Author Topic: VEC300 - Regenerative braking and have EBS enable question  (Read 2144 times)

Offline Ripvanbl

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VEC300 - Regenerative braking and have EBS enable question
« on: September 09, 2020, 11:18:07 PM »
I have wired up a GM 48v 5K BLDC motor with the VEC300 controller to (2) 50C (burstable to 100C) Lipo 22.2v 6000mAh batteries wired in series. This has worked out great, but I'd like to enable more engine braking (and possible regenerative capability).

In the VEC controller software, in the regenerative braking section, trying to figure out how to properly set the EBS settings so it doesn't try to push too much back to the batteries. The batteries have a suggested charge rate of 1C. I'm getting an "invalid value" error in the VEC software when I try to set the reverse charging voltage to something like 6 and amps to 3. Is this not going to work with my setup?

Any help is appreciated.

Offline Bikemad

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Re: VEC300 - Regenerative braking and have EBS enable question
« Reply #1 on: September 10, 2020, 11:54:13 PM »
Hi andto the forum.

I don't know what the minimum acceptable reverse charging voltage and current figures are on the VEC300 controllers, but if it's anything like the hub motor controllers, I suspect the max reverse current is unlikely to go as low as 6 Amps and the max reverse voltage may not go as low as 50V (12S x 4.2V = 50.4V) if you're using the 48V battery settings.

The regenerative braking effect is likely to be directly related to the current being produced (below the max reverse voltage setting).
Regen braking forces are often much stronger when the battery is partially discharged and its voltage is lower.

6 Amps (1C) seems very low for a battery capable of delivering 300 Amps. The Turnigy Nano-Tech Plus 6000mAh 6S 70C Lipo Packs can deliver 420 Amps during discharge and charge at 90 Amps maximum(15C).

Try and determine what the lowest values are that the controller can accept by slowly decreasing them from the default settings one at a time until the "invalid value" error is displayed, as this will allow you to decide whether your batteries could tolerate the the regen at those values.

If the reverse charging voltage or current is much higher the safe charging current/voltage for your pack, then using regen will not be an option, but if they are reasonably close, then you may be ok to use it, as the regen will not be continuous and is likely to be just short intermittent bursts which the batteries may be able to withstand.  :-\

Alan

 

Offline Ripvanbl

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Re: VEC300 - Regenerative braking and have EBS enable question
« Reply #2 on: September 11, 2020, 12:33:55 PM »
Thank you Alan for the details. I'll give that a try and see how it goes. The recommended charge rate is 1C, but to your point, that is for fully charging. I'm sure they can probably stand more for short bursts like you said. I just wasn't sure if there was a setting or configuration I might have been missing (or mis-understanding the UI/Interface).