Oh, it’s a good point you mentioned ! I also define a very low max watt for the beginner mode.
It will be adjustable via the battery max. So if you have a 10s4P and want a power output of around 250W then you have to set 250W / 36V =7A for battery max.
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I’d like that more than max watt, one less thing to worry about. When is the new version coming out?
I have tried installing this firmware on two different maytech 4.12 VESC.
When I hit the upload button it uploads the firmware, then I get “unknown error” in the bottom right of BLDC Tool and the VESC becomes unresponsive and I have to reboot it by cutting the power. After reboot, it still has the 2.18 FW.
Am I missing something here?
I disagree with getting rid of max power. 40V * 50A = 2000W 36V * 55.5A = 2000W 30V * 66.6A = 2000W
Setting a max current is not the same as a max power.
IMO. Power (Watt) control should seek a power condition and not a current condition at a specific voltage, otherwise what is the difference???
If I can set max power, and have the throttle be mapped from 0-max power then that would be ideal. The max battery current is for safety reasons. In my opinion it should be set once and never change and always override any other setting.
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Yes (10char)
There is still a difference. I make this because of different reasons. First of all i want to get rid of max watts because people mostly didn’t really understand how to use it and it makes the code much more complicated. Secondly it works great when the max power is calculated by the actual battery voltage in combination with max amps. Because if you set the max watts to the calculation 36V * 30A = 1080W for a 10S battery then you loose throttle range when the battery is below 36V at 30A. All in all i want to have make it easier.
You won’t get a precise watt output anymore but it makes it easier for me to provide the same power to the motors. And it gives me the possibility to setup different power output for the front and rear axle. So 4WD and Dual diagonal will have a big benefit from that. It’s possible for example to use 30% at the front and 70% power at the back and for the brake 70% at the front and 30% at the back. At the moment that isn’t possible via CAN because the motors get the same current signal.
But i will give it second thought.
I see the chance to keep max watts but that would involve lot’s of programming again and it give a higher chance for messing around with the setup.
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No reason to cap the ability of your app just because people don’t know how to use it! We would still be using rc ESCs if we limited ourselves to what we know how to use already…
This is not a max power setup, it’s a max current setup. If you set your max current to 30A then you get this: 40v * 30A = 1200W 36v * 30A = 1080W 30v * 30A = 900W So throughout the trip you get less and less power of you hold full throttle. That means you loat 25% power from full to empty.
Lets now assume you control power. Max power set at 1200W. 1200W / 40V = 30A 1200W / 36V = 33.3A 1200W / 30V = 40A Regardless of the voltage of your battery, you get the same power if you hold full throttle. This means that you don’t need to adjust how much throttle you use on the same incline road as the battery discharges.
Now if your battery can only do 30A max for safety reasons then you get the same response as the current control mode since the max amps overrides.
If your battery can do 60A and you’re trying to do a beginner mode, the current control will have a varying max power as the battery discharges, whereas a power control would have the same max power throughout the whole range.
The reason most rc escs use current control is because the discharge curve for LiPos is really flat 3.75v-3.65v from 10-80% used capacity with the drop being really pronounced near 90% used capacity but even then high end escs like kontronik Jives have a power control mode in which they do exactly what I described above but it comes at a really steep price.
This isn’t so great for Li-ions since the discharge curve has a constant slope from 3.9v to 3.2v from 10-85% used.
As for the 4wheel drive scenario, you would just offset your max power on the vescs. They get a throttle command from 1000pwm-2000pwm from the receiver. All you need is to pass that through the canbus.
Rear ESC power limits: max 700W, min -300W Front ESC power limits: max 300W, min 700W
10% throttle = 30W at front, 70W at rear. 50% throttle = 150W front, 350W rear. 100% throttle = 300W front, 700W rear
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Now you convinced me to add it again. 10 hours more work. Your lucky the the 96 30Q cells for my 12S8P haven’t arrived yet.
But it will work a little different and should only be used by advanced users who know what they are doing. Because you have to set it up for each motor. Also if you want to have a equal power output.
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Hehe. Sorry… (Not really, I really really want power control)
Btw, is it a PID controller? Is there a way to adjust individual gains???
@Ackmaniac: Any idea why I get “unknown error” in your version of BLDC-Tool when uploading your firmware? After upload it should reboot but it doesn’t and when I manually reboot it still has FW 2.18.
Where did you get your VESC from. Maybe the bootloader is missing. Best is you make a video it.
It’s a maytech. It currently had fw 2.18 and it’s working. It’s just updating fw that’s not working. I’ll see if I can make a video tomorrow
I think the maytech VESCs have no bootloader installed. So you need a programmer. there is more info on vedders website www.vedder.se I don’t really understand why so many buy the maytech VESCs in the last days.
I’ll get a stlink and test, thanks for the info. Market is flooded with maytech parts so they are easy to obtain
Cheapest on the market!
BTW where are you guys getting your Maytech VESCs from in the USA?
I’ve orderd mine from http://m.ebay.com/itm/302200711613?_mwBanner=1 (3) So far 1 has a problem with getting info from the receiver
Well the one @halifax21 pointed is not the cheapest in the market it has the same price than @torqueboards
@halifax21 is this VESC for your tramps build?