Excerpted from the earlier discussion at:
12V DC Receptacles (Outlets)
I’ve never been happy with the normally available 12VDC outlets (receptacles) - not the W.P. Bi-Pin Deck
Connections (Perko 1189 Series, Cole-Hersey M121-BP, SeaFit, & etc), and especially not the Lighter Socket type (commonly fitted to accessories).
For 12 Volt DC accessories, I use “Midget Twist-Lock Devices” (2 Pole, 2 Wire, Polarized, NEMA Code ML-1), such as the:
Hubbell #HBL7526C Flanged Receptacle (or Cooper
Standard Weather-Proof Coverplates are readily available available.
mated with the
Hubbell #HBL7545C Plug
(male cord cap) (or Cooper
The series even has a female cord cap (to make an extension cord) #HBL7506C (or Cooper #7464N etc.)
Although these devices are intended for AC use (UL rated for 15A 125VAC - polarized), they are an excellent alternative to the conventional DC outlets.
They are rugged, corrosion
resistant, easily installed, attractive, and best of all “Twist-Lock”.
Not normally available at Marine
stores, these NEMA type "ML-1" Midget devices are available at any good Electrical
(or Industrial) Distribution Supply house.
Unfortunately they are more expensive that the inadequate devices they replace.