Modern Vespa

As you know yourban 300ie 2014 doesn't have 12v power outlet.Is there chance to use some unused fuse, may be for heated grip or I don't know to add something like this
https://www.amazon.com/corriente-volt%C3%ADmetro-interruptor-alimentaci%C3%B3n-adaptador/dp/B0B1WJ3W5X/ref=mp_s_a_1_1_sspa?dib=eyJ2IjoiMSJ9.qmoEnzgqQBZi0rI346xW9f1fmY3f69I55c9TscchgrMUVBqbC2ySraPEZoDVNhwrU2ZzvxnFWmVxocK9m9RRYy8fjDKF565G2p1zFE-x_-nQRj6min8I2tPfRPqYxdjoD_KjPZfvqJ9WNBnzfRSFWUxQYnPwxcVcWuUcIBVHgzjToa0ylMS-JR_8Jye6_KabtpExJ8u6ALxPDhANqQxZGw.lwGbDXmQ-SX9m9RsSbSDwNIzYgrwhqGPLbqiFgns3mU&dib_tag=se&keywords=12+volt+power+outlet&qid=1739890855&sr=8-1-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9waG9uZV9zZWFyY2hfYXRm&psc=1

If it is not going to be used regularly, then it is probably best to use a adapter such as Optimate to your battery trickle charger connector. See link

Fwiw, in my experience heated gloves work much better than heated grips without the need for wiring

https://optimate1.com/product/cbleo-06/l

You mean to use something like this
https://optimate1.com/product/usbo-118/?wcmlc=EUR

I think to use some unused fuse, that I mean for heated grips(I don't have it and fuse is maybe free for use)

You asked for a unfused 12V power socket, and that is what I linked.

Your last response is for a USB-C charge port

Apples and oranges difference.

You have to determine what exactly you need

Sorry I didn't explain correctly.I need USB charge port or 12v car socket, I will used it for charging my phone.

Ok, that makes more sense.

Now you need to determine if you need a conventional USB-A or the newer USB-C socket.

For USB-A, you need O-108. Note: with this kit you will also need O-01 unless your bike already has a SAE trickle charger connector.

https://optimate1.com/product/usbo-108/

If you need USB-C then O-118 is the correct choice and already includes the O-01

In my experience which is over 50 yrs of racing and riding. heated grips are the better option over gloves. Gloves are bulky and you can forget to bring them, the batteries require charging.
Grips always on the scooter, never leave home with out them. turn on /off at will.

I added a mini switched fuse block rather than tap into the bikes electrical system. This connects directly to the battery and provides 4 x 5amp fused circuits to connect USB ports, heated gear, lights, or accessories with minimal disruption to the bikes primary electrical system.

The only tap into the electrical system that is required is something to an ignition activated circuit so the box is powered only when the key is in the bike to avoid power drain. I tapped into the old USB circuit as the relay-activation on my old MP3 as it was low-amp, low risk, and linked to the ignition key. You can use wire-taps to make the connection rather than risk cutting or soldering wires.

4 x 5amp switched fuse
https://www.amazon.com/gp/product/B0CLJG1J2T

Wire-taps, low risk, durable, reliable
https://www.amazon.com/gp/product/B004D0C2RC

Thats look very nice and is open for new upgrades because there is 4 circuits for use, but where I need to attach acc positive wire?

The idea in all this things is that you have + and - direct from the battery, and if you like to be sure the things connected only works as you pass your key then connect the ACC cable to any circuit that don't have power if the bike is without key engaged. The advantage is that this cable don't use load only a minimum to activate the relay for the real source from the battery.

If you like that always the things connected have power (with or without key engaged) you connect the ACC cable to the + of the battery and that is all.

A running light circuit would do fine for the ACC with a wire-tap would be an easy activation method for the relay. Low amps, low risk, only on with the engine so the switched-relay will only be on with the bike running. When I installed mine, I used hot-glue around the connections to the block to improve weather resistance and tape over any unused ports.

You can attach the USB port to this device. You may have to trim and solder the wire-ends to fit into the fuse blocks connection points, but thats easy.

12V accessory plug can be tapped into it then any plug-in USB would work.
https://www.amazon.com/Cigarette-Motorcycle-Receptacle-Waterproof-ZHSMS/dp/B07H1MGWFN?th=1

Dedicated plug but not as flexible as a blank 12V socket.
https://www.amazon.com/12V-USB-Outlet-Charger-Socket/dp/B09SKXX1J9

Thanks a lot!Running lights circuit to attach, it's a very good idea, then the USB will work only on running engine and thats is OK for
me.

Tapping and splicing, especially into existing circuits, is a sign of pure amateur hour.

Get a switched fuse block or use the Optimate I linked above. It has a timer to shut off the USB port 1 hour after ignition is shut off eliminating the need for a switched connection. Just connect to battery and done.

In addition, it has a integrated battery monitor and provides a trickle charger connection point

Maybe you are right I follow your advice!