Size and weight are things you want to keep to a minimum on a skateboard that is why welding is a better choice imo. You could get more battery in same enclosure for increased range and torque or speed when you go welded.
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Has anyone ever tried using a car battery for an esk8? Why or why wouldnât this work? Electricity is hard for me =/
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Itâs just about energy density you donât get enough Wh in the given volume and mass to be worth using modern lithium cells are better in this regard for most scenarios. A lead acid based battery can deal with high discharge for using a starter to crank a motor to life and I think handles the cold a bit better than lithium but pound for pound stores less power.
Also most car starter batteries are 12V pretty sure so would want to chain few together to get to the ârequired voltageâ for our regular gearing motors and ESCs.
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yep, too heavy. i used to use nickel metal hydride (lighter than lead acid) on a 72v electric hub motor bike but even that is a lot heavier than lithium.
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ok, so how does it all tie together? Because Li-ion are only 3.7V right, so how are they better geared for out motors and ESCs than something thatâs 12V?
Well lithium cells are relatively very small so can pack a few in series in less space to stack the voltage up, ultimately the values to look up are energy density (Wh per unit mass and per unit volume) since that is what matters for getting range and portability assuming those are the criteria.
Also different chemistry batteries have different number of max cycles and deep discharge cycles vs partial discharge, I imagine someone has tried I just donât think itâs normally a good idea.
More directly to what you asked we use 8-12 lithium cells in series that ends up roughly in the 40-50V range so would need something like 4 car batteries or motorcycle batteries to get to roughly the same voltage but I donât think youâd get the same range or Wh in the same volume or space.
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Itâs been done, and it âworksâ, in that the esk8 will move under its own power. But your average car battery weighs about 40 lbs (~18Kg), and has a capacity of 40Ah.
Sounds like a lot, right? 40Ah at 12.6v (nominal voltage for a car battery) gives 504Wh, or the rough equivalent of a 12s4p lithium battery made of 30Q cells. (518Wh)
That 12s4p pack weighs just five pounds, though, compared to the ~40 for the car battery. That means the lithium battery has eight times the energy per pound.
But it gets even worse for the car battery. Lead acid batteries designed to start cars arenât built to be drained down low and then recharged. Theyâre designed to always be full, and only ever blast out a few percent of their energy to start the engine, then immediately be recharged again. If you treat a car battery like a regular esk8 battery, it wonât last long before its capacity starts to drastically degrade. To keep the best possible life, youâd have to treat it like itâs in a car: Always fully charged, and only use maybe the top 30% of its full capacity before recharging it.
If you take all that into account, the lithium battery has more like twenty-five times the energy per pound that a car battery has.
And now you know why we use them.
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A 12v car battery is actually six individual 2v cells stacked together in series to get 12v. We do the same with our packs - The most common ones we use have between twenty and sixty individual cells inside, arranged into groups stacked together to give us the right voltage and current.
Our commonly used battery setups are usually 10 or 12 cells in series - 10x3.6=36v, 12x3.6=43.2v.
You can do the same thing with lead acid batteries, but as I mentioned before, they are just so, SO much worse than lithium batteries in terms of energy density.
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there is this guy on the other forum that made a really nice vesc enclosure.
What is th easiest way to have leds inside like his? a single battery? or can you plug it right into the vesc?
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There are several different ways, depending on exactly what kind of LEDs youâre using (bare LEDs that need a driver, or LEDs with their own current limiting such as the common LED strip), and how many LEDs you plan to use.
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The vescs have their own internal power supply to run themselves, and they can supply up to 5V, 1A for external items such as receiver, hall sensors, and, yes, LEDs. Iâd stay well under that 1A limit though, donât want to risk stressing the vescâs power supply.
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Using a dedicated switchmode regulator like Brian mentioned is a good option if youâve got 5v or 12v LED strip that requires no special current limits.
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If youâre using bare high power LEDs (like for a headlight, or similar. âhigh powerâ means more than ~0.5w per individual LED) with no internal power circuitry, you can get dedicated constant-current LED driver modules that will run from the main battery just like the above. These are what I used for my headlight and tail/brake light.
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If you donât want to screw with any of that, you can always just get a small USB power bank and some USB powered LED strip, and recharge the power bank regularly.
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link please, like @wafflejock i suck in electrical stuff so i prefer to be directed to what works and try and understand from there 
Well, that is not very redundent is it 
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https://www.digikey.com/product-detail/en/xp-power/LDU5660S500-WD/1470-2178-ND/4488557
Keep in mind, this is only for bare, high power LEDs with no current regulation of their own, like what you find in headlights, flashlights (bright ones) and similar (The headlights, flashlights and etc all have something like this in them to drive the LEDs). This will not work properly with regular 12v led strip or whatever. For that, just use the DC-DC converter Brian posted. These still need some electrical knowhow to use properly - I recommend reading and digesting the datasheet.
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From the vescs 5v 1A output you could theoretically run ~16 RGB leds at full white brightness. But if itâs a good idea is another storyâŚ
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Hi guys I have a couple of quick questions about programming my vesc.
A little back ground, I have a 12s 4p 30q battery built buy tinnesinker.
The vesc is a flipsky FSESC 4.12 50A https://flipsky.net/collections/electronic-products/products/torque-esc-vesc-ÂŽ-bldc-electronic-speed-controller
And a 3000w 150a max output 6374 200kv motor from ebay ebay.com.au/itm/352800722124?ul_noapp=true.
Am I safe to set the max amps for the motor to 150a? this seems really high.
Using the esk8 calculator it says my max amps for the battery pack should be 80a is that correct? is there any advantage to setting it lower like 75a to give the battery a little bit of a breather?
Finally the deadband is to 15%, do I need it so high or at all? what do you set it too?
Thank you all in advance I would have just bought a boosted board like everyone else if it wasnt for you guys! I love your work.
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Excellent question. This thread has heaps of great info, and heaps of missing info⌠but in a nutshell, battery amps and motor amps are not the same thing.
Basically, you can set your motor amps to whatever you like at the risk of melting your motor. Set it to 150 and see if it gets hot⌠it probably will on a single drive. But be aware that limiting your motor amps too low will drastically restrict your motor performance.
But your battery amps should definitely be set to within your batteryâs capability.
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can someone do this nice math for me 
with a 12s of 40t, will i max out the possible power of a 170kv 6374 3510W 65A max motor?
thx!
Depends how many parallels of the 40T you have, 1p youâll be only giving the motor a constant ~35a, 2p @ ~70a etc.
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It just depends on the circumstances of riding.
The motor pulls the amps. The amps donât just go to the motor because the battery is capable of outputting that much. How much you weigh/your throttle settings/how hard youâre throttling/grade of incline all go into it.
As @itsrow has said though, youâd need at least 2p groups to pull that.
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