Hi I'm pretty new to circuits and I have a question about charging a battery for a project.

How do I keep the port from being an open circuit when it is not plugged and being charged?

Will a relay work to engage the port when charging and disengage the port when no charging is applied?

Thanks you for the help.

 

Have you got a circuit in mind that your using?

 

I was thinking a relay would work but the battery would hold the coil open when the charger is removed.

 

How do I keep the port from being an open circuit when it is not plugged and being charged?

Why do you care about the status of an used port?

My battery charger senses a small voltage and won't turn on the charging unless it sees that voltage. This prevents a short from happening when you inadvertently touch the cables together.

 

the port is exposed to the elements so I want to keep it from shorting if any water or material ended up in it.

 

Put an output switch on the charger?

Even better, but an on/off switch on the mains power to the charger, so it is not using power when nothing is connected.

 

The behavior of my store-bought charger sounds like what you need. It would be easy to rig a comparator to control a relay to cut power if the output sees less than, say, 2V. You could even consider a small wall-wart power supply to control the circuit, so that it could cut off AC power as RB suggested

But, why not just buy a proper charger?