Recent content by fechter

Yes, be sure to also check the black wire to make sure it's really at ground. If the ground connection is broken, it could make all the sensors read high.

It seems like all the sensors are bad. That's pretty hard to do, usually they go one at a time. If the 5v supply line made contact with a phase wire, that would do it. Any recent crashes?

How thick are your brass sheets?

Those should work, but if the dc-dc is off, what are you going to drive the relay with? Those are rated for 3-32v input, so you could find 5v somewhere coming from the controller to drive it.

Are you wanting to use the relay between the battery and a dc-dc step down converter?

Glad it worked out.

Seems like running the batteries in parallel would be low risk so you could try that and see if it’s fast enough. Lead acid batteries sag a lot under load so it might be pretty close to stock.

Correct. I learned the hard way you can't just leave the wires floating. By tying it to the cell above, that channel is effectively turned off and won't trip the BMS. But there are many different BMS designs, so some may not work like that.

If two BMSs "share" a cell, something bad might happen if one of them trips. I've used several BMSs with fewer cells by having the unused tap wire at the positive end of the string and tie the unused tap wire to the positive. This might not work with the fancier Bluetooth units.

Nice! Have you driven it yet? They might make smaller throttle pot boxes. Or you could mount it more in the center and extend the shaft somehow.

With the transformer issue I was referring to before, it was the transformer itself and not really the load that was causing breaker trips. They make solid state relays that only switch during the zero crossing. If you could turn on the transformer with a zero crossing relay instead of a...

I'm not sure how long they take to cool off. It might be more than 10 seconds. If the power is cycled too quickly, the breaker might trip. When the motor starts, it's going to have a pretty big current inrush until it spins up. They make time delay circuit breakers designed to handle motor...

I've seen some equipment that just used a big NTC thermistor in series with the AC line. Without it, the breaker would trip sometimes. With it, the breaker never tripped. The trick is to choose the right size for the application...

That lightning has a way of starting fires. I'm getting smoke from the fires in Canada. Otherwise sunny and windy.

That place has some nice (and cheap) batteries.