I went with a NOCO Genius 3 bank. It has been great for many moons.
We just received a notice from our marina that specifically cautions against 15 amp extension cords from the pedestal to the boat. Our marina has 30 amp service to each sportboat slip. I had used a Marinco adapter plug to go from the breaker outlet to an extension cord to the boat where it would plug into a 15 amp receptacle. Marina did not like that set up. They are advising that extension cords are for temporary use such as for running a power tool while doing in-slip repairs. They cite the risk of fire and that a large portion of boating fires involve extension cords.
Of course, I see quite a few commercial fishing boats in my marina that regularly use 15 amp extension cords while at dock for extended periods and they appear to be using them for living purposes, not temporary repairs...
In any case, I don't want to be the source of any fire. I now run a 30 amp cord from the breaker box to the boat, where I use an adapter to plug into a Marinco inlet that feeds the charger. I haven't asked but I hope this satisfies my marina and I do not have to install a 30 amp inlet plus distribution panel on the boat...
John on Chubasco
Fire Hazards and Risk Factors From Using Household Extension Cords in Harbors and Marinas :
The use of Non-Marine household extension cords to supply shore power to a vessel creates several hazards often overlooked until a problem occurs. The most significant problem is an increased risk of fire when using a small-gauge wire plugged into a 30 or 50 amp receptacle on the dock.
The NEC (National Electric Code) clearly defines the size & type of wiring that must be used for a given size circuit breaker, in order to ensure the breaker will trip off if there is a problem.
There are 3 main issues to consider:
The wire size in the cord must match the size of the circuit breaker the wire is connected to. The dock 30 amp breakers WILL NOT trip if a small 16gauge or 18gauge cord is plugged into it. Even with a small load like a dehumidifier or battery charger, if there is an electrical fault or short circuit at the boat end, the small cord will not carry enough current to turn off the breaker; the cord simply overheats until it catches fire. This has been documented many times as the cause of a catastrophic fire.
The extension cords typically used are not made of corrosion proof materials, all of the prongs, receptacle blades, and even the wires are made from bare copper or plated steel, which quickly corrodes and causes excess heat to form. Even proper marine grade cord fittings suffer from corrosion, house-hold cords fail at a much higher rate.
Most extension cords are not rated for constant outdoor exposure; particularly the outer insulation. While the outer jacket MAY last a year or two, most typically do not, leaving the inner conductors exposed within a relatively short time.
If boatowners want to use an extension cord plugged into a 30 amp dock receptacle, the cord needs to have at least #10AWG conductors. A [30amp to 15 amp] unitized 1 part adapter at
the appliance end can be used to connect the 30 amp cord to the heater or charger. This is considerably safer than using a small cord plugged into a large breaker.
The requirement to prohibit the use of household extension cords has been forced upon both boatowners and harbors by insurance carriers in many cases. In addition, many harbors have been banning the use of [30 amp to 15 amp] or [50 amp to 30 amp] pigtail adapters, for the same reasons noted above. A 30 amp device plugged into a 50 amp breaker will overheat before the breaker trips.
The use of extension cords should be limited to temporary, attended use only, for power tools or other supervised applications; never for unattended or long-term use in a marina.
They’re not wrong. Whatever cord you use, it still has to meet the maximum ampacity requirements for the installed circuit protection, and needs to be constructed of proper materials to avoid degrading. Your setup sounds perfectly fine, as both components are specifically designed to do what you’re asking them to, and as such will be built with appropriately sized components and proper materials.