Is this battery charger dead?

Hello all. We’ve had this boat for 2 years. 2 months ago we got to the boat to find it dead even though the shore power was on and battery charger on. It was hot with red lights. I was able to reset the breaker and let it cool, then it worked great until we left a few days later.

Next trip last month, same deal but batteries were not yet depleted.

This trip, about a week later, again same deal except this time I can’t get the charger back. Did it die? Any idea what would cause this?

I might just run to west marine and grab a new one. Seems easy enough to wire in. Thought I’d ask here first if anyone has seen this before.

Thanks guys.

No experience with one like yours. However with a boat your size, assuming you have a decent size bank, that charger is way undersized. I would not buy another like but go to at least 50 or 60 amps. I like Pronautic chargers. I have 2 of them on my boat. You should also put fuses on each leg going to the battery banks. Blue Seas makes a 3 leg fuse holder for MBRF fuses that works very well for this application. Size the fuses for about 10 amps more than the charger outputs total. For instance if you get a 60 amp charger get 70 or 75 amp fuses because the charger could output the whole 60 amps yo one battery bank if that bank is very depleted.

And if you get a significantly larger charger, pay attention to the wire runs from charger to batteries. The wires need to be sized properly to carry whatever current levels you're aiming for over the distance from charger to batteries.

Our boat came with a 40A ProMariner ProTech-4 charger, mounted not close to the battery banks. I wanted to replace it with a newer ProMariner 60A ProNautic... but the existing wires from the original charger location weren't big enough for that current over that distance.

Plan B was that we installed a ProNautic 60A charger closer to the battery bank and with it's own new properly sized wires...

And we left the original in place and working, so I can use it to sometimes augment the new charger.

-Chris

The ProSport charger manual is online. It will tell you what the lights mean.

Found the manual. I don’t know why it was working great for over 2 years. Maybe my batteries aren’t happy and it’s overloading the undersized charger?

Steve91T said:

Found the manual. I don’t know why it was working great for over 2 years. Maybe my batteries aren’t happy and it’s overloading the undersized charger?

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That wouldn't happen unless there was a short in one of the batteries that was pulling maximum current from the charger so it couldn't do any net charging.

And contrary to the bigger is better philosophy expressed above, it is all dependent on how you use the boat. If you go out on weekends and draw the house batteries down to 50%, then come back to the dock, plug in until next weekend, you only need a small charger. 10A would be fine because you have plenty of time to recharge.

But if you draw your batteries down and want to recharge them quickly with a genset, then size the charger at about 25% of the Ah capacity of the batteries for quick charging. Or if you tie up at the dock overnight after drawing them down but want to go out for several days the next morning, you also need quick charging but probably not 25%. 10% should work fine in that case.

David

Also try giving ProMariner a call. Historically they have been very helpful. I do agree that is kind of a small charger, but that shouldn't be what killed it.
Where is the boat right now? There may be some better alternatives to West Marine. Check Defender as well, they ship pretty quickly.

If a battery is failing it might become overloaded and shut down.
If you have wet cells check them with a hydrometer.

Ok so I had the breaker off all night. This morning I turned it on and the charger had a “ready” light but wouldn’t charge. Left it like that for couple of hours. So I cycle the breaker again and now it has the red “charge” light and is now charging.

I’m going to go take voltages at the batteries and see what I get. But my volt meter for both engine and house batteries were at 11.5 and now is up to 12.5 volts.

Update: I saw 6.1v and 12.1v. But the charger is really hot. So I turned it off.

I’m worried that it’s the batteries. I will admit that earlier this year I discovered that these batteries need water. Never crossed my mind. I thought they were sealed like car batteries. They are all pretty dry. I topped them off with distilled water months ago but I’m afraid the damage is done.

How about a hydrometer test?

How many battery banks and how large is each?

A 20 amp charger is going to take a long time to charge batteries. Running FLA batteries down deeply, repeatedly will kill their duty cycles pretty quickly. As will running them down and not fully charging them. Do you sit mostly on the dock, or on an anchor or mooring?? How many hours do you charge them daily?

I’m getting ready to figure out what I have.

Boat stays plugged into shore power. When we run the boat or at anchor the generator is running because I don’t have an inverter.

Steve91T said:

I’m getting ready to figure out what I have.

Boat stays plugged into shore power. When we run the boat or at anchor the generator is running because I don’t have an inverter.

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What are you running that needs 120VAC while you're underway? It's not your problem, just a bit of a surprise.

Ok I have five 6v batteries and two 12v batteries. All voltages are identical. All 6 volts are reading 5.7 and the 12’s read 11.8. This is with the charger off

5 - six volt batteries is a problem. Either 4 or 6 but not 5. The 6 volts need to be in pairs of 2 in series to make 12 volts. If those voltage readings are at the battery post with a digital volt meter after charging, they are toast.

It is really strange that you have 5 - 6 volt batteries. It looks like that 4 are in series/parallel which is normal but what is the single 6 volt battery doing? Also not in love with the wiring job on the batteries. I would like to see it cleaned up, not a critical issue but it would be much nicer if it was cleaned up and cover all the positive terminals at least. That way if you are in there working and drop a tool across the posts it may not short out. Have you had a certified marine electrician look at your boat? That may be the place to start just to look over the whole boat and check things out and then help you decide what way to go.

Steve91T said:

I’m getting ready to figure out what I have.

Boat stays plugged into shore power. When we run the boat or at anchor the generator is running because I don’t have an inverter.

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My Promariner 50-Amp battery charger can be set to 25%, 50%, 75%, and 100% power settings. I leave it on 25% to keep my four 12V batteries topped up when sitting on shore power for extended periods. Out at anchor not running the genny, I might set it to 100% so that when I do run the genny, I get the house batts recharged a bit faster. This charger appears to be something you might need.

Steve91T said:

Ok I have five 6v batteries and two 12v batteries. All voltages are identical. All 6 volts are reading 5.7 and the 12’s read 11.8. This is with the charger off

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As mentioned, there's a 6th 6V battery hiding there somewhere, they have to be in pairs for most any modern system, I highly doubt you have a 6V system and 6V charger to support that 5th battery.

To check a battery properly, you have to charge it first for enough hours to completely charge it. Testing without charging won't really help you.

After charging let rest with no load for several hours, overnight is best. Now check voltage, should be 12.6-12.7 volts for brand new, a bit lower for older. Each 6V 6.4-6.3 volts. If lower, read individual cells with a hydrometer and you can determine if a single cel is bad or multiples. If all this passes, you can put a large load on the batteries (100 amps) and monitor voltage, should not drop below 11.5 volts but closer to 12V is better for a larger battery bank, it should recover quickly to 12.5+ after the load is removed.

If you can't charge the whole bank (your charger is overheating it seems like), you will need to separate the parallel batteries and charge/test each 12 V pair separately. You could have just one bad cell in one battery that is consuming most of the charge power and preventing the others from accepting a charge, or you could even have some corroded terminals causing issues. Three inexpensive automotive chargers can be employed temporarily on each 12V pair after you have separated them to accomplish this more quickly than having to do each one after another with your built in charger.

None of you batteries appear to be restrained. Image #1 shows the lone 6v wedged between 2 seacocks with no means of restraint in any direction. Essentially the seacocks are restraining that battery. As mentioned, neither battery boxes or covers on the positives.

You also have a bunch of directly connected, inline fused add-ons. Technically it's fine, but each of those items are hot wired with no means to isolate the device or circuit.

I might get banged up for this one, but .....'usually' in either series or parallel, the main positive is on one battery and the main ground is on the other battery. It kind of looks like you have Postive and negative on one bank, then have daisy chained them with the positive to the other set of batteries, and a common ground running through all of the them. The challenge is whether the interconnects can truly handle potential load.

Feel free to flame me on that one....I like to learn the hard way.

I really can’t tell how it is wired because some of the wires go out of sight and then, maybe, come up and make the connection. I think at this point it is just guessing. I don’t know how big the current draw is but all of the battery cables look small if there is any significant load on the bank. Also the connectors look poorly done, no heat shrink on them so there may be corrosion in the connections. On my battery bank all the cables are 4/0 because I don’t want any voltage drop. Large cables is an easy way to get the most voltage out of the battery bank. There could be a 6th 6 volt battery somewhere but if you are making a series bank you really want the interconnect wires as short as possible. Again I would get a certified marine electrician to spend a couple of hours doing an audit of the boats electrical system. Then there will be a plan on fixing the issues that everyone have noted, plus possible other problems that are not in the photos.

Shrew said:

I might get banged up for this one, but .....'usually' in either series or parallel, the main positive is on one battery and the main ground is on the other battery. It kind of looks like you have Postive and negative on one bank, then have daisy chained them with the positive to the other set of batteries, and a common ground running through all of the them. The challenge is whether the interconnects can truly handle potential load.

Feel free to flame me on that one....I like to learn the hard way.

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Shrew
I'm with you on balancing both loads and charging on batty banks. When I look at recommendations from many knowledgable "experts" they will show a good, better, best hook-up for balancing and strongly recommend balancing for optimal performance and batty life. Many arm chair critics will quote a small resistance difference and claim no difference. I don't know enough to argue the point but believe doing the best balancing is no more work than doing a half baked job and arguing it's good enough.

Thanks guys for the help.

Once my dad and I got a beer dinner and started thinking we realized that testing the batteries by touching the terminals was incorrect because they are all linked together. That’s why they are all identical.

Going to test cells when we get back and see what we see.

Good luck. We don’t mean to pile on with problems but on the forum there isn’t any way to know what your strengths and weaknesses are. I am pretty good at electrical and getting better at fiberglass but still know almost nothing about engine internal troubleshooting. That’s why we all try to help.

Just let us know what you discover re the odd 6V batty? You raised some eye brows and bet many are curious.
You would do yourself a favor by figuring out what each of those battys & wires supply.
It might be simplified a lot with a (or a couple) buss bar for the various connections and one or 2 main feeds.

Comodave said:

Good luck. We don’t mean to pile on with problems but on the forum there isn’t any way to know what your strengths and weaknesses are. I am pretty good at electrical and getting better at fiberglass but still know almost nothing about engine internal troubleshooting. That’s why we all try to help.

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Not at all. I appreciate the help. We’ve been super productive. Got the ac’s running better than they ever have, replaced the freshwater pump That died, sealed some windows that may have been leaking.

I actually understand electricity. I understand that I can’t see it and I understand that it hurts like hell when I touch it.

Steve91T said:

Not at all. I appreciate the help. We’ve been super productive. Got the ac’s running better than they ever have, replaced the freshwater pump That died, sealed some windows that may have been leaking.

I actually understand electricity. I understand that I can’t see it and I understand that it hurts like hell when I touch it.

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Hum try to touch your 6v batteries it won't hurt

The worst I ever got across was 300 volts. After I picked my eyeballs up off the bench and put them back in it wasn’t too bad...

The ProSport 20 is grossly undersized for that bank. ProMariner is awfully cryptic in their manuals on how big a bank they can charge but the bottom line is this.

On each output, yours appears to be a two bank model, the largest battery you can charge is a single G-31. This means a total bank capacity of about 200Ah is what the ProSport 20 is capable of charging without over-heating and eventually failing. These are small bank waterproof bass-boat chargers not large bank cruising boat chargers.

You're trying to charge a house bank of approx 450Ah and a start bank of about 200Ah. This is way too much for a ProSport 20.

You would be best to replace it with a "dry-mount" charger such as the 60A ProMariner ProNautic P or the Sterling ProCharge Ultra. It's same charger, same warranty, only the Sterling ProCharge Ultra is a lot less $$$ than the ProMariner..


As others have mentioned you'll need to figure out why you have that 5th GC2 6V battery and address that bank wiring.

Steve91
Maybe it is time to install a good marine inverter charger. If you shop right they are not expensive and if set up correctly will result in many benefits beyond high rate battery charging. Plus your genset run time will drop off dramatically.

This is what it looks like to me:

The upper picture shows a 6V GC2 battery. Where its leads go is a mystery. But nothing on a boat requires 6V itself other than to pair it with another GC2 battery to get 12V.

The lower picture shows 4 6V batteries, probably the same GC2 batteries as in the upper picture. They are wired series/parallel. To the left of those are two 8D batteries, probably for starting.

I wouldn't go so far as to say that they are all trashed. If the voltmeter reads 0.9 V low, then they might be fine. Check your voltmeter by reading the voltage on your car's battery after it has been sitting for a few hours. It should read 12.6-12.7.

I agree that the wiring is a mess, and have no idea what that lone GC2 battery is doing.

David