An electric bus that drove 1,100 miles between charges...

[Jim]

Wow. Can't wait to see the first battery powered RV. Range of 500 miles would be fine. And a fast charging system wouldn't be of concern to many that full time. We usually drive somewhere and hold up for days, than continue on. With 50 amp available, an overnight charge would likely work for the next days travel and the cost would be fairly low (even if it's metered).

Electric Bus with 1,100 mile range on a single charge...

[pianotuna]

Hi,

Max continuous on 30 amp is 24 amps or 2880 watts. I use the Magnum hybrid inverter remote to limit my connection to 24 amps.

I'm currently at a campground which has old and weak 30 amp. I'm having to use my sola basic autoformer to boost voltage. No load voltage is 113. Putting on the fridge 325 watts, two oil filled heaters 900 watts and water heater 1200 watts drops the voltage to 100. Using the autoformer boosts that to 117 when all the items are drawing power. While cooking breakfast (electrically) today the load support cut in, meaning I was drawing more than the 24 amp limit. I suspect that means that on the shore side of the autoformer that I was drawing 30 amps.

The connection "order" is shore power to autoformer to Magnum to RV.

Of course, lower voltage on resistance type heaters means less output.

30 amps x 100 volts = 3000 watts

I suppose if I do not wish to tax the shore power connection I should set the limit to 80% of 3000 or 2400 watts.

2400 / 117 = 20.5 amps less 5% for overhead from the sola basic or about 19.5 amps.

However, there is no "heating" happening at the shore power plug in, and no tripping of the shore power breaker, so I'll probably leave it at 24 amps.

I did have a reservation for a 50 amp site--but they gave it away to someone else. I'm not too happy with them for doing so.

Thank goodness I have the equipment to deal with lousy shore power!

valhalla360 wrote:
If you only have 30amp, it might be a couple weeks to charge or longer as the house loads will eat up a greater percentage of a 30amp supply (which is more like 25amp for continuous).

[harmanrk]

rjxj wrote:
"The interesting thing is these diesel buses have such massive fuel tanks—given how inefficient they are—that it takes longer to completely refill an 80- or 120-gallon diesel bus system than it does to recharge our electric vehicles," explains Proterra CEO Ryan Popple. "So we're actually getting to the point where the vehicles that are configured for fast charge can be replenished faster than you can stick a hose in the side of a diesel bus and fill it with fuel."

According to Popple, Proterra's fast-charger can recharge a 100kWh electric bus in just ten minutes, sufficient for a circulator bus route of 30 (48km) miles or less. That's better than diesel or even natural gas, he told us: "We've gone from something that would have been considered a negative for EVs—slow overnight charging—and now we've gone to the point where EVs are advantaged relative to combustion in terms of speed and ease of refueling." (Recharging the 400kWh batteries of a longer-range electric bus would obviously take longer.)

So his system takes 10 minutes to recharge the battery for a 30 mile route. but he is claiming that is faster than the time needed to fill the tank on a diesel bus? 80 gallons of diesel, may take longer than 10 minutes to pump, but even at a low 4MPG, that is 320 miles, or running that 30 mile loop all day. Yes, each time you have to refuel you are faster, but you have to refuel 10 times more often by his numbers.

[valhalla360]

pianotuna wrote:
Hi,

9.6 per leg?

time2roll wrote:
50 amp connector for continuous duty is limited to 9.6 kW by NEC

Theoretically, if you can max out both legs, you've got 12kw. But reality is you can't continuously draw 50amps on both legs and the specs don't allow for it.

Even the 9.6kw, if pretty optimistic. If it's hot out and both air/con units are running along with other stuff, you can easily lose 1/3-1/2 of that to house loads. Then the charging is not 100% efficient so the amount that winds up in the batteries is even less.

Realistically, figure maybe 4kwh/h going into the batteries or approx 100kwh per day. Someone suggested it was a 660kwh battery bank, so figure almost a week to charge on 50amp. If you only have 30amp, it might be a couple weeks to charge or longer as the house loads will eat up a greater percentage of a 30amp supply (which is more like 25amp for continuous).

[pianotuna]

Hi Time2Roll,

So per leg 6000 X 80% = 4800 watts.

[Goldencrazy]

Solar will be the future. Clean, available and in vehicles quiet. If you dream of efficient motorhomes solar powered electric is the answer. We have the roof space.

[time2roll]

pianotuna wrote:
Hi,

9.6 per leg?

time2roll wrote:
50 amp connector for continuous duty is limited to 9.6 kW by NEC

Limited to 40 amps for continuous load.
40 x 240 = 9600 or 9.6kW
DC into the battery will be a little less due to conversion losses.

[pianotuna]

Your source is ancient history from 2013. I've seen retail prices for panels as low as 24 cents per watt.

RCMAN46 wrote:
Solar is not there yet.

If we remove all of the subsidies Solar still costs more to make the panels than they can produce.

This article

Solar panels

claims this will turn around by 2020. But I suspect they assume electric rates will not change by 2020.

Not likely as my Arizona rates just recently increased.

[pianotuna]

Hi,

9.6 per leg?

time2roll wrote:
50 amp connector for continuous duty is limited to 9.6 kW by NEC

[johnwalkerpa1]

RCMAN46 wrote:
Solar is not there yet.

If we remove all of the subsidies Solar still costs more to make the panels than they can produce.

This article

Solar panels

claims this will turn around by 2020. But I suspect they assume electric rates will not change by 2020.

Not likely as my Arizona rates just recently increased.

Agreed...and you need ideal conditions to get the maximum benefit..which rules out northern winters!

I do use solar at an off grid hunting cabin I have...but it is just to charge a couple of batteries to power a few LED lights and a water pump. Works great for limited use and low power needs but for larger needs, just not practical yet....unless you have an unlimited budget....

[2oldman]

Mr.Mark wrote:
We have Lithium Ion battery technology in our coach for our house batteries. Three batteries power the house vs. maybe 10-12 AGM batteries. We are saving a huge amount of weight and our batteries can be drawn down to 30% before the generator will come on to recharge.

They are amazing. Just drew mine down to 10% soc without damage.

[RCMAN46]

Solar is not there yet.

If we remove all of the subsidies Solar still costs more to make the panels than they can produce.

This article

Solar panels

claims this will turn around by 2020. But I suspect they assume electric rates will not change by 2020.

Not likely as my Arizona rates just recently increased.

[valhalla360]

pianotuna wrote:
That distance record is impressive. However they drove 15 mph to do it.

Yeah, reality is a city bus runs full throttle/full brake/repeat all day long. If they get a 1/3 of the reported range in real world use I would be surprised.

Someone suggested 2000 recharge cycles is what lithium battery packs are good for (not sure I buy that but let's go with it):
- In a passenger car with 150mile range and 30 mile round trip commute, that's 27yrs of full charge cycles.
- In a city bus, they will likely be doing a full cycle daily. That's 5.5yrs before they have to buy another battery pack, so they are paying $200k extra up front and have to expect at least 1 and possibly as many as 3 battery pack purchases. Keep in mind, if they dump an old diesel bus, it has resale value if it's still running. If you dump a 15-20yr old electric bus with a dead battery pack, it's likely going to be worth the scrap metal value as $75-100k for a battery pack isn't going to cut it.

[johnwalkerpa1]

Interesting potential RV use......but only if it becomes cost effective enough to be practical for common use.

There would be a few people who would sign on simply for the perceived need to "be green" but for the masses, it has to cost less than a conventional powerplant. And this has to factor in cost of electricity and repairs, not just purchase cost.

It always seemed to me that something that would eliminate the need for a massive electrical grid is more practical for the eventual transition away from conventional fuels....fuel cells, shoebox sized, cold fusion powerplants for each home, etc. Cheap and simple solutions 🙂 Maybe someday but not in my lifetime!

But, the research is good...you have to start somewhere...

[time2roll]

50 amp connector for continuous duty is limited to 9.6 kW by NEC