9000mah @ 25c = 360 cc amps 360÷4= 80 per motor. 2000w per motor/25v=80a. Looks like the math is good. They are still 400w short of my race board and I have an empty axle to fill. This board they are making, oh yeah and sell Diy parts to the community, and of course to stay on the DIY subject and not stray and be within the rules and confines of the forum governing bodies with all do respect, will be a raptor schlaptor for sure.
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@MoeStooge i was calling attention to the temperature, if you got it 
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Low volts doesn’t mean much as long as you can lay down the amps…
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Errm…NO. More heat generated by components: battery, motors, esc, truck which could lead to the bushings being softened under the heat, which is bad news for anyone going fast and needs that stability. More heat=more stress-less durability especially the wheels which in case of coaster wheels isnt an issue.
Heat is the hub killer, however delivery electronics can be made to carry any amp load at any voltage safely. Mine only carry 65% capacity and never overheat. Yup I agree, without knowing what the delivery system is capable of it’s hard to say. Hub is definitely a weak link at 2000w if 60mph is their expectation. Pushing electronics to their limits is no bueno amigo.
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the raptiods sphincters are puckering!
Unfortunately resistive losses increase with the square of current, going low voltage to reach 8kw is not going to work well for the wiring and vescs lol, but maybe they mean 8kw when you put 12s or 14s in the board?
Fred I think we’re talking Apple to apples when I say a low volt high amp system will work as well as a high volt low amp system if the delivery system is sufficient and provides low resistance and the drive system is built to play the part. The downsides of both is higher the voltage the more unstable it becomes. Lower the voltage the equipment to carry the same product gets bigger. I think finding a balance between the two in delivery design is important. We mostly use off the shelf parts so most of us fall into a volt/amp category to work with. If this is a custom design piece they made, who’s to say. Guess we will find out when the details are released.
When you say the higher voltage makes it unstable do you mean parts exploding from inductive voltage spikes? I’m trying to think of downsides to high voltage, and if they can be fixed by a more HV tolerant vesc.
As voltage increases it’s inherent traits are, induced fields increase and flashover distances decrease. Spikes also become more difficult to stabilize and keep from damaging equipment. Our ecu and voltage supply are at different potentials and it’s all about potential management. Operating electronics at or near their limits is my biggest concern with supply and demand failure. This is about where my pay grade ends.
I don’t think the flashover distance is going to be a concern - that’s more in the thousands of volts such as ESD etc where that’s a concern (~1mm travel per kV)
You are right though about the fields potentially (no pun intended) causing damage. What I think is happening is every junction you have in solid-state devices (P-N or basically a diode that exists in every FET etc) has a “standoff voltage”, and the closer you get to that the more you risk breaking down.
So just by using components a bit higher rated standoffs, or by absorbing/controlling the spikes, we can mitigate that.
My opinion is that this stuff is fairly easy to protect against, but the main thing that kills these devices is HEAT. Granted as heat increases, those standoff voltages start to decrease and the PN junctions become more porous meaning yes, “voltage can kill” the device but it’s not really the independent variable, it wouldn’t have happened if the device was cool.
the problem with the VESC that i see is that it’s been optimized around form factor, with a lot of heat just soaking into the components (for example FETs back to back on top of each other?) and not enough copper to actually utilize the DRV chip’s thermal sinking capability. I think for a given number of watts, running lower volts higher amps is going to cause bigger problems from heat on this particular VESC design - I could be wrong though
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When we’re talking microcircuits. A mm is a mile. Great back an forth going on here Fred
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All good info, OK 1/10th of 1mm (for 100v let’s say) is 100um, that’s within the rules for trace/space gaps between copper anyways on a PCB.
Now add the insulator material (soldermask) and that number jumps way way up, so I think it’s not a concern. For example the pins on that DRV chip are hundreds of microns apart from each other. you’ve got a good point when you consider little solder whiskers or some contaminants on the board.
I think @chaka is conformal coating his VESC which is a nice touch that further protects against high voltage jumps.
To get back to the point of this thread! Racing, uphill, is going to be such a huge expenditure of watts, that heat is going to be the huge problem to deal with. Large thermal masses are no longer enough as they’re going to soak up to their max temps in the first few minutes. We have to attack the independent variable which is heat, generated by resistances we can optimize but can’t get around, so if current squared it causing it, gotta get the current down - only way to do that and keep the same watts is VOLTS. let’s solve the problems with volts so VESCs can run at 14S 
That will get you up a hill
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Don’t get me wrong Fred I have 4 x 7s lipo packs at home (for a 14s2p battery), so I am a believer 
but…
Isn’t this just a cyclic argument though where 16s will be cooler than 14s or 18s cooler than 16s… because of the reduced current for said watts output.
I think their is also a jump in practicality as you start to head north of moderate to high 12s capacity loads. I mean the XT90 connector on the VESC6 speaks volumes about its max/peak capacity. Even a 7mm AS150 connector is only rated to 200A peak and you need to connect your series batteries with something that can handle the load?
I guess what I’m saying is if you push too far in any direction you run in to challenges and at this point have we actually hit a physical ceiling in any direction where by we will need a new technology to advance?
So if we are in a game of incremental gains is there a way to jump straight to the end game?
Everybody is trying to get from A to C Genius is getting there without B
Conformal coating protect against humidity… not hight voltage… The French word is more representative for the Conformal coating process “Tropicalisation” which meant something Tropicalize… or ready for tropical climate…
Oui, but why do you want to protect against humidity… it’s because a damp surface is no longer an “air gap” and it’s easier to jump the gap if you have water, particulates, etc. There’s UL requirements around this stuff (called “creepage” lol) in the past I’ve even cut out holes in PCBs (for a high voltage A.C. prescalar) to meet creepage. The conformal coat nixes that
I think I agree with you, but look at everyone else doing high powered e-vehicles, ebike guys start at 16S, car and boat designers are in the hundreds of volts… esk8s are all using hobby ESCs and have painted themselves into a thermal corner with the VESC. Vedder is a great programmer but from an EE standpoint there’s a lot of things that could be optimized or tweaked just a little bit to get to 14S.
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I agree Fred
Hey I’d love a VESC6 modified design that could handle 14 or 16s and controlled ampacity. Sign me up! 
16S @4.2v looks like 67v, maybe 14S easier to work in the same drv8032 max 60v range.
@BigBoyToys 46mph daaaam, those V3s are showing . Sounds like another round of performance day is in order…
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Where is this high toot-en malarky taking place? Did I miss something?
That’s nearly 75km/h for the rest of us in the 21st century 
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