It's HOT, will it harm my car?

The car should be fine.

I live near Boston. I have a scangauge to read the battery temp.

The internal temperature of the battery stays at 90 ~ F throughout the summer. When i run local it can hike up to 105~110 F. Once i drive on the highway it usually drops back to 90~95 F.

The first temperature reading in the morning after I get into the car is never lower than 80 in the summer.

 

In some occasions the battery temp will raise up to 120 F. The car will be sluggish, and engine will get louder.

Driving on the highway with AC on and fresh air mode cools down the battery quickly to 90~ F

 

There isn't too much we can do about the surrounding weather conditions in which we operate our vehicles.
One thing I credit and applaud the auto industry for doing is being keenly aware that they sell their products in environments as diverse as Arizona Desert and Alaska Snows.
I think in most design, a lot of thought goes into realizing these cars must be asked to operate and survive in this wide range of possible environment.

The Prius as a Hybrid with a battery may have a level of additional attentiveness. The advice already given about making sure your battery vent is clear, and the fan operating efficiently is good. Also, yes I think cooling the surrounding cabin as much as possible using the air conditioning a good idea.

It is nearly a separate debate. Well IMO it is a separate debate. But when I owned my Prius I remained primarily in "Normal" mode. IMO it gave the best compromise between ECO and POWER. Obviously the most "normal" driving feel.

I rarely used POWER unless I was merging onto a very crowded highway. Or for some reason wanted very aggressive acceleration. I don't argue with proponents of long term "Power" mode usage, as those that choose to do so, are happy doing it.
But IMO, yes it remaps the accelerator pedal to be more responsive. But also, it is basically telling your Prius, "I want more power". So you are more or less telling your HSD system, go ahead and put me in "Engine Power" as quickly as you can. This of course burns fuel. IMO kind of counter to buying or owning a Prius in the first place.

With time, I also learned that even in "Normal" mode, like with any vehicle if I pressed quicker, harder on the gas pedal, I could make The Prius react with just as much acceleration as would be possible in Power mode. So I really got so Power Mode was the mode I used the very least.

It impressed 1st time riders unfamiliar with Prius to see the button. But that really was it's greatest benefit.
As a general recommendation? Well I don't recommend long term or permanent use of Power mode.

 

My Prius is the 4th car that I've had in the desert, where it averages around 107 degrees in the 3.5 summer months (114 tomorrow, ugh). In each case, I lost some shine in my paint by not paying enough attention to the waxing. And once it's gone, it is very difficult to bring the shine back. With my Prius, I spray wax the car after every weekly wash and use Armor All type wipes on the dashboard as it takes a beating with the greenhouse windshield.

 

I have 80% tint on the windshield to protect the dash. You might want to look into that

 

And you might not too.
Highly unsafe and illegal to boot.
When you hit something at night because 80% of the available light coming through the windshield that you NEED TO SEE STUFF is blocked, you won't care too much that your dash is faded out a little.

 

Highly unsafe just isn't true. 80% is very light. It's just enough to take the strain off my eyes and it looks nice from the outside. It really doesn't affect night time visibility at all.

 

Isn't tint rated by the amount of light that it BLOCKS ??

NO, a little research shows that I had that backwards.

BUT that means that 20% of the visible light is blocked which is not good at night.....AND it is illegal most places to have ANY aftermarket tint on the main part of the windshield regardless of how dark it is.

 

Right, it's illegal. I'm not arguing that and anyone who would tint their windshield would know that. What I am saying is that 80% really doesn't impair night time driving in any noticeable way while still keeping out heat and harmful UV rays. Skin cancer runs in my family and I occasionally work in the desert where temps reach 120. To me and many others, it's worth it.

 

How dark can window tint be in California?
Darkness of tint is measured by Visible Light Transmission percentage (VLT%). In California, this percentage refers to percentage of visible light allowed in through the combination of film and the window.

Windshield | Non-reflective tint is allowed on the top 4 inches of the windshield.

Front Side Windows | Must allow more than 70% of light in.

Back Side Windows | Any darkness can be used.

Rear Window | Any darkness can be used.


My car is like driving in a coal mine at midnight! I believe my Llumar tint only allows 5% of light in? I got the darkest they had. My two front side windows are Illegal, yes. Not so great at night, and I avoid night driving if possible. But during the daytime I can still see out very well.

 

Plain glass filters out about 95% of UV without any help.
That is an invalid argument.

And......the fact that you don't "notice" an appreciable difference at night is part of the problem. Some people would probably say that they don't notice any difference with 20% tint. You are just fooling yourself.

That is why it is illegal. Owners can't be trusted to make the decision on their own.

I am not throwing personal insults at you; I am just trying to make the facts clear.

 

A quick note on chilling the battery.
If this is a concern, you could try making the temperature much colder, but putting the vents at the back and, specifically, NOT at you. That way, you ain't feel the wind chill effect from air blowing right at you,, so you can endure colder temperature, which is good for the battery.

 

I found when monitoring battery temps: even on cool evenings, driving along easy coastal highway, battery temp was around 35C. I've also seen little or no drop in battery temp, going from windows open and AC system off, to rolling up windows and cranking the AC. In short: maybe the credo that using AC, keeping the cabin aggressive cooled, is mostly speculative.