I have an odd electronics problem and with my limited knowledge no real idea about the cause.
Tow Boogie, 2x 6374, 2 complete seperate boxes with sequre 12200 and 12s2p batteries each.
No connection between the boxes, but for the data lines going to Bremote2 RX.
This used to work ok’ish, but for lots of bubbles at the prop.
Last time out, the motors were stuttering and only going to maybe 5% of RPM range.
But when steering, each motor was running perfectly as long as the other was off.
Back to land and everything was running perfectly.
But once back in the water (seawater) both motors stopped running correctly again.
Once I removed a motor wire from ESC, the other motor runs perfectly fine, even in water.
Does not matter which of the motors are disconnected, the other works.
I am completely lost about what could cause this.
There is no connection between the motors and no connection between the boxes but for the two data lines each. (RX is in a seperate box).
Also have you tried running it in freshwater? Might be some electrical trolls with seawater between the motors maybe? Since it works in the air I would try freshwater.
I do not have good access to try at a place with fresh water, but I would also assume it would work.
With some effort I could try, but I am not sure what information I would gain exactly?
If it works without problem in freshwater you can make assumptions that theres some kind of interference going on when in saltwater and narrow down what to check, solutions to try.
So each ESC is connected to GND, 5V and SIG of the Rx?
How is the 5V generated for each of the Outputs? With your own BEC? Are the BECs connected to each other?
Maybe you can draw a quick sketch of your circuit including this 3rd battery for Rx?
One 18650 at the RX.
I also tried with a stepup module to 5V, but it does not make any difference.
The complete setup used to work without electrical problems for 10+ times.
I probably damaged something somewhere, just no idea where or what to look for.
So both GND of ESC0 and 1 are connected?
Then that will be your problem!
Solve by splitting them again, in your case take a 2nd 18650 and use one cell for each ESC separately
Or just use the BREmote BEC board and connect to battery voltage of ESC0
Or use a modified BREmote BEC board to generate a 2nd independent voltage with only one 18650 cell, I can send you one if you want.
This is a quick sketch of the problem
The ESCs couple capacitively to the water through motor and wires. This current will disturb the very low voltage on the signal wire by inducing a voltage on the thin GND wires between Rx and ESCs. Thats why only one motor at a time works well.
The Rx is specifically designed to have separate GNDs because of this problem. You can imagine how the “current loop” will be broken if the two GNDs at the bottom are not connected anymore.
That is very interesting, there is no way this should work haha
The B1 also needs power and GND… Only way this could work is if it is somehow back-fed from the ESC signal wire…
Also, I would recommend the 5V boost board again (one for each ESC)
While the Rx may work OK on battery voltage, the PPM signal generated will also only be at battery voltage level, not 5V, which decreases the detection margin for the ESCs
