It is a common problem. I have melted a couple myself.
I use Sutars brand cig lighter connectors. These are marine
rated and are supposed to cope with 20A, but I think that is a bit optimistic.
Usually it is the male end that melts. I think the problem is the computer power supplies are designed on the assumption that they will be used in a car. Here the voltage is kept at a constant 13.8v by the alternator
. On a boat system the voltage can be significantly less which increases the current and heat.
Using the best quality female boat sockets with thick wiring is a big help, but I would still be a bit cautious, especially in hot weather
The maximium current and hence heat will be when the boat battery
voltage is low (ie not charging
etc), the computer is on with full screen
brightness and the computer battery
is at a low state of charge.
The best solution is to cut off the cig lighter plug and use something else. Anderson plugs/sockets are great. They will handle a genuine 50A are polarised and have silver plated contacts which keeps the resistance low in a salt water environment
. They will accept large diameter cable. Anderson plugs are not very attractive so they need to fitted out of the way under tables, but they will safely provide a high powered socket that will run not just computer power supplies, but spotlights, a wandering emergancy bilge pump
I have a couple of these for high powered devices. You need to cut off the male cig lighter plug and replace it with Anderson plug. Be careful there may be a fuse in cig lighter plug which will be lost
. Make sure you have a suitable fuse to the socket if this is the case.
I also made an Anderson to cig lighter adapter (see photo
which also shows when an Anderson socket looks like) so a can use the sockets as a conventional cig lighter socket. I currently have 12 cig lighter sockets on board which you would think should be sufficient, but the number of devices that use these seems to be ever growing.
Usually the 12v DC to DC use about 20% less power than a small inverter and AC to DC converter. So it is worth getting a 12v system that works and is safe.