Hi! My first build will be experimental and almost as cheap as possible, just to get a feel for it.
I need the electrics and my absolutely maximum budget is 100 euros.
I will be using either a motorcycle(10-12ah) battery or for long distances 105Ah car starter battery, secured on top of a basic 8" deck.
Which includes N5065 400kv 1285w 12v motor and belt transmission.
I am having a hard time choosing a speed controller. Firstly i was going for a simple PWM controller but could not find 100A ones. And now i’m looking for 120A ESC’s. Since i will be using lead acid battery… i am confused if ESC can be used with lead acid?
Can you find me a somewhat trustworthy 12v speed controller and care to explain why i should use it?
Out of curiosity, what kind of rough range(km) estimate would i be looking at with 1285w motor and 105Ah car battery?
Out of skateboard context:
I am also planning on building a super simple and light 12v outboard/trolling motor for my inflatable rubberboat. And i need a proper 1-2kw motor for it which will be ran by 105Ah starter battery.
I really considered a trucks tail-lift motor which was 12v 2kw but turned it down since it’s not designed for continuous use.
Do you know where i could find a proper 1-2kw 12v dc motor for this project?
say you have a motor that puts out 1800 Watts. (roughly 2.5 hp) Since Watts = Volts * Amps, and you have 12 volts, that leaves you pumping a blistering(literally) 150 Amps into a single motor. Thats a ridiculous amount.
Edit: and also waaaaayyy above what its rated for (and those are chinese amps which are smaller than real amps)
12 volts isn’t really a feasible voltage for Eskate. try 2 batteries in series, 24v should get you a bit further.
no it isnt. check again. its brushless, you need an ESC to make the 12v dc into an AC signal to drive the motor.
OK, so my disclaimer is don’t do this, you’re very likely just going to melt something and hurt yourself.
I have been given such advice and taken it and now im alive for it so ya know, just don’t die cause then i cant tell you “I told you so”
HOWEVER, this ESC will theoretically do what you want it to do. But it will also likely melt very shortly after.
Google for energy density of Lead Acid vs Lithium-Ion/Lithium Polymer to see why pretty much no one here has used a lead acid battery. All batteries pose some risk but the size/weight of lead acid for the power they can hold isn’t worth it in this case. Lead acid car batteries are designed for very high amp draw for a short period of time to kick the starter motor over and get the engine running but don’t have the same watts per liter or watts per kg compared with lithium based batteries.
Extra mass means more inertia, slower acceleration/deceleration, more volume means you need a place to put that thing (away from your feet, typically under the board is where everyone straps the lithium cells)
Also previously mentioned but to get 1285W at 12V would be 1285/12 = 107A which is a high value for amperage, most components will be rated less than this and would fry with any extended amount of 107A current flowing through them (that said most people won’t hit peak values but still, we are typically running 40-50V and at peak will draw 15-25A when accelerating depending on rider, ride style etc., 1/4 the amps is 1/16 the heat being generated/dissipated, I^2*R, so 2A = 4R, 8A = 64R where R is a constant… for the most part)
In general to compare apples to apples you want to look at Wh of a battery to know the capacity (Ah x V) that and the discharge rate are the two most important factors (aside from physical dimensions/volume/weight) . The 10Ah motorcycle battery might be more manageable size wise but 10 x 12 = 120Wh whereas my two lipo 5S cells in series to make 10S at 5Ah a piece is 185Wh (and probably around the same size)
Bracket is not a problem for me, it can be remade. Since i have only 60mm wheels and not going for wheel drive, planning on remaking the trucks out of stainless steel with a spinning axle and pulley attached on the axle.
Anyway i have asked for cancellation on the 400kv 12v motor kit order. 24 or 36 volts seems like better option, and those can be ran with few motorcycle batteries. I just like cheap(er) and more practical things and finding multiple purposes for what i already have. Lead acid batteries are easily available and i have them anyway.
As far as batteries go. DC volts are DC volts, no matter where they come from. Any ESC made for 3 s (3 x 3.7 = 11.1v ) will run with a 12v car battery. Should it be done? I mean, besides the fact that it weighs a metric f**kton I suppose why not? In general anyway. I’m sure someone here will want to tar and feather me for saying that.
I think i heard @b264 audibly groan from thousands of miles away.
For Eskate, 12v is going to be gutless.
and you’ll need high amps (lots of amps = lots of heat = lots of $$$) .
If you’re dead set on lead acid, then get 2 or three in series, and that will be for 6s or 9s.
This also means you have to figure out your own charging method.
If you want this to work. Put a list together of what you have already, a budget with which to buy. and then we can help you build a board. Failing to plan, is planning to fail.
Definately, lead acid is my way to go! 24-36v battery bank made of 2-3 motorcycle batteries just has to be changed from series to parallel and those batteries usually have bolt terminals; can be done but might not be really practical. Or charge them seperately.
Indeed failing to plan is planning to fail but failing sets things into a clearer perspective. I tend to start from the simplest, it seems to be the only way to know what’s really needed.
I still hang onto that 100 euro budget, only with different voltage which is now 24-36.
Would that be enough for a reliable motor and esc?
I’d like to hear your opinion about a 12v outboard with 1-2kw motor. It’s just much practical to use a big car battery than 2-4 smaller ones with less capacity.