Professional BoatBuilder - December-January 2018

44 PROFESSIONAL BOATBUILDER

SYSTEMS: Battery Technology

marina and inspect the shore-power

pedestals, you will see signs of burning,

which is also found if you look at the

two ends of shore-power cords. We are

ever more o en pushing these circuits

to continuous high-current levels for

which they are not well suited. At the

boat end there is a connection available

from SmartPlug in Seattle, Washing-

ton, that takes care of the connection

issues (see Parting Shot, PBB No. 134,

page 80). Other than this, the only

antidote is to be aware of the problem,

not to push the shore-power cord to its

rated current for extended periods of

time, and to regularly inspect the con-

nections at both its ends, and on the

dock and the boat.

Imperfect Connections

Ideally, we should have bolted con-

nections wherever we have high cur-

rents. But even here we run into

another potential problem. On boats,

melted down the dockside outlet.

 e problem here is that shore-

power cords have friction-type connec-

tors at both ends, instead of the bolted

connections normally on high-current

circuits. If you go around any large

I had a 3.5-kW battery charger that

would have run at full output for

hours if I had let it, but instead I

derated it to 2.8 kW (around 80% of

the shore-power outlet rating) to pro-

tect the shore-power circuit. I still

The friction-type connectors available at

most marinas aren’t suitable for high-

current circuits, which ideally should

be hooked up to bolted connections.

In any large marina, you’ll see signs

of burning on shore-power cords

(above) and pedestals (right).

Batteries170-ADFinal.indd 44 11/3/17 10:36 AM