Simple Question on Charging

[Sunyata197]

Hi. I just bought a S2 9.2a..not that THAT is important, and it came with a 12V Adler Barbour Refrig. Now, when I am dockside and plugged in and want the refrig on for the weekend..do I keep my A/C battery switch "on" and if so, do I keep the panel switch selected to the "house" battery, or "all" or ? It seems if I do, the batter or batteries peg way to the right when tested.
OR, do I keep the charger off and let the house battery deplete and then recharge? As you can tell, i am a newbie...

[hellosailor]

Run it on AC. Your batteries have a limited cycle life, you can only deplete and recharge them so many times, so using them up when there's AC available is a total waste. When the AC is on your battery test switch is showing the voltage from the battery charger, that's why it pegs all the way to high scale.

[djmarchand]

Hellosailor is absolutely correct. Keep the charger plugged in. Modern shore power chargers will not harm batteries and as he said there are only so many cycles available in a deep cycle battery. Don't waste them at the dock.

David

[Bash]

congratulations on the new boat.

As to the question of whether to leave the selector to ALL or HOUSE, your boat is probably wired with a battery combiner so that all batteries will charge regardless of where the switch is set. You can check this easily with a voltage meeter by selecting HOUSE and testing all batteries while charging. If they all show charging voltage, you have a combiner working.

[Sunyata197]

The charger is an older one..perhaps 1981 or? I forget the name but it looks older and I remember it doesn't have any cool little tags on it that says "smart charger: or anything. As the refrig is "12V" only, is the juice coming from the batteries, and the charger is replenishing? When I switch the A/C off, the batteries peg to the right. Is that good? Also..maybe a different thread..I noticed that when I put the selector to the "start" position (which I think is labeled "battery 2) I heard a buzzer go off about 15 minutes apart. The sound lasted about 1 or 2 seconds. Scared me. I then never put the selector switch to that selection again and have never heard the sound again...

[Bash]

Don't guess on this stuff. The best first step would be to draw a schematic after tracing each circuit. Pay particular attention to selenoids, should you find any, because those may work as a combiner.

Same thing with your charger. Write down the name and the model number, and then google it until you find it. If it's not a three-phase smart charger, a replacement would be a good investment because it will pay for itself in terms of increased battery life.

This is the downside of purchasing a boat: discovering wire by wire, hose by hose, and line by line what you've just bought. While you're at it, inspect every block, every shackle, and every shroud. Double check every thru-hull and every hose clamp. The confidence you gain in your vessel, and your ability as its master, will be worth the effort.

[Sunyata197]

Thanks all, I will research it more.

[Andina Marie]

When there is no choice but to run from 12 volts, each cycle of the refrigerator will ususlly need more current than the shore power charger can supply so a small amount of charge is taken from the batteries. This is then replaced by the charger during the off cycle of the frig.

This "short cycling" at exactly the same place on the batteries can considerably reduce battery life. If you plan long term periods at the dock, rather than destroy a $1,000 battery bank (as I did) there is a much better solution.

Get any cheap battery from Walmart. Disconnect your house bank and substitute the cheap battery. It doesn't need much capacity since it is supported by the charger and short cycling is only destroying a $50 battery that has a replacement warranty!.

Once a month re-connect the house bank to keep it fully charged and rady for use when you leave the dock. To make it convenient I installed the "sacrifice" battery permanently with a $20 disconnect switch to the main battery bank that I close when leaving the dock.

[Pete7]

Andina, for once I am going to disagree with you, although I hear what your saying. I don't think the S2 is going to have a $1000 house bank, more like 2 x 110 AH joined together, tops.

I would follow the suggestion by Bash to trace what you have and google the battery charger. However, a new smart charger could be a good investment and would act as a power supply to the domestics when on shore power.

There are many different views on batteries and several weeks of reading for you on CF when you have a moment, but I hold this view point about batteries:

Sterling Power Products: What is the best battery to use for an auxiliary charging system?

Sunyata, nice boat by the way

[goboatingnow]

Andina is right that short cycling is a major factor in battery life and is often overlooked. In larger banks its not a problem, but in small banks with weak chargers its a major source of premature battery failure.

IN reality with a small bank you should ensure your charger is capable of running any device that is left on continuously, the fridge being a prime example.

Dave

[Stu Jackson]

Good advice here.

1. If you have a way old charger, especially if it has an ammeter on it, you should seriously consider getting rid of it and buying a new one. Why? 'Cuz it is killing your expensive batteries. A few hundred dollars or maybe less for a quality new three stage charger will provide an almost immediate ROI, since you will be saving the cost of replacing your expensive batteries.

2. Agree about drawing a wiring diagram. Here are some hints about how boats CAN be wired. "Assuming" that you have a battery combiner makes little sense. Don't assume, find out. My PO left me with a pretty good overall electrical diagram, which, when investigated, turned out to be wrong!

Basic Battery Wiring Diagrams This is a very good basic primer for boat system wiring: Basic Battery Wiring Diagrams [added 9/21/11]

[added 1/31/2012] This is another very good basic primer for boat system wiring: The 1-2-B Switch by Maine Sail (brings together a lot of what this subject is all about)
1/BOTH/2/OFF Switches Thoughts & Musings - SailboatOwners.com

**********

You can do some more wandering around here if you're interested:
Electrical Systems 101

[hellosailor]

Stu-
"Assuming". Oh yeah. First time I met a boat that had a ZapStop installed on the alternator, when we finally figured out what it was, it was suspended in space and wrapped in electrical tape. And most people would leave it at that.
As long as the alternator was coming out and the wiring being replaced, I unwrapped the tape and found that BOTH wires had broken off the diode (which is what happens when you install things in the middle of nowhere) and in fact the Zaptop was now an imaginary creature.

Gotta agree with you. Trace, test, diagram everything. Or do it the easy way, stay ashore and play golf.

[Stu Jackson]

Yup. And Maine Sail makes a good point about Zap Stops: they are ONE TIME USE devices and you simply never know if they're dead already. The purpose of zap stops is to avoid frying alternator diodes if the AO is interrupted.

The REAL answer to avoid that, and to avoid ever needing or having to use a zap stop, is to follow the suggestions in my last post and get the AO off the C post of the 1-2-B switch! If you run the AO to the house bank, and make the switch a "use" switch instead of a "charging" switch, you can even turn the switch off without harming anything! Really!!!

To the OP, good luck in your wire tracing. Suggestion: while you're drawing diagrams, also label all of the wires at each end as you identify them. Makes life much simpler.

[hellosailor]

"And Maine Sail makes a good point about Zap Stops: they are ONE TIME USE devices "
Where does he say that? And why should a diode be a one-use device? Unless you blow it up, it will work again and again.

[Stu Jackson]

Somewhere in his multiple electrical system posts on www.sailboatowners.com, I just tried a search but couldn't find it.

Once it blows, it's a goner. Really. And if you move the AO off the C post of the switch and run it to your house bank, you'll never need it again.

From this:

Transient Spike Protector (Zap Stop) - e Marine Systems

It says:

Product Description

TSP-12 and TSP-24 spike protectors build in an additional level of system safety by ensuring an exit corridor to ground should an AC or DC spike invade the vessel’s charging system. The TSP’s fused sacrificial diodes are designed to fail before alternator diodes can be damaged.