectations that Toyota has given that the traction battery will last "the life of the car" in most cases. Of course that begs the question of whether you or I will qualify for "most cases".
these same questions were asked about the prius battery 10-12 years ago. turns out they last pretty long on the whole.
