supersparky wrote: ↑Sun Feb 25, 2024 8:05 pm
Just read a bit more about that mega honker Ford Van that was doing crazy lap times around Bathurst.
How many laps do you reckon it could do before a recharge was req'd.
Something else to ponder, if you pulled the diesel out of your motorhome and stuck in a, say 200kw elec motor, and used the same battery that the Transit used, how long would it last before needing a recharge?
Next thought bubble, why don't electric cars have a purpose built solar panel shaped to the roof, so the can charge up when the sun is shining?
The last part first, there are cars already on the market with built in solar recharging capacity, but the area available is the issue. If you drove to work, parked in the sun for the day, then drove home again, you could travel for free most days and bring some home for V2L use, where you power part of the house load from the car battery.
The write off salvage MG4 I just bought to do an EV conversion for the Kombi has the V2L as standard equipment and a 64kwh battery under the floor.
Something else to ponder, if you pulled the diesel out of your motorhome and stuck in a, say 200kw elec motor, and used the same battery that the Transit used, how long would it last before needing a recharge?
A lot of factors to consider,
1) how hard are the cells working to deliver that 200kW to the motor and how long would it be required to deliver that output?
2) How many down hill runs or regenerative braking requirements will there be in the total run time?
3) Will there be any solar charging as well, over 3kW of solar will fit on the motorhome roof if I designed it to maximise the solar capacity ......
Lets say a worst case scenario, crossing the "Nullarbor" not just the plains but the part from Ceduna to Norsman, raining and a head wind, you'd be crazy to still be driving, but, the 1491kW battery I'm guessing is meant to read 1491kwh storage capacity. The 200kW electric motor would only use that output on take off and when the next gear was engaged .... just like the ICE engine, you won't drive in a gear that require the foot to the floor to maintain the required revs to be in the peak torque curve ... you would drive to the "amp meter" and find that fine balance between forward speed and minimum current draw ... so, let's say that balance is 50% of the motors capacity, 100kW, the torque is still at the max it was when the motor first spun, the rpm is irrelevant, as long as it is within the max rpm the battery voltage can spin the motor. Unlike an ICE engine, the engine rpm is not related to the energy required to spin it that fast, more the opposite really, spin it faster and the peak torque is no longer required to maintain that speed.
Back to the 100kW max power, 1491kwh / 100kW = 14.91hrs .... but I doubt anyone would maintain the power load for that long, either 100km/h limit would get you, or the sheer boredom of driving slower than that would take its toll and you'd have to pull over for a break, the 6.9ltr diesel engine in the motorhome now produces around 129kW I think and it can not maintain full throttle for long without creeping up to the 120 km/h and then the over rev limit beeper goes off if you didn't realise before then ... like it was getting more stressful to drive at that speed with the navigator/speed governor in the passenger seat giving you an earful for driving so fast ... and eventually you would see the wisdom in parking up in your home on wheels and waiting for the conditions to improve. You could make it from Ceduna to Norsman, but why would you?
The real question is, why would you install a battery with more than 400km range, you can park up and recharge to 400kwh battery in 27 days from the roof top solar (3kw x 5 peak sun hrs/day)
but more likely you would stop at an EV charging spot for how ever long it takes the charge rate you selected, (faster is more expensive) or the capacity of the charger you are using, have a rest and something to eat, you have your house with you after all, then decide if you will travel one or find somewhere to spend the night.
At a constant 100kW engine load, it would take a week for the 3kW of solar to recover the energy used in 1 hrs driving if it was against a headwind and flat going, maybe 3 hrs driving in more favourable conditions, those long low gear decent hill generate a lot of energy in a short time ....
T1 Terry