Ciao Fulvio ti ho scritto in privato, controlla i messaggi PM.
Ho risposto alle domande sulle curve di scarica, sulle batterie e sui circuiti separati.

Hi Fulvio I wrote you privately, check the PM messages.
I answered the questions about discharge curves, batteries and separate circuits.

BobbyN thanks for the clarifications i will check your way.

I would not connect two voltage sources (i.e.. batteries) to the same receiver. Could be hazardous to the receiver's life.

Lew
Florida, USA

Hi Fulvio

The first thing you should do is check the voltage on your battery. You said the RX voltage was coming up as low. The two likely causes for this are the battery itself is faulty or the BEC component of your speed controller is faulty. So the first check is to put a multimeter across the battery and if it reads less than 6V you need to replace the battery. If the battery is OK then unplug the lead from your speed controller and carefully check the voltage between the red and black lead this should read above 4V (niminally 5V) depending on your ESC and radio. If this reads OK then you need to look further.
Because you said sometimes you get the low voltage warning this may be just a loose connection so when the boat is running on the bench just slightly wiggle the connections to see if you get a reaction. If all else fails you could try a new receiver, in my experience this is unlikely to be the problem but I have seen it happen before.

Hope the above is of some help.

Hi Fulvio, I'm replying to your private message, but if you want I can duplicate the reply here too.
It may be of interest to others.

Good morning Fulmic,

If the 6v lead acid battery is giving a low battery signal, then the additional 6v battery is probably not going to solve the issue.

Check your receiver specifications for voltage input range!
You may need to power the receiver with a separate higher voltage battery, and wire the motor independent with the 6v lead acid.

Good luck