Marina 30 amp service to battery charger

Grazer

Hello all,

I think I have an easy question, but I am not sure since my boat does not have shore power. It does have a battery charger system that is usually plugged into my 120 service at home, but I would like to charge it up at the local marina once the boat is in the water. The marina has a 30 amp service. Is it as simple as using a 30 amp RV male connector to a 15 amp female connector and plug extension cord straight into my charging system? One of these units:

or one of these:
http://www.campingworld.com/shopping/item/power-grip-adapter-30a-male-to-15a-female/27985
Any suggestions would be great.
Thanks,
Grazer

JamesTXSD · Posted: Thu Jun 16, 2016 9:39 am Post subject:

No, not that simple. Your marina will likely have a marine 30 amp service pedestal, which will have a different (from RV type) shape 3 prong male that has a twist fit...

Most RV parks have 50/30/15 amp service, most marinas have 30 amp (no 15) that require the above 3 prong connection. It would probably be best to get something that has a GFCI built in to protect your boat.

thataway · Posted: Thu Jun 16, 2016 5:54 pm Post subject:

Gazer the first photo you showed is an RV 50 to 30 and 15, I believe. There are several 50 amp marine connectors, but you are far more likely to find 30 amps.

Some marinas have 15 and 20 amp, as well as 30 amp and the larger boat 50 amp circuits. My slip at Hooton Island probably had the only 20 amp plug in the marina--and I didn't bring my adaptor. I keep the Marine 30 amp to 15 amp adaptor always on the boat. I also have a 20 and 50, which I take when going on long trips. Often the 50 amp adaptor will give 2 30 amp circuits.

I would get the 30 to 15 amp adaptor:

gulfcoast john · Posted: Thu Jun 16, 2016 6:43 pm Post subject:

Gazer, agree with Bob with a couple of observations:
Your on-board battery charger should be rated for marine use. There are a few ancient ferroresonant car chargers that aren't appropriate for boats. I doubt this is an issue, but just in case.
Bob's pic looks like it might include a GFI at the dock pedestal. Unlike him and James, I have had some issues with that setup causing nuisance tripping if you also have an on-board galvanic isolator, even tho all the circuits AFTER that have GFI protection built in. I don't know if the 22 usually has a galvanic isolator or not (has to do with preventing stray DC currents in the AC system from eating your zincs...or something like that). Again, probably not an issue, but this would be cheaper without the un-needed pedestal GFI:

https://www.amazon.com/Conntek-Locking-Adapter-Straight-Connector/dp/B001H9TSEW/ref=pd_sbs_263_4?ie=UTF8&dpID=31U6MGwXABL&dpSrc=sims&preST=_AC_UL160_SR160%2C160_&refRID=2C7T7ZXRP8Y27ZZF7BEJ

We use this adapter on the dock to use our toaster oven, so it doesn't smell up or heat up the boat. It's not water resistant with locking collar etc but no 15/20A adapter is. Be careful.
Happy Boating!
John

Grazer · Posted: Thu Jun 16, 2016 11:33 pm Post subject:

Thanks for all the responses. I like the adaptor that Bob depicted. That would serve me well and it looks like it has some sort of GFI protection built in. No, my 22 cruiser does not have a galvanic isolator on board. I only plan to use the charger once in a while when out for extended trips.

colbysmith · Posted: Fri Jun 17, 2016 12:01 am Post subject:

Many Marine outlet stores have simple adapters that are small and have the 30 amp twist male end with 15 amp female on the other side. I just made a new adapter after dropping mine in deep water..... Menards has the 30 amp twist connecters, that I then just attached a 15 amp "pigtail" to it. Colby