PFF - Pennock's Fiero Forum, PDA Edition

Electric cars and air conditioning (Page 1/2)

Cheever3000

JUL 14, 05:01 PM

I'm old enough to remember when the only batteries for flashlights and toys, etc., were Ever-Ready and Ray-O-Vac. And they SUCKED.
So I don't understand how modern electric vehicles can have any range at all when using the A/C, especially here in Florida where you need it ALWAYS.
I know nothing about EV's or even hybrids for that matter, so has battery technology really come that far, that you can go hundreds of miles between recharges, even with the A/C?
I just can't wrap my head around it. But then again, I say that a LOT these days about all kinds of things.

rinselberg

JUL 14, 05:50 PM

More powerful batteries and also, more energy efficient in-vehicle AC systems.

I can't tell you the state of play. I'm not an EV owner and haven't done any serious looking into it.

I just went to Google with "EVs" and "air conditioning" and got this:
https://www.google.ca/searc...es&as_filetype=&tbs=

[This message has been edited by rinselberg (edited 07-14-2021).]

IMSA GT

JUL 14, 08:00 PM

From one of the articles posted above:

Vehicle was a Tesla Model 3

No AC running - 234 mile range
AC running on auto - 200 mile range
AC on full with all seat warmers on - 173 mile range

theogre

JUL 14, 08:08 PM

AC Does effect Range you drive on electric vehicle.
Heat in "Winter" can effect that too.

Ignore the hype from anyone claiming no issue.
How "bad" this is depend on many things but in general terms...

While Hybrids can run on gas/diesel when battery is low/dead, amount you drive on the battery is reduce by using AC Heat or Both.
Remember Many vehicles like Fiero have AC and Heat to Defog windows etc. under some conditions. AC will reduce the humidity trying to defog.
Many others has Electric glass for this but eats power too.

Most have extra E-motor to compress AC. Some may use Peltier cooling but eats a Lot of power. (Worse, you have to dump heat for whatever to cool PLUS heat generated by the Peltier pack itself.)
Many have gloried Resistor(s) for heat.
Plus need AC/Heat blower(s) and Fan to force air thru AC Condenser.

Plus many don't know Battery "packs" need cooling or heating to keep them in range of operating temp.
This is why Many have EG Coolant same as ICE flowing thru the packs and E-motors.
Others are Air Cooled.
Range on battery take a hit when the "packs" get too hot or too cold for any reason not just whatever load on them and charging making them heat up.
Nissan Leaf had/have problems in hot areas because using "Air Cooled" battery packs.

To See Battery opt range easier example is E-tools...
Battery way too cold/hot and most good tools brands won't run a tool or even charge.
If "just" near hot/cold limit at minimum won't run long as same battery between ~ 50° to 90°F
Why you don't keep tool batteries in the car etc where they see Freezing temps or above ~ 100°F. Car Cabin can reach 150° to 200°F when parked and faster then most think and even on cool days.

------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave

Rickady88GT

JUL 14, 08:29 PM

The size of the battery system matters as well. The battery is HUGE. But compared to lead acid "old school" " golf cart" batteries, the new batteries are MUCH better, but still huge in the car.

randye

JUL 14, 10:08 PM

quote

Originally posted by IMSA GT:

From one of the articles posted above:

Vehicle was a Tesla Model 3

No AC running - 234 mile range
AC running on auto - 200 mile range
AC on full with all seat warmers on - 173 mile range

Latent heat load, Q_ {l} = 0.69 * CFM * Delta W Q is a part of the A/C problem as well as delayed heat load from lights, and other equipment.

"There is no such thing as a free lunch" especially when you have a finite "power budget".

Turn on the headlights = power draw

Turn signals = power draw

Brake lights = power draw

Back-up lights = power draw

BCM for computer control of things like anti-lock brakes, etc. = power draw

Turn on the interior lights = power draw

Exterior convenience lights = power draw

Power windows = power draw

Power door locks = power draw

Power mirrors = power draw

More people in the vehicle = increased vehicle weight = more power draw

Turn on that radio = power draw

Turn up the speed on that HVAC fan = more power draw

Charge that cell phone, laptop or tablet = power draw

Lots of things eat up that power budget.

quote

Originally posted by Rickady88GT:

The size of the battery system matters as well. The battery is HUGE. But compared to lead acid "old school" " golf cart" batteries, the new batteries are MUCH better, but still huge in the car.

Yes the newer Lithium Ion and other batteries are better in a lot of ways than old lead acid storage batteries but the ratio of battery mass to storage capacity is still a problem

AND don't forget that it also takes a lot of that aforementioned power budget just to haul around the weight of those "HUGE" batteries...

....and the mahoosive weight of your morbidly obese cousin and his equally lard-assed friend.....and their luggage.

[This message has been edited by randye (edited 07-14-2021).]

Rickady88GT

JUL 15, 12:04 AM

quote

Originally posted by randye:

Yes the newer Lithium Ion and other batteries are better in a lot of ways than old lead acid storage batteries but the ratio of battery mass to storage capacity is still a problem

AND don't forget that it also takes a lot of that aforementioned power budget just to haul around the weight of those "HUGE" batteries...

....and the mahoosive weight of your morbidly obese cousin and his equally lard-assed friend.....and their luggage.

What people do not realize is the size, completely and mass of the cooling system required for the batteries. The batteries have their very own cooling system. Cars like Tesla even run the A/C when the car is parked and turned off. The reason the air runs is to keep the sensitive electronics from overheating while the driver is away from the car. It uses A/C with or without a driver in the car. That is one reason why they want to plug in everywhere they go.

TheDigitalAlchemist

JUL 15, 10:37 AM

quote

Originally posted by Rickady88GT:

What people do not realize is the size, completely and mass of the cooling system required for the batteries. The batteries have their very own cooling system. Cars like Tesla even run the A/C when the car is parked and turned off. The reason the air runs is to keep the sensitive electronics from overheating while the driver is away from the car. It uses A/C with or without a driver in the car. That is one reason why they want to plug in everywhere they go.

Went to an event at the Tesla Museum recently and spoke with some "Tesla Car club" folks. very nice, not snooty. Wish the Teslas were half the price. 100-120K for an SUV makes my brain go "Whooof"...

Most modern cars are "hands off" when it comes to repair and routine maintenance, but wow, there's just nothing to do except for tires, brake pads, and coolant. everything is tucked away. I'm sure repairs to replace batteries, motors, and other stuff adds up, but its pretty sweet (unless you are someone who likes to working on motors, in which case, its a nightmare!

But if you have the cash, the Tesla is pretty dreamy. unless something goes wrong. But then, you just throw cash at it. Similiar to Mac stuff...

RWDPLZ

JUL 15, 11:21 AM

quote

The Model Y SUV costs half that, starts at $53k

https://www.tesla.com/modely/design#overview

Due to regenerative braking, you also replace brake components far less often, about as often as you would need to replace worn-out suspension components. The Model S, at least, does go through tires pretty quick.

The major problem with Tesla repair, is only Tesla can do it, with few exceptions like Electrified Garage, since you frequently can't buy the parts. Hopefully Right to Repair gains traction and forces Tesla to start selling parts directly. If you live in California, it isn't a big deal. If you live in a state like Michigan with a strong dealer lobby trying to stop Tesla from doing business, it becomes a major PITA.

Fats

JUL 15, 12:30 PM

quote

Originally posted by TheDigitalAlchemist:

Went to an event at the Tesla Museum recently and spoke with some "Tesla Car club" folks. very nice, not snooty. Wish the Teslas were half the price. 100-120K for an SUV makes my brain go "Whooof"...

Most modern cars are "hands off" when it comes to repair and routine maintenance, but wow, there's just nothing to do except for tires, brake pads, and coolant. everything is tucked away. I'm sure repairs to replace batteries, motors, and other stuff adds up, but its pretty sweet (unless you are someone who likes to working on motors, in which case, its a nightmare!

But if you have the cash, the Tesla is pretty dreamy. unless something goes wrong. But then, you just throw cash at it. Similar to Mac stuff...

I like my Prius, and was amazed at the amount of money it saved me on my "commute" (12 hours each way). I was seriously saving $100 on each trip.

I saved enough that when one of the cells on the battery bank went bad (because I park the car for months at a time and don't drive it.) , I didn't even blink at paying to replace the entire battery pack with a brand new one. It was a no brainer.

BUT I didn't pay used Tesla prices for the thing. I paid used Toyota prices for it.

I looked at getting a Tesla, and even with free supercharging and the free plug in at work, I wouldn't be able to recover the purchase price, ever. The Prius paid for itself in two years*. (*Compared to the Lincolns I was driving.) I couldn't find a used Tesla that would give me the same ROI, or really any ROI.

I like the Tesla, even with the poor build quality reported from many. I think most that are buying them are just getting them to virtusignal, much like the early Prius owners did. I'd hope that the prices lower on them as they get older, but the company would have to release its stranglehold on the software running them, or companies would need to hack them to keep using them. Tesla has worked to keep the prices artificially high IMO.

My AC is electric in the Prius. I can turn it on and it'll run for a long time before the engine kicks on to charge the battery up. They have it down to a pretty efficient setup, and there are coolers that run off of solar power.

The AC in the sleeper on my semi runs off of batteries. I can run for over 8 hours at my "Hanging beef in here" temperature, and it's fine. That's running off of 4 deep cycle 12V batteries. That's with my fridge, computer, and various other devices using the juice as well. Some trucks have solar panels to help boost the charge and allow the AC to run even longer.
The heater is a little less "environmentally friendly." It's diesel powered.