When to use low voltage - VESC Configuration

I see many people fret about using a low voltage power supply to configure their VESC. This is a good idea but it is not always necessary.

The only time I would say it is absolutely necessary is when powering up a VESC for the very first time, if you buy them from me you can count on this already being done. Sometimes a solder bridge will not be seen on the first visual inspection and you can fry a vesc if you attempt to spool up at higher voltages. Also if you are attempting to power an unusual motor that is not normally used, better to use caution and use low voltage.

Well sir.... what low voltage supply should I use?

Lab power supplies will often have trouble or induce unknown variables so I recommend a basic 12v lead acid battery. Nothing fancy, you can get one delivered for less than $10. Again, if you buy one of my VESC's this is not necessary unless you are using unorthodox motors.

I have run motor detection at 12s without issue on a 192kv motor. This brings up another point... motor KV and system voltage. Before running config divide 8600rpm by your system voltage. If the resulting number is lower than the KV of the motor you are going to use than your KV is to high and you need to get another motor or lower your voltage.

A 192kv motor is the absolute max you should use at 12s.

8600rpm/44.4v = 193.69KV

If you attempted to spool up a higher kv motor at 12s it could cause faults and return a bad detection. Same goes for lower voltages but with higher KV motors. Take 10s for instance. 8600rpm/37v = 232.43kv So we can see 230kv is the max kv we should use at 10s.

Thanks for the great info chaka! a few questions for you:

1) It seems like it would be nice to use a lab power supply to limit the current as well. From what i have read lab power supplies will do weird stuff mostly if you try to brake with the vesc. Are there other problems that the power supply can cause? Would it probably be ok if you don't brake while using a lab power supply? I am going to be soldering up a vesc so it would be nice to have the current limit when first testing it out, i might just do a 3 phase approach where I current limited it on a power supply to power up/flash firmware/do the initial setup, then move to a low volatage battery for more testing then to 12s. What current limits should be used? 200 ma for flashing firmware and 5 A for configuration?

2) If i am remembering my battery chemistry correctly, sla batteries can output about as much current as lipos, any reason we shouldn't just use a 3s lipo for testing if we have one sitting around?

Again, thanks for sharing your hard earned experience!

So far I have had two or three people kill their VESC by using a lab power supply. If you know what you are doing and you have a decent unit by all means use it. If you are new to the sport and in a rush to get going just use a low voltage battery around 12v. The main reason to use low voltage is to decrease the aggressiveness when spooling up for the first time.

I have tested hundreds of VESC's and have had 100% success by giving everything a thorough inspection with a jewelers loupe and running initial detection with 12v. Very little torque is induced at 12v when running detection, very low peak rpm. I have a lab power supply and I have never breached 5amps during detection even with a faulty VESC.

Sounds good. Thanks for the info. I will definitely be going over the board with jewelers loupe, that has saved me as well several times in the past when soldering smd boards. I will just plan on using a 3s lipo then for everything, thanks for the help!

I successfully used an 245Kv motor using 10s on an ebike with reduction gearing..
super dankness!! especially on freshly charged cells.. before I fried my VESC..
4.7HW on default BLDC settings..
Im running 18 speeds so I can easily red-line the motor .. no issues !!
I was tempted to add 1 more cell because of voltage drop-sag..