Thanks for the considered response.
On Jun 8, 2017, at 4:54 AM, Hannu Venermo gcode.fi@gmail.com [electricboats] <electricboats@yahoogroups.com> wrote:Disagree, but politely.
All the fastest RC cars are electric.
A tesla car == a diesel/gas car, in range, with much more short-term acceleration.
Diesel fuel == 13 kWh/kg energy by mass, in theory/physics.
Best tsla lion cells now, 380Wh/kg.
About 30 times less.
But only == 100W/km is actually used, in cars.
Depends a bit on what/how you measure.
65 l diesel x 13 kWh = 845 kWh. 600 km / 65 l == 50 kg, 12 km / kg.
845 / 600 km = 1.4 kW / km.
A tsla 100 kWh, at 200(-260) W/km, 536 km range, delivers == 536 km / 100 kWh.
100 kWh / 536 = 0.186 kW/km.
The tesla BEV car is approx 7.5 times more energy efficient, costs about the same to manufacture.
A 65 l diesel tank delivers about 600 km range.
A 100 kWh tsla delivers about 536 km range.
(with the older 265 Wh/kg battery of 18650-C cells).
The best (new) tsla batteries reportedly at 385 Wh/kg.
This makes battery powered long-range cruising boats possible, and shorter-range cigarette type boats possible.
A 500 hp+ engine, transmission, intercooler, etc. == 1000 kg in boats/trucks (upto 2000 kg in trucks and commercial boats/ships).
A 100 kWh older tsla-type battery == 530 kg.
With the newer, 45% more efficient 2170 cells => 300 kWh/1000 kg.
The battery would likely cost == 150$/Wh retail (112$ marginal production cost, tsla), = 45.000 $.
A cigarette boats 500+ hp engine, transmission, ancillaries retail cost == 45.000 $ (or more).
A tsla-type high-efficiency 3-phase synchronous motor is == 28 kg in mass, costs == 300$ to make, at 700 hp peak (only peak, 70 kW continuous).
A continuous-duty 300 kW/500 hp motor, not available now at mass scale afaik, approx 600-900$ marginal cost at 60-90 kg mass.
Of note;
A std Nissan-type sedan engine (130hp, +/-) costs about 3000€, the transmission about 3000€, qty 200k / year.
I used to sell CNC equipment to the manufacturers of engines/transmissions, so my numbers are real from the manufacturers.
I don´t have real data, but the marine engine and tranmission at 45.000$ retail, are about 8000 -10.000 $ each to make.
== 16.000$ total.
Because very few are made, thousands vs 200k/year, the prices/kg are 2-5x more than auto stuff.
Support and lifetime issues account for maybe 40% of retail prices.
All marine engines fail eventually, and == 99% of them on leisure boats from rusting inside, and lack of use.We are nowhere near "there".
Electric range is nowhere near the range of liquid fuels, assuming $$ is considered even in passing. Only 10 gallons of diesel in a 40' catamaran will take you nearly 100 miles…Energy density for batteries is still *way* below that of liquid fuels. energy density is directly related to how far you can go on what you can carry.One the plus side, however, if you run out of diesel in the middle of nowhere, you are pretty well hosed. But if your batteries go flat, and you have solar or wind, you can refill yourself.-RobOn Jun 7, 2017, at 7:48 AM, oak oak_box@yahoo.com [electricboats] <electricboats@yahoogroups.com> wrote:Can you imagine a cigarette boat going electric?It would need a ton of batteries to drive the motor, and then a SECOND ton of batteries for the sound system to provide the artificial NOISE factor!!! :)As for wake boats - I guess it would be politically incorrect and dangerous to suggest that boats designed with the express INTENT of making the biggest possible wake should be sunk with extreme prejudice. However...Just sayin...-- -hanermo (cnc designs)
Posted by: Rob <rob@sail4life.net>
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