Electric school buses are coming....can RV's be far behind ?

[radar]

Originally Posted by nothermark

The concept of towing a generator used to charge the batteries of the towing vehicle is a teaching classic.

It's well understood by anyone with a good education in basic physics. The losses will be there and will be significant.

That said, if one is towing an EV as a towed for something like a DP it would be a way to make up for the lack of charging stations. If the code writers could figure out how to only charge on down hill runs and one picked the best route it would still not hit 100% efficient in the overall package due to the energy needed to get up the hill. Flat country would be a bust. Not enough braking time. The real question is whether it would be cheaper to modify the vehicle to do that or to just put in a big enough diesel generator to charge the EV overnight.

The existing crop of 10/12 K onans would be fine for charging overnight when dry camping. The 7500/8000 would work but it would be much slower because it is 120 volt only. The 12K's are 240. 32 amp 240 will charge most of the existing crop of EV's overnight without a problem. If staying in an RV park just negotiate a price with the owner for the extra power the charge process would use. It will depend on the EV of course. Some are 30 KWh some are 100 KWh and everything in between. We do this now although to date no one has asked us for more money. Our car has a smaller battery though and it usually is never under half full.

[vincee]

Hmmm, running a gas or diesel generator all night to charge an EV? Now that doesn't make sense. I get the fact that your running a small fuel engine instead of a large diesel or V10 motoring down the road, but dependence on fuel has not been eliminated.

[radar]

Originally Posted by vincee

Hmmm, running a gas or diesel generator all night to charge an EV? Now that doesn't make sense. I get the fact that your running a small fuel engine instead of a large diesel or V10 motoring down the road, but dependence on fuel has not been eliminated.

Good morning. Well, I think this approach would more be used when dry camping. In this case I don't think the goal would be to eliminate fuel use but to still be able to have an electric drive train even when dry camping in out of the way places. The vast majority of the time the RV'er would still charge at conventional fast charging facilities like CHademo, CCS or in the case of a Tesla drive train a Supercharger facility. Or charging at home on a stove plug or even in a regular campground when staying for a night or two. Having the diesel gen option would still allow for occasional off grid camping and accessing more remote areas without charging infrastructure.

[msturtz]

I think some in this thread people are missing the scale of the amount of power involved. This is simple math. My company is designing and building commercial hybrid trucks. The minimum size of the battery pack is 600 KWh for acceptable battery only range. The charge voltage is 600 VDC provided by 3 phase AC power for overnight trickle charging.

Let’s calculate the amp draw assuming 100% of a standard 50 amp 240 VAC circuit is available. Assuming a power factor of 1 50 amps * 240 vac = 12,000 Watts. 600,000 watts /12,000 Watts = 50 hours to recharge the RV motive battery.

I don’t think many RVers are going to be willing to wait 50 hours to recharge their battery bank. Keep in mind that the power is being consumed to recharge the motive battery not running the air conditioning, cooking or other household loads.

The next problem is that the electrical grid isn’t designed or constructed to allow maximum current draw on all circuits at the same time. This holds true for both houses, factories, RV parks, offices, and even the power grid itself. The reason we get away with EV charging is because most people don’t have them. Consider what would happen if every household had two drivers each with one 100 KWh EV. Both drivers arrive at home and plug in their EV at 6 pm to a 50 amp split phase 240 vac circuit. This means their home is drawing 100 amps from the grid. Note this doesn’t count the base household use from the home. Most modern homes have 200 amp panels. With normal household loads they will be drawing close to or at 200 amps. Multiply this by x number of homes for a grid not designed for that level of power draw and we have a major supply and distribution problem. Now let’s add EV trucks and RVs to the mix and our aging electrical grid will be severely stressed. Just to address the “my battery isn’t fully empty” issue. It doesn’t matter, the instantaneous current draw is the same it is just how long it is charging for. My Nissan Leaf charges at 6.6 KWh till it’s full (about 29 amps @ 240 vac).

The solution is to string more power lines and larger power plants. Solar and wind can help but will be minimal considering the scale of the problem. Solar foot note, I got quotes for a solar system for my house that would produce about 1,875 kWh per month in my latitude. The installed cost is about $110,000 including tax, permits etc. The economic lifetime of the panels is 25 years but only 10 for the inverters and controllers. Even with the tax subsidies the economics don’t work for my latitude I.e. $0.2444 per KWh before subsidies. That includes base system capital cost but not ongoing maintenance or future system replacement capital costs. It assumes a interest rate of 0% APR. Current utility power cost is about $0.12 per KWh. Home based battery banks could also help but ultimately you have to move the electrons. All batteries do is smooth out the load not reduce it. The power grid needs to be constructed for maximum peak load not to the base load for reliable utility power. If the grid is undersized then we have rolling blackouts to match the available supply to the instantaneous load.

[nothermark]

Some of us get it, some don't, hence the long discussion.

It's all moot as the bitcoin miners are going to take all the power by 2020. It's on the Internet so it must be true. ;-)

[radar]

Hmm. I don’t know. I don’t think those are realistic scenarios for electric vehicle use. I’m not sure how close we are to what a “normal household” would be and there are some that would probably drive more and some less than our daily numbers but nonetheless they are realistic...at least for our household. Here we go. Remember, I’m not an expert... but this is real world for us.

We are a two vehicle household. Both are electric only vehicles. It’s all we drive, (we’ll, other than a 40 foot diesel pusher). So typically for us, between the two of us we commute about 30 to 40 Km per day. Maybe triple that on the weekends, sometimes a little more. We typically charge our vehicles about twice a week each, and for the one that we use for our Sunday drive once more on Saturday night. (Ours are shorter range commuter vehicles and 200 Km is max range. They don’t charge all night though. Maybe a few hours as we never run them down that far. We have both a 240 volt 40 amp Station and a 120 volt 12 amp Station although we don’t use the 120 volt very often. But neither car will take more than 6.6 Kw. Most EV’s don’t. Some of the Tesla’s do but the standard charge cord that comes with a Tesla for home use is a 40 amp unit. The most our car can pull is 27 amps. But it is all selectable by the user right down to 8 amps. Although I suppose it could occur I don’t think in our household that there would ever be a case where we would ever draw more than 54 amps at 240 volts to charge both vehicles at the same time. And even that has never happened in almost three years.

When we switched to electric vehicles we went through the house and updated all light bulbs, appliances, thermostats etc for efficiency. Timers etc. We were brought up to never set the thermostat below 26 degrees in the summer. We are able to look on line and compare our house to those of other houses in our neighbourhood. For our square footage we are pretty close to normal even with two electric vehicles. Maybe 8 to 12 percent higher in some months and some months the same or lower. I think BC hydro calculated that an electric vehicle uses about as much as an electric water heater on an annual basis for average the average household.

Like I say, not an expert, but we are real world users. Just sayin.

John.

[msturtz]

Originally Posted by radar

Hmm. I don’t know. I don’t think those are realistic scenarios for electric vehicle use. I’m not sure how close we are to what a “normal household” would be and there are some that would probably drive more and some less than our daily numbers but nonetheless they are realistic...at least for our household. Here we go. Remember, I’m not an expert... but this is real world for us.

We are a two vehicle household. Both are electric only vehicles. It’s all we drive, (we’ll, other than a 40 foot diesel pusher). So typically for us, between the two of us we commute about 30 to 40 Km per day. Maybe triple that on the weekends, sometimes a little more. We typically charge our vehicles about twice a week each, and for the one that we use for our Sunday drive once more on Saturday night. (Ours are shorter range commuter vehicles and 200 Km is max range. They don’t charge all night though. Maybe a few hours as we never run them down that far. We have both a 240 volt 40 amp Station and a 120 volt 12 amp Station although we don’t use the 120 volt very often. But neither car will take more than 6.6 Kw. Most EV’s don’t. Some of the Tesla’s do but the standard charge cord that comes with a Tesla for home use is a 40 amp unit. The most our car can pull is 27 amps. But it is all selectable by the user right down to 8 amps. Although I suppose it could occur I don’t think in our household that there would ever be a case where we would ever draw more than 54 amps at 240 volts to charge both vehicles at the same time. And even that has never happened in almost three years.

When we switched to electric vehicles we went through the house and updated all light bulbs, appliances, thermostats etc for efficiency. Timers etc. We were brought up to never set the thermostat below 26 degrees in the summer. We are able to look on line and compare our house to those of other houses in our neighbourhood. For our square footage we are pretty close to normal even with two electric vehicles. Maybe 8 to 12 percent higher in some months and some months the same or lower. I think BC hydro calculated that an electric vehicle uses about as much as an electric water heater on an annual basis for average the average household.

Like I say, not an expert, but we are real world users. Just sayin.

John.

Thanks for your post John. I too have an electric car. I installed my own EVSE and yes it is "selectable" in that I can choose how much power would be requested. The problem is even with a partially discharged battery the vehicle will request the highest available recharge rate. The Nissan Leaf (which is what I have) has an onboard 6.6 KW charger but is the smallest true EV. Most other EVs have much larger chargers 7 KW on up to 24 KW. The selectable draw is set manually in firmware or via dip switches (if you know what they are). For a truly scalable solution the power company would need to be able to control the current draw directly.

[radar]

Originally Posted by msturtz

Thanks for your post John. I too have an electric car. I installed my own EVSE and yes it is "selectable" in that I can choose how much power would be requested. The problem is even with a partially discharged battery the vehicle will request the highest available recharge rate. The Nissan Leaf (which is what I have) has an onboard 6.6 KW charger but is the smallest true EV. Most other EVs have much larger chargers 7 KW on up to 24 KW. The selectable draw is set manually in firmware or via dip switches (if you know what they are). For a truly scalable solution the power company would need to be able to control the current draw directly.

Howdy Msturtz

Yah there are some more powerful chargers out there but the majority are still 7.7 KW 32 amp and below including the new model 3 Tesla. Having said that it will be orderabke with a 40 amp charger with the long range version. You can order a model S with a 72 amp 17KW charger but they are actually not that popular.

We have a Juicebox so we can just dial up or down the current with a cell phone App. Don’t laugh but we quite often dial back the current to 12 or 16 amps so it will be fully charged just before I head for work. That way it doesn’t sit at Full charge for very long.

By the way, the BMW i3 is also a 7.7 kw charger. We are a couple years away from replacing our leaf but were surprised to see the new leaf with still a 6.6 kw charger. There are rumours that the 2019 long range leaf will have a 7.7 kw charger. Not a big thing for us but I think you will see other manufacturers match the Tesla Model 3 charger. The evolution of all this is fun to watch. No idea what we will end up with but we are watching the pack. We like the model 3 but lean towards the long range leaf because of the hatchback. Time will tell.

John.

[msturtz]

Originally Posted by radar

Howdy Msturtz



Yah there are some more powerful chargers out there but the majority are still 7.7 KW 32 amp and below including the new model 3 Tesla. Having said that it will be orderabke with a 40 amp charger with the long range version. You can order a model S with a 72 amp 17KW charger but they are actually not that popular.



We have a Juicebox so we can just dial up or down the current with a cell phone App. Don’t laugh but we quite often dial back the current to 12 or 16 amps so it will be fully charged just before I head for work. That way it doesn’t sit at Full charge for very long.



By the way, the BMW i3 is also a 7.7 kw charger. We are a couple years away from replacing our leaf but were surprised to see the new leaf with still a 6.6 kw charger. There are rumours that the 2019 long range leaf will have a 7.7 kw charger. Not a big thing for us but I think you will see other manufacturers match the Tesla Model 3 charger. The evolution of all this is fun to watch. No idea what we will end up with but we are watching the pack. We like the model 3 but lean towards the long range leaf because of the hatchback. Time will tell.



John.

Thanks John
Because I’m in the automotive business I’m looking at true liquid fuel replacement. Common liquid fuel ranges is 400 - 900 miles per fill up depending on fuel economy and tank size. I can get about 700 - 900 miles range in our DP depending on if we have a toad or not. To get equivalent range for our SUVs would require a battery pack of about 300 KWh - 500 KWh since our rigs are set up for towing our cargo and boat trailers. The motorhome would likely need 900 KWh- 1200 KWh battery pack to get equivalent range to what I have now. Obviously the charging infrastructure would need to be updated to allow mass replacement of liquid fuels.

[radar]

Yah it’s definetly interesting to follow. I think I would have enjoyed a career in the field. We chose a military career and enjoyed it. Now with a second career, courses and hobbies it would be hard to go down that road now. We enjoy our EV,s though and are well suited to what they can provide for our transportation needs. We’ll need to look at something different when we retire in a few years though. . By then there will be lots of players in the EV world.

Cheers.

[Discal]

https://www.msn.com/en-us/autos/news...ing/ar-AAwHNfT

[pasdad1]

Originally Posted by Discal

https://www.msn.com/en-us/autos/news...ing/ar-AAwHNfT

https://insideevs.com/winnebago-unve...-rv-motorhome/

Other link seemed broken..... try this one

[jharrell]

Chassis: EPIC 6 Dearborn Motiv Power Systems

Doesn't use lithium, instead Sodium-Nickel, which is heavier and takes power to stay at temperature to melt the sodium, up 127kwh capacity. 240hp, 60 mph top speed, no word on payload capacity with all those batteries.

85 miles will be highway speeds, 150 would be in city low speeds, they do garbage trucks and buses already.

[nothermark]

And, as usual, their ranges are suitable for buses and garbage trucks not RV's.