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Discussion Starter #1
HI all first post on the site so i'm just going to ask a couple of question

i have an boat engine with a dyno start which mean it starts the engine, then when it it running it becomes the charger is there any motor out there which could do the same in regards to regen breaking ????
i'm just wondering if this is possible

2nd question
whats a gd voltage and ampage to start at for a 100mile range car with a warp9 engine on a light weight sports car
 

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i have an boat engine with a dyno start which mean it starts the engine, then when it it running it becomes the charger is there any motor out there which could do the same in regards to regen breaking ????
i'm just wondering if this is possible
Hi coone,

Welcome.

All motors can generate and all generators can motor, if properly excited. Here, "excited" means the type of field winding in the dynamo (which is an electric machine (motor or generator)) and the controller between the dynamo and load and/or source. So, one dynamo can function both as a starter motor and generator for battery charging and auxiliary system power.

But :) in the real world, a starter motor needs high current for high torque to crank the engine and a generator runs at relatively low current for battery charging and headlamps and stuff. So using a single machine (dynamo) for both functions is a compromise. It can be done, obviously. But such are usually only used on smaller engines not requiring large cranking torque. And then the generator efficiency suffers. But the good news is that it cost less to attach a single dynamo to your engine than both a cranking motor and an alternator.

And yes, this "dynamo" can be made larger and designed differently so it starts the engine, can actually propel the vehicle to some degree and charge the battery, either from the engine power or from regeneration. See the Honda hybrid system for an example.


2nd question
whats a gd voltage and ampage to start at for a 100mile range car with a warp9 engine on a light weight sports car
Pick one :confused: 144V :) A lot depends on the particulars. Hang around and read a lot and then ask some reasonable questions and you can figure it out. No one answer fits all.

Regards,

major

ps...please call it a motor (or dynamo :)), not an engine.
warp9 engine
 

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If you use a warp motor, or other series wound motor, you will likely not be able to achieve regen. Sepex, AC, brushless and permanent magnet motors can easily regenerate.
 

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Hi all...I am a newbie also..and this was my first thread that I read and WoW..A Dynamo...This is going to be a fantastic learning experiance!!

I have been in the automotive parts business for forty years and have often thought of the idea of converting :D to 'lectric. Now with all this knowledge and brain power of this board, the dream should become a reality... Looks like I have a lot of reading to do.
 

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2nd question
whats a gd voltage and ampage to start at for a 100mile range car with a warp9 engine on a light weight sports car
howzit,
sorry but as a new oak on the subject of electric cars and such... i don't think that this question is a " Read more and go figure it out" type of question...
I would also really like to know the answer to that question, and this being a forum that questions may be asked, an answer would be appreciated....
No disrespect to any1 but someone must have an idea... a more or less answer...
just to give us new oaks an idea...
I for 1, don't have a clue on what voltages and amps I will be working with when (if) i start my project.....
Obviously ill also be reading on, and researching some more, but i come across this thread and thought I'd find an answer....

Thanks,
Regards,
Gareth
 

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howzit,
sorry but as a new oak on the subject of electric cars and such... i don't think that this question is a " Read more and go figure it out" type of question...
I would also really like to know the answer to that question, and this being a forum that questions may be asked, an answer would be appreciated....
Hey Gareth,

What was wrong with my answer:confused:

If the OP or you don't want to read or research any further, use 144V. But you may find a better solution for your project by doing some legwork.

We're here to help, not to design your system for you :)

major
 

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Your current and voltage values will depend on your power output requirements. Neglecting drivetrain losses and mechanical/electrical loss, power(watts) = volts x amps, and one horsepower is 746 electrical watts. As a very rough approximation that covers some of the losses, you could say 1 kilowatt gives you one horsepower. Therefore, a car that requires (let's say) 15 horsepower to maintain some given speed will require about 15 kilowatts of electrical power. At 100V system voltage, that would be 150 amps.

Another aspect that helps to determine system voltage is power loss in wiring. Power loss (watts) = Resistance (ohms) x (current (amps) squared). So, because increasing the system voltage reduces the current requirement, you will lose less power. However, higher system voltage typically means you need more batteries in series and it therefore has a higher cost to get going at first, although in the long run it will be more efficient.

Best system design matches the battery, controller, and motor so that none are substantially more capable than the other (unless you want to leave room for upgrades without replacing all three), but usually it comes down to budget.
 

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Hey Gareth,
What was wrong with my answer:confused:
major
hahaha, sorry bud, I did read your reply but it read to me like ...."144V but who knows? you go figure it out" LOL

If the OP or you don't want to read or research any further, use 144V. But you may find a better solution for your project by doing some legwork.
We're here to help, not to design your system for you :)
major
And being that I took your answer up wrong, my point was that here I am, a new guy, doing the research and have come across a question I would have asked and sorry but in interpreting the answer incorrectly... made a dumb comment... LOL


cheers...
 
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