Where do we expect gas prices to be later this month, now that election is over?

[brycejones]

I haven't visited this forum in quite a while, but I clicked on the "Your content" link and was brought back to this [incredibly varied] thread. As ever, it's hard to believe that there are people on a tech forum who will take a slam on our pathetic two-party system so personally. I mean, seriously, do some of you folks actually know Joe Biden or The Donald? But I digress...sometimes you just have laugh...so back to tech.

My thoughts on the physical size -- and varied climates -- of the US are based on my years in uniform and all the different areas I either lived in or was TDY in. I also spent a career, both in and out of uniform, in the electrical field, so the fact that electrical storage devices lose stability in extreme climates comes for actual experience as well.

I'm sure that a few of our so-called "progressive" keyboard warriors will lose their minds after reading this, but a good old well-maintained diesel-powered engine will deliver a stable amount of mechanical power, as long as the fuel holds out, in just about any climate. A storage battery, on the other hand, rapidly loses stability in temperature extremes. If you're fortunate enough to live in an area where you don't experience triple-digits and/or sub-zero temperatures, by all means, make Elon Musk even wealthier than he already is, but, if you have to make a living in an area that experiences extended periods of temperature extremes, do yourself a big favor and read up on energy storage tech before funding Mr. SpaceX's return to his home planet.

That’s a really long post to say you don’t know shit.

 

[NWRMidnight]

I haven't visited this forum in quite a while, but I clicked on the "Your content" link and was brought back to this [incredibly varied] thread. As ever, it's hard to believe that there are people on a tech forum who will take a slam on our pathetic two-party system so personally. I mean, seriously, do some of you folks actually know Joe Biden or The Donald? But I digress...sometimes you just have laugh...so back to tech.

My thoughts on the physical size -- and varied climates -- of the US are based on my years in uniform and all the different areas I either lived in or was TDY in. I also spent a career, both in and out of uniform, in the electrical field, so the fact that electrical storage devices lose stability in extreme climates comes for actual experience as well.

I'm sure that a few of our so-called "progressive" keyboard warriors will lose their minds after reading this, but a good old well-maintained diesel-powered engine will deliver a stable amount of mechanical power, as long as the fuel holds out, in just about any climate. A storage battery, on the other hand, rapidly loses stability in temperature extremes. If you're fortunate enough to live in an area where you don't experience triple-digits and/or sub-zero temperatures, by all means, make Elon Musk even wealthier than he already is, but, if you have to make a living in an area that experiences extended periods of temperature extremes, do yourself a big favor and read up on energy storage tech before funding Mr. SpaceX's return to his home planet.

I admit, I haven't paid much attention to technology advancements of Diesel engines, but have they been able to develop technology in diesels that doesn't require truckers to keep them running, and/or plugged into circulation pumps that keeps the engine warm during cold weather so they will be able to start because diesels "use to" have issues in that area?

What is stopping electric vehicles technology advancements that developing similar options to keep the batteries warm?

 

[Paratus]

I admit, I haven't paid much attention to technology advancements of Diesel engines, but have they been able to develop technology in diesels that doesn't require truckers to keep them running, and/or plugged into circulation pumps that keeps the engine warm during cold weather so they will be able to start because diesels "use to" have issues in that area?

What is stopping electric vehicles technology advancements that developing similar options to keep the batteries warm?

EVs already have battery thermal management systems to keep them operating between the right temperatures. That system can keep you from accelerating as fast, regenerative breaking as much or fast charging as quickly if the temperatures are extremely high or low.

I saw a YT video where they left a mostly discharged EV sit out for two days in -20F temperatures. It took about an hour before the car was able to charge backup to 80%.

That might sound awful but I’ll point out that ICE cars that routinely see those temperatures in northern states have engine block heaters so they can be plugged in and kept warm. I haven’t been too impacted by it while driving in 20F-110F temperatures other than some reduced regenerative breaking until the car warmed up or some slower fast charging when it was 110F.

 

[NWRMidnight]

EVs already have battery thermal management systems to keep them operating between the right temperatures. That system can keep you from accelerating as fast, regenerative breaking as much or fast charging as quickly if the temperatures are extremely high or low.

I saw a YT video where they left a mostly discharged EV sit out for two days in -20F temperatures. It took about an hour before the car was able to charge backup to 80%.

That might sound awful but I’ll point out that ICE cars that routinely see those temperatures in northern states have engine block heaters so they can be plugged in and kept warm. I haven’t been too impacted by it while driving in 20F-110F temperatures other than some reduced regenerative breaking until the car warmed up or some slower fast charging when it was 110F.

I didn't know that about EVs, thanks!

So with that information, it's safe to say that his post was pretty much bullshit, right?

 

[brycejones]

I didn't know that about EVs, thanks!

So with that information, it's safe to say that his post was pretty much bullshit, right?

Yes it was.

 

[Meghan54]

I thought his choice of words…stability…was odd. I’m no electrical expert or anything like that, but I thought the problem was the cold slowed the transfer of ions/electrons/whatever, sometimes completely halting the transfer in li-on batts with cold enuf temps. Didn’t know that made a battery unstable.

 

[Paratus]

I didn't know that about EVs, thanks!

So with that information, it's safe to say that his post was pretty much bullshit, right?

Well I will point out that it does take power to regulate the temperature of a battery. So it does contribute to self discharge. Which results in reduced range in an EV. It’s really only an issue if you have to leave the car unplugged and outside for several days. Since I charge at home I’ll plug the car in if it’s going to be freezing and I have to leave it on the driveway because I’ve got a woodworking project going on in the garage.

For grid storage it shouldn’t be an issue as they can pull power to run their thermal systems until they are needed.

Thermal plants (fossil fuels, nuclear) have similar issues. You have to insulate and provide heaters for the cooling loops in freezing temperatures or you lose cooling and have to shut down the power plant.

 

[hal2kilo]

Well I will point out that it does take power to regulate the temperature of a battery. So it does contribute to self discharge. Which results in reduced range in an EV. It’s really only an issue if you have to leave the car unplugged and outside for several days. Since I charge at home I’ll plug the car in if it’s going to be freezing and I have to leave it on the driveway because I’ve got a woodworking project going on in the garage.

For grid storage it shouldn’t be an issue as they can pull power to run their thermal systems until they are needed.

Thermal plants (fossil fuels, nuclear) have similar issues. You have to insulate and provide heaters for the cooling loops in freezing temperatures or you lose cooling and have to shut down the power plant.

Is there a separate "hotel" battery. i.e. as small 12V standby battery in your EV or EV's in general?

 

[Brovane]

Is there a separate "hotel" battery. i.e. as small 12V standby battery in your EV or EV's in general?

Yes, because EV's still have 12V systems in the car. If that 12V battery dies, your car will not turn on. Which is kind of frustrating when you have a huge battery under your car but nothing will work because the tiny 12V battery is not working. My Nissan leaf uses a standard 12V Lead-Acid battery that has to be replaced every 4 years or so. Tesla has recently moved to 12V Lithium Ion batteries in their cars will are supposed to last the lifetime of the car.

 

[fskimospy]

Yes, because EV's still have 12V systems in the car. If that 12V battery dies, your car will not turn on. Which is kind of frustrating when you have a huge battery under your car but nothing will work because the tiny 12V battery is not working. My Nissan leaf uses a standard 12V Lead-Acid battery that has to be replaced every 4 years or so. Tesla has recently moved to 12V Lithium Ion batteries in their cars will are supposed to last the lifetime of the car.

I’m sure there’s a good reason for it but I wonder why they bother with a separate battery when you could just drop the voltage from the main battery down to 12. Maybe that’s not efficient?

 

[Brainonska511]

I’m sure there’s a good reason for it but I wonder why they bother with a separate battery when you could just drop the voltage from the main battery down to 12. Maybe that’s not efficient?

My hybrid vehicle has a button that will allow for a self jump from the high voltage battery in the event that the 12V battery dies. So these bypass system do exist.

 

[Moonbeam]

I’m sure there’s a good reason for it but I wonder why they bother with a separate battery when you could just drop the voltage from the main battery down to 12. Maybe that’s not efficient?

I have no idea but I would bet cost is the deciding factor.

 

[fskimospy]

I have no idea but I would bet cost is the deciding factor.

That’s actually my question, I would think it would be much cheaper to make a 12 volt drop than to make an entirely separate battery system.

 

[Moonbeam]

That’s actually my question, I would think it would be much cheaper to make a 12 volt drop than to make an entirely separate battery system.

Here is some info on it:

Why Do Fully Electric Vehicles Still Have a 12V Battery in Them?

It’s not very common to hear about a 12-volt battery and electric car. Most have one, but it begs the question: why?

www.midtronics.com

 

[fskimospy]

Here is some info on it:

Why Do Fully Electric Vehicles Still Have a 12V Battery in Them?

It’s not very common to hear about a 12-volt battery and electric car. Most have one, but it begs the question: why?

www.midtronics.com

Ha, guess I could have googled that.

 

[fskimospy]

That being said actually that article doesn’t explain why you couldn’t do a 12 volt drop.

 

[nakedfrog]

I’m sure there’s a good reason for it but I wonder why they bother with a separate battery when you could just drop the voltage from the main battery down to 12. Maybe that’s not efficient?

There are losses involved with transformers, yes. Going from 400-800V down to 12V is quite a jump. I doubt there's anything that would be more efficient than simply having a 12V battery on board in addition to the main battery pack.

 

[Brovane]

I’m sure there’s a good reason for it but I wonder why they bother with a separate battery when you could just drop the voltage from the main battery down to 12. Maybe that’s not efficient?

Could be a redundancy thing. With a separate 12V battery, if the main pack goes offline you have some minimal gauges and you can place the car into tow mode. With no 12V battery and just a main pack, if you lose the main pack everything goes away. I know in Tesla investors day presentation they mentioned moving to 48V for the internal car stuff.

 

[fskimospy]

There are losses involved with transformers, yes. Going from 400-800V down to 12V is quite a jump. I doubt there's anything that would be more efficient than simply having a 12V battery on board in addition to the main battery pack.

Electronics nerd alert - the battery is DC so no transformer is involved. It would be putting a resistance somewhere to drop it to 12.

Again, I’m confident there is a very good reason for this although I did just google it and didn’t find it immediately. Really I’m just curious.

 

[Moonbeam]

That being said actually that article doesn’t explain why you couldn’t do a 12 volt drop.

I decided to look for an explanation after I said I had to guess. Anyway, the takeaway for me was the use of the 12v battery to disengage the high voltage system in case of a collision and also there isn't a pressing need for change. Perhaps some manufactures do have some way to use the lithium as a backup if the 12 volt battery fails but I suspect that don't want to eliminate it for the above reasons. Just a guess I guess.

 

[Paratus]

Is there a separate "hotel" battery. i.e. as small 12V standby battery in your EV or EV's in general?

Sadly yes. To much of the auto industry electronics are based on 12V architecture so it’s just cheaper to add a 12V battery (lead acid or some are now Lion) that gets recharged from the main traction battery.

So if your 12V battery fails in a Tesla. You may have to pop the cover over the tow hook. Hit a release inside it for the hood/frunk and then jump the 12V battery to get the computer to boot so you can get into the car.

Edit guess this was already answered.

 

[Moonbeam]

Electronics nerd alert - the battery is DC so no transformer is involved. It would be putting a resistance somewhere to drop it to 12.

Again, I’m confident there is a very good reason for this although I did just google it and didn’t find it immediately. Really I’m just curious.

Now I understand what was going on when I replaced the doohickey in my F-150 that controls the heater AC fan speed. It would only blow at the maximum rate. The resistors were rotted with rust from getting hot. Didn't occur to me to understand the principle at the time regarding the fact it was a DC voltage application. Curiosity led me here:

DC/DC Converters: Devices for Converting to a Lower Voltage - Technical Articles

DC/DC converters are used in a wide array of systems in our day to day lives. The main goal of these converters is to step up or step down the DC voltage based on the application at hand while providing voltage regulation.

eepower.com

 

[Paratus]

Electronics nerd alert - the battery is DC so no transformer is involved. It would be putting a resistance somewhere to drop it to 12.

Again, I’m confident there is a very good reason for this although I did just google it and didn’t find it immediately. Really I’m just curious.

Former Space electrical power need alert. DC-DC converters exist change voltages without all the heat resistors entail.

They convert DC to AC and back again to change the voltage.

 

[dawp]

There are losses involved with transformers, yes. Going from 400-800V down to 12V is quite a jump. I doubt there's anything that would be more efficient than simply having a 12V battery on board in addition to the main battery pack.

I'd imagine there is a heat issue that would have to be dealt with dropping it that much also.

 

[fskimospy]

Former Space electrical power need alert. DC-DC converters exist change voltages without all the heat resistors entail.

They convert DC to AC and back again to change the voltage.

Ha, good to know! I was hoping you would chime in.

My expertise in this area is modest at best.