Hey all! What a great resource and place to glean knowledge! I truly appreciate that we live in a world where we have such a wealth of empirical data available! Thanks all for the trials and tribulations that allow noobs the ability to jump in and have a more trouble-free experience. I’ve been the trial and error guy before, just not in ESk8. I’ve got a new Trampa Complete(open belt drive) and I’ll be powering it on for the first time tomorrow with the 12s8p pack that I had built. My questions are:
Should I just run the VESC with the setup that Trampa sent it with?(I’m guessing not)
What things should I change in the VESC tool to maximize my setup?
I’m guessing I need to setup the VESC for my pack and also for the regen braking.
I’ve also read some about duty cycle and this is all a little intimidating as I’ve never used the VESC tool.
Help me not kill the most amazing skateboard I’ve owned in my 33 years of kicking and pushing!
I don’t know what Trampa sets it up as. I assume they set it up so you can ride it right out of the box (once you put the batts in) @Trampa? Maybe not due to varying battery options. Good idea to look it over though!
Check the battery cutoff limits to be sure they activate at the desired voltage level for your pack. It’s mostly a personal thing but for li-ion I set the absolute bottom cutoff to 3.3 volts per cell, some will say lower is ok, others want to keep it a bit higher for the best lifespan they can get. Personal preference but not too low!
You might have to do motor detection, once again I don’t know how/if they set it up. Super simple if you need to do it, the VESC tool is very intuitive with the basic functionality like that, just use the wizards. Might need to calibrate the remote as well, this is all speculation. That’s in the wizard too.
As far as power limits go; batt max amps shouldn’t be more than the rating of your pack. Take the cell amp rating and multiply that by however many p-groups you have. Batt regen should be however much you need to have safe brakes. You can also fiddle with the motor amp limits for low speed braking/power limits. These relate to battery amps somehow, but not directly 1:1 so you can have higher limits there than you’d expect for batt limits.
Hope that helps lol. Not very helpful without knowing how it’s set up originally.
The 30q is an odd one out where the official rating (15 amps) is lower than what it has been proven safe (20 amps). Running it at 20 will likely reduce it’s overall lifespan slightly but nearly everyone here runs them at 20 because they are willing to trade that for slightly more output. With a pack as big as yours you might not need all that power and can be happy with keeping within Samsung’s spec.
15 amps x 8 groups = 120 amps capable
20 amps x 8 groups = 160 amps capable
If you’re messing about in the settings I recommend setting at Samsung’s spec and upping it a bit if you want more power after some rides.
With dual esc’s I tend to edit each individually because I’m anal about that but I believe the VESC tool has the option to forward the settings over CAN (the wires that the esc’s communicate with each other through). Should be an option in the wizard.
VESC tool can be a bit cluttered when not using the wizards but poke around in all the tabs and it’s somewhat self explanatory. we’re here if you have questions, and there’s some nice guides on youtube.
Vescs need their values edited on each vesc over can separately!
Only the wizard edits the value on each vesc, but even that lets out some info, like battery series count, wheel diameter, gear ratio, on every vesc except the master.
I recommed a bluetooth module. The android app is just as cluttered, if not worse, but not having to take things apart to adjust parameters is priceless
It has a BLE module on it from the factory I believe. Should I just use that and connect to PC the first time or should I use a cord?
I figure after I have it all set up I can just use the app going forward.
120A For the whole pack, so 60A per ESC if going with two. (70A per ESC if you’re feeling spicy )
Battery regen can be set to 8 * 3 * 1.33 =~ -32 for the whole pack, that would mean -16 per ESC but I would set it to -20 or something per ESC.
8*4000 = 32000 = 32A. Battery regen values are set with a minus in front in the vesc tool hence the -32A. This can be safely set up to -48 for the whole pack, or -24 per ESC since braking is usually short term and not long like conventional charging. Most people would rather sacrifice some cell life over personal safety.
Your safe range is 120A continuous, 160A burst. This has to be divided by the number of motor controllers ( ESC’s ) you have. The same goes for the negative values but this applies to the cell charge characteristics.
I follow you now. Also, as I understand I cannot do any braking on a fresh charge. I’m guessing I should make sure to discharge the pack some before braking? It is also possible to set up braking without the regen too, correct?
You can brake on a full charge. Safety over cell life. Just don’t go rolling down a steep long hill early in the morning straight off the charger or you will buy new batteries every 2 months, or new vescs, or both.
In short, vesc transforms that braking power into voltage a step higher than what the battery gives.
If you brake hard on an empty battery, you’ll probably see your pack spike by up to around 10v.
Now if you do that same braking on a full pack, that is 9.6v away from the voltage things start to blow up… you get the idea.
That’s before considering the damage overcharging does to batteries.