Where's the ground?

Joe11688 · Oct 13, 2009

emergpa1 said:
I am trying to repair and replace wiring on my boat. I ran across a question I couldn't find the answer to in "Sailboat Electrics simplified" by D Casey.
He says to attach the negative battery post to the engine block. Of course most of us with motors hanging off the transom have no engine block. My outboard is usually out of the water. Do you guys connect your battery ground to your outboard? If not then where?
Also, what kind of charger do you use for a deep cycle marine battery? The po on my boat had it on a trickle charger. The batter will not accept a charge now and it is only about 2 years old. Did this type of charger ruin the battery?
Thanks
Keith

Keith,
You can disregard grounding to your outboard if you have no provision for it. I have a duplex coming from the charging system on my outboard to my battery, but other than that your battery doesn't need to be grounded to anything. If you had an inboard gas engine, the ground would be needed for the starter, alternator, and the ignition system. This is why he mentions it in his book. As far as the battery charger is concerned, you need a deep cycle battery charger for deep cycle batteries. I have one that I bought at Wal-Mart called "Ship 'n shore". It's a 10 Amp fully automatic charger for Deep Cycle/Marine Batteries, 12 Volt. I take my battery out of my boat and store it down the cellar for the winter and I hook it up to a small charger that automatically maintains the battery throughout the winter months. It's a small charger and made by "Vector". It's called Vector Smart 2 Amp fully automatic 12 v battery charger, float mode maintainer. It's for deep cycle batteries, and you can buy it at Lowe's. Your old battery can be tested to find out whether it's good or not. If it's no good, I would buy a new deep cycle battery with at least 100 Amp Hours capacity.
Joe

Joe11688 · Oct 14, 2009

emergpa1 said:
Thanks joe,
Regarding the ship n shore charger, is that the one you keep on the boat? Do you plug it in at the dock to keep your battery charged while there, or do you use it at home.
Can you tell me about the charging system on your outboard?
I guess what i am asking is, if I am camping out on my boat, but in a slip that has shore power, but i want to used my dc fixtures, what type of charger should i have keeping my batteries charged. If I understand you correctly, that is where you use your ship n shore charger.
thanks
keith

Hi Keith,
No, the Ship 'n Shore charger is a self contained charger that I keep at the house and bring it down to the boat when the battery needed charging. I have another battery charger that looks exactly like that one and is probably made by the same company. It's a trickle charger for automotive batteries. The the S 'n S charger was used at the club dock at high tide, with a long extension cord. To tell you the truth Keith, I haven't used the S 'n S charger in a couple of years now since I increased the size of the conductors from my charging system on my outboard but keep in mind, I only use my radio occasionally and I'm running my autopilot most of the time. My autopilot only uses X amount of milliamperes. I rarely sail at night and I have four AAA battery type LED lights in the cabin and use candles most of the time at night. If I were you, I'd buy a built in charger and wire it up to your electric system so that you can just plug an AC cord into it at the dock. I can't seem to find my Johnson 8 hp manual, so I'm not sure about the type of charging system it has on it or the output. My friend Wayne told me that these small outboards don't have alternators. They have a charging system that works off the magneto. I think that the output is about 4.5 Amps but I'm not sure. Like I said, I don't use a lot of house power. I have a cheap little AM/FM radio that runs on four "C" batteries that lasts the whole season. I do a lot of overnighters in the summer months and my battery seems to stay charged when I use my outboard occasionally. You may want to buy a solar collector. Wayne has one on his Seaward 22 and he mounted it on the house roof just to the right of his companionway. He has it raised up a little with fiber washers to dissipate the heat on a hot day, so that it isn't laying on the roof.
Joe

Raftco · Oct 14, 2009

Keith -

What type of outboard are you running? I just added an alternator & charging system to my 9.9hp Mercury that maintains the battery. Cost was roughly $120 for the kit. The ground for the engine is on the battery with the positive & negative battery cables, no need to create an additional ground.

When you're talking about maintaining power, using extension cords and an off the shelf battery charger you're getting into a sketchy situation when your boat is floating. Most of those chargers are meant to be in the garage and can short out if they get wet, you're playing with 120volt power and you need to make sure that use the appropriate equipment or you could kill yourself. Think of a hairdryer falling into a bathtub...
I always pull the batteries out and charge them out of the boat if using a plug in trickle charger. You can check each cell independently with a battery syphon that will tell you if a cell is dead, if not just make sure the cell has the appropriate level of distilled water in it and put it on a charge overnight. With commercial use, I generally get about 3 years out of a battery before it dies.

Additionally, an extension cord that you buy from Home Depot or Lowes isn't made to withstand the corrosion from salt and they are also not insulated properly for marine use. Many marinas will not allow you to use that type of setup if your boat is in the water - on land is a different thing. I'm not sure where you're sailing, maybe it's different there - but remember, a DC system is a lot less dangerous than an AC system and if you plan to hook up to AC power you best install a proper shore power system.

Here is a good instructional video on Shore Power

I would recommend looking into solar power, there are some great topics in the forum regarding solar power if you do a search. The best setup I've seen so far is the "Sunsei Solar Grips" that can easily mount to your stern pulpit and with the right panels you'll trickle charge the batteries with no problems. You can also adjust the pitch to aim them at the sun as the day progresses or leave them fixed while you are off the boat to keep the batteries topped off. I'll be hooking this system up, the same as the photos in the bottom of the post: Solar Battery Charging topic

If you look around, you can find solar panels pretty cheap: Here is a link to Cheap Solar Panels and Here is a great video on solar power options

I also use the small LED stick on lights like Joe and I replaced 1/2 the lights in the cabin with LED's hardwired. That along will save your batteries a lot if you aren't running interior lights or if you switch your lights to LED's, they use significantly less power.

Most of the info I found via searching this forum and watching the educational videos on westmarine.com, if you search for an item like "solar" they generally have a video that corresponds to the product which is very helpful.

Good luck!

Joe11688 · Oct 14, 2009

Keith,
This vector float mode maintainer that I told you about is for maintaining your battery over the winter months down your cellar or in your garage. I'm taking it for granted that you pull your battery out of your boat at the end of the season like I do, and store it inside. Our club dock is over 110' long and we have a GFI weatherproof outlet near the ramp for the guys to work on their boats or charge their batteries if need be. Most of the guys only use this outlet for the time that they are there working on their boats. Naturally, AC is dangerous. Also, it's true that water and electricity don't mix. I was a power company lineman for 32 years and I know this. So you take special precautions. When I charged my battery years ago, I put my charger inside the cabin and hooked it up to the battery. Then I connected a 100' heavy duty power cord to the charger and ran it up to the outlet on the dock. Then I plugged it into the GFI outlet. I was able to do it at the dock with the boat close to the ramp and bulkhead. It was a lot easier than removing my battery, and a whole lot cheaper than buying a 30 or 50 Amp shore power outlet with the various length cords. I've been using Delco Energizer deep cycle marine batteries and have been getting at least 5 years out of them. I had one that lasted 7 years. If you take good care of them, they'll last. I think that a charging system on your outboard and a solar collector is the way to go for you, but if you want that battery to last during the off season, the float mode maintainer is the way to go with the battery stored in your garage or cellar.
Joe

Joe11688 · Oct 15, 2009

emergpa1 said:
Joe, an interesting note, when we were getting a heavy rain i climbed into the boat, and into the hold underneath my cockpit just to see if was were getting any leaks. I found a new leak i didn't know about. It was coming from the defunct but still installed round analog depth meter. it was mounted on the starboard side of the cockpit and the water was fairly pouring in....right onto the circuit breaker box for the ac shore power, over the outlet, and into the bilge. if lynn and i had of used that sink or been plugged onto shore power while sleeping at our slip at the club during a heavy rain, we could very well have been electrocuted. the affected outlet was the one over the galley sink
keith

Keith,
It's a lucky thing that you found that one, but that's the only way that you're going to find all these leaks is to go into the cabin on a rainy day and scout them out. That boat shouldn't leak a drop. As far as using your boat for a camper goes; I've been doing that for years. I love hanging out on my boat at anchor in a favorite cove. I'm not in favor of slips or hanging out on moorings. I like the Boonies and shallow waters for hanging out. As far as the electrical goes; I like to keep it simple with the bare necessities. Good luck!
Joe