Water proof charging contacts

[zoro]

Hi, my fellow peers.

Although I have been following Dave on youtube for a while, this is my first post on the forum.

I have a question, which most likely has been asked somewhere here that eludes me.

I am busy playing around with a small handheld size device (essentially used for data logging) that I would like the be made out of impact-resistant plastic of aluminium. It will house a small PCB and battery. It needs to be waterproof. Similar devices have been known to be thrown into a kettle to be boiled on a number of occasions, so I would like this one to be able to withstand that.

My problem is that I need a way of charging the device. Possibly of some sort of basic data interface as well, does not have to be high speed.

Does anyone have any recommendations on an electrical contact system that is small enough (diameter of around 20mm max for the complete contact housing) that I could experiment with?

Seeing as this is just for a hobby project and something I want to muck around with, I am going my wise (and perhaps not so wise ) way and go for a DIY solution rather than an off the shelf solution.

Any suggestions?

Cheers!