I have 5 lighter receptacles, one in the bow and one in cockpit
, one at the Nav desk and I have installed two in the fwd Stateroom to run our CPAP machines.
The one in the bow and cockpit
I think were factory installs, if so that makes them 30 yrs old and they work.
Lighter receptacles are bad about what you plug into them not keeping a good contact, and contrary to what you would think, I don't think you can pull significant amps through them, things like portable coolers are better off using a "real" plug etc. But for USB chargers I have found them to work fine, the one beside the chart table I have a four USB charger plugged into it most of the time, and when we are away from the boat
I plug in an air Purifier, something that I feel I may have wasted money
on, I don't think it does much really