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Battery Charger and Battery Switch

7K views 11 replies 5 participants last post by  Maine Sail 
#1 ·
I am ready to start my education on my battery charger. I have a starter battery and two house batteries - all 4D. I have a Guest 2530A charger. There is only one red light titled "DC Power Available."

The charger never shuts off. My house batteries were drained down to 4.3V the other night (that may be a different discussion), so I plugged in the charger and connected to one of the house battery terminals. It has been charging for 36 hours and still buzzing. Now, the panel voltmeter reads 13.7 or so. (And the switch is on house.) Handheld voltmeter reads 12.89.

First, why the difference in readings?

Is it supposed to stop buzzing? The charger says finished charge at 13.8V and it is there or very close according to panel voltmeter.

Is 36 hours an obscene amount of time to charge?

Can I check the water lever while it is charging?

The batteries don't feel hot and they are obviously not boiling over. Is it dangerous to keep charging them?

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Wiring charger to the battery switch.

The negative is grounded - no problem there. Intuition tells me to wire the positive to the "Both" terminal on the battery. That way I could charge the starter batt or the house batts or both. The alternator feeds the starter, then to the "Both" terminal. But for some reason, during one of those half conversations with my mechanic, he said I should wire in to the "House" terminal so that I could charge the house or both.

What is the proper terminal on the battery switch for the battery charger?
 

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#2 ·
Ok, I see a problem here. You say that the positive lead from your batteries go to "both" pole on the switch. That should not be. Your house batteries should be wired as such:

Negative pole on battery 1 to negative pole on battery 2 to ground (most likely on engine). Positive pole on battery 1 to positive pole on battery 2 to battery 1 positive pole on switch.

Your starter battery should have its positive pole connected to the battery 2 positive pole on switch and its negative should be connected to the ground.

In this fashion, you can start from battery 1, 2, or both. You can charge battery 1, 2, or both as well.

I would change this immediately.

Tod
 
#3 ·
No no. Sorry if I misled. Starter battery is connected to 1 post on switch. House batteries connected to 2 post on switch. The alternator - via the starter - is connected to BOTH post on switch.

I think the question you are addressing is which post do I connect the charger to?
 
#6 ·
My bad. The jumped to the conclusion that the post labels would more closely coincide with the position labels. But they are 1, 2, & COMMON actually, since we are splitting hairs. 1,2, & COMMON on the back. OFF, 1, 2, BOTH on the front. Exactly the way I would have designed it. But everybody can call it whatever they wish so long as it is clear when they are referring to the post that accesses both battery banks.

Now that the vernacular lesson has been learned and I've made atonements, can anyone advise me on my questions?
 
#7 ·
But everybody can call it whatever they wish so long as it is clear when they are referring to the post that accesses both battery banks.

Now that the vernacular lesson has been learned and I've made atonements, can anyone advise me on my questions?
Do you call your cunningham your halyard or your jib sheets your downhaul?

C'mon.

Vernacular? Splitting hairs? Malarkey. WADR, specificity does help...;)

We ARE trying to help you.

That said, you may be interested in these:

OEM 1-2-B Switch Wiring History Alternator/Batteries & "The Basic" 1-2-B Switch BEST Wiring Diagrams

Basic Battery Wiring Diagrams This is a very good basic primer for boat system wiring: Basic Battery Wiring Diagrams

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
 
#8 ·
FYI, I had a friend who made the same assumptions you made. He found, after four years or so with his boat, that not only was his alternator not working properly, but his batteries were not being charged.

All it would have taken, was, as we'd suggested, that he trace his wires from the batteries to the switch.

He finally did. Batteries and a factory (?) mis-wired battery selector switch

Really, don't take it personally, but "call a spade a spade" usually works.

As far as the positions and posts on the switch, many of us have had the very same misunderstanding. Me, too. :eek::mad::):):)

Good luck.
 
#9 ·
Lobo, I'd suggest "divide and conquer".

Break up the system and examine each piece to see which one is bad. Fix the bad ite, then come back to look at the system for system faults.

So first, pull the battery cables and test the voltage on each battery using a known good voltmeter. Ah, "known good". Yes, it is possible that your handheld iff off, or the panel meter is off. I've seen panel meters off by more than two volts, handheld digitals often off by 1/2 volt on a 12-20 volt scale. I got so tired of this nonsense that I went out and built a meter calibration reference gizmo, it puts out 10 volts within better than 1/100th of a volt and if the meter doesn't agree--I know the meter is wrong. In your case the simplest thing might be to go to WalMart or Target and spend $25 on a new meter, two out of the three will probably come close to agreeing.

Also, if you are testing voltage while any charger/alternator is running, you may be seeing an error if there is AC leakage or some type of pulsed DC on the line. Take your readings with JUST battery power connected, see if there's a difference.

If the batteries are OK, they'll range from 12.6 (perfect) to 11.6 (useless) depending on condition and state of charge, after they've been allowed to sit unused overnight, or after a short load (turn on everything for two minutes, then turn it off and rest for five more) has been applied. That's not perfect but it is good enough for now.

If the batteries are OK then you need to check the charger, which can be harder. You'd need to check the output for proper voltage under load, and for any AC leaking through. Often the best way to check out a charger is to first check your battteries, then if the batteries are OK, see if the charger is working. Swap it out with a cheap battery charger, even an auto battery charger, and see if that works when the boat's charger doesn't. If the other charger works, time to send the suspected one out for testing and repair.

And of course sometimes you get lucky. If you take a pencil and sketch out the wiring of the system, and clean and tighten all the connections, sometimes that's all it tkaes to find one loose, dirty, or wrong connection that fixes everything. If you're lucky.

But you still might want to "divide and conquer". Start with the batteries, you can also take them into any battery store and have them tested if you want to make the job easy. (Except for the heavy lifting of course.)
 
#10 · (Edited)
I am ready to start my education on my battery charger. I have a starter battery and two house batteries - all 4D. I have a Guest 2530A charger. There is only one red light titled "DC Power Available."
That is an an older ferroresonant charger from the late 80's / early 90's. They do make a humming noise. The problem with them is FR chargers have a tough time doing finishing charges and float stages. They need to switch on and off because they don't do very low currents well. The newer switch mode chargers handle low current output far better and can be left on for weeks or months on end where a low end FR tends to not do nice things when left on for long periods..

The charger never shuts off. My house batteries were drained down to 4.3V the other night (that may be a different discussion), so I plugged in the charger and connected to one of the house battery terminals. It has been charging for 36 hours and still buzzing. Now, the panel voltmeter reads 13.7 or so. (And the switch is on house.) Handheld voltmeter reads 12.89.
They are not intended to shut off but instead go into "float mode" where they maintain a lower voltage. Many older chargers don't do this stage as well as newer ones and with an FR charger you will likely hear it humming along..

First, why the difference in readings?
Analog panel volt meters can be notoriously inaccurate. We also don't know where it is sensing voltage or where your charger ties in or what the voltage drop may be in the system. The only reading that matters is at the batteries. 12.89 is barely above static resting voltage for a full bank? What was the voltage with the system loads off?.....

Is it supposed to stop buzzing? The charger says finished charge at 13.8V and it is there or very close according to panel voltmeter.
It likely won't stop buzzing....

Is 36 hours an obscene amount of time to charge?
Yes but you should be in float not bulk or absorption so the buzzing is likely normal for that charger even in float.

Can I check the water lever while it is charging?
Usually best to check it when they are resting. Heat can cause the electrolyte to expand slightly and make them look more full than they are. Should be about 1/8" below the lower edge of the fill "well" but not touching the well at all..

The batteries don't feel hot and they are obviously not boiling over. Is it dangerous to keep charging them?
I am not a fan of leaving an FR chargers on charge any longer than is necessary. With a newer switch mode charger that's fine but with many older chargers I feel it an be safer to err on the side of caution.

----------------
Wiring charger to the battery switch.

The negative is grounded - no problem there. Intuition tells me to wire the positive to the "Both" terminal on the battery. That way I could charge the starter batt or the house batts or both. The alternator feeds the starter, then to the "Both" terminal. But for some reason, during one of those half conversations with my mechanic, he said I should wire in to the "House" terminal so that I could charge the house or both.
I would not advise that. This means you will need to leave the battery switch in the ON or BOTH position when you leave the boat and also introduce a few more connection points to corrode and cause voltage drop. A better approach would be to get a newer switch mode charger with dual outputs or add an ACR (voltage sensitive combining relay) or an Echo charger. You then run the charger direct to the house bank and the automatic charge managing device takes over keeping the second bank charged.

What is the proper terminal on the battery switch for the battery charger?
None for me, but if you have to, direct to the #1 or #2 post. If not willing to invest in a new charger or a charge managing device then you will need to go to the "C" post and leave it set to BOTH, or what ever bank you want charged.
 
#11 ·
My two most recent posts haven't shown up here. Thanks everyone for the information. Wasn't meant to be personal Stu - just banter. You are right and I've made the mental correction. HS divide and conquer is my overall strategy. The batteries are new and I tested them since your post. From MS post, a new charger has made my short list.

Thanks again everybody.
 
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