Electrical Issues

[Swiss sailor]

Hi
I've just bought a Hunter 410 sailboat. It has some issues with the battery charger and the alternator.

The actual setup:
The boat has a 1999 Yanmar 4JH2E diesel engine with a 60A alternator. In addition there is a NL 6KWh generator on board. The 12V house bank (approx. 6 years old) consists of 2 x 2 golf cart batteries (6V) and there is one group 27 12V starter battery (approx. 2 years old). I have two battery switches, one for the house bank and one for the starter battery (all original from Guest). The battery charger is a Guest 30A, original from 1999 as well. Since I can spend a couple weeks on the boat only (the boat is across the Atlantic from where I live), it sits on the dry for most of the time, shore power hooked up. In approx. 1 year we plan to go on a cruise to the Bahamas / Exumas.

The problems:

The Alternator
With the engine running, we could not measure any noticeable voltage output from the alternator. After 6 hours motoring on the ICW, the engine did not start anymore, when trying to leave the dock due to low battery capacity. A jump start device did the job.

The battery charger
With the shore power on, I could not measure any charging voltage at the house nor at the starting battery.

The house battery bank
I'm considering to replace the 4 batteries because of their age.

The planned approach
First- I'd like to replace the alternator with an API 20107 ALTERNATOR, 60-AMP which I found here:
Yanmar 129772-77200 Replacement Alternator - Brand New : Yanmar
Very reasonable price, but does anybody have experiences with this product?

Second- I will replace the battery charger with a Mastervolt 35A or a ProMariner ProNautic 1230P 30A. Which one would suit better to the given setup? Which one is of better quality / easier to install? Any thoughts?

Third- I'll replace all the batteries. What would be the right choice? I thought I would replace the batteries with the same types as are installed now. Any thoughts on this, considering I'm not able to maintain the batteries for most of the time)?

And here comes the strange thing
All the 3 (two from the rear and one from midship) ground cables, attached to the keel bolts are corroded away (see picture)!!! Could this be the reason why the battery charger refuses to work? Anybody saw this before? The bilge was covered with salt water, which I have cleaned out now and sealed the source where it came from.

Any comment / thought or hint would be appreciated!!

[Boracay]

I'd replace the faulty cables before anything else.

Then I'd check the voltage and specific gravity of the batteries. If they are totally dead then I'd replace the 6 house batteries. It may also be worth considering replacing the 2 year old starting battery unless you have lots of time to fiddle round with things.

Next I'd get a couple of small solar panels with matched controllers and connect them so the batteries are being charged full time. My opinion is that the trickle charge that comes from solar panels is the best way to keep batteries in good condition. if you're going cruising then the largest possible solar array is desirable.

Unless money is really tight I'd go with the biggest possible battery charger. I have a 55 amp one and it's barely adequate.

It may not do any harm to replace the alternator but if there is no battery voltage to excite it then the alternator will most likely not work.

[DeepFrz]

Check out what Maine Sail has to say about battery chargers here: Installing A Marine Battery Charger Photo Gallery by Compass Marine at pbase.com

If your batteries are not completely shot, which I think they probably are, they don't have much life left in them. Replace the house bank. Its difficult to say if the start battery is shot or not from the info you have given. Sounds like the alternator is also shot.

[keithwins]

Seems like a short or an open circuit, could be either or both from your description. The "measure no voltage" sounds more like a short. Not completely certain how electrically experienced you are.

I'd disconnect everything and measure things one at a time. If possible, throw the batteries one at a time on a trickle-charger, for a day or two, and see if they hold a charge. Checking with a hydrometer is a good idea: that's particularly helpful when they are all still connected. I would take the opportunity to clean all contacts, make them shiny and new and tight (after you've checked everything). Check the output of your alternator without any load, same with the charger. Some people keep a dilute water/baking soda mixture to clean the tops of batteries that can have a mist of battery acid on them from the hydrogen bubbles generated especially during periodic over-charging (equalization: look it up) -- if you've got a bad charge controller, it could be over-charging regularly, exacerbating this problem: I'd expect corrosion to be corrolated with distance from batteries, if that's the case and if there's enough difference/distance to tell. Lubricating all joints with petroleum jelly as you reconnect may slow down corrosion. I've heard of people applying liquid electric tape over battery terminals to avoid corrosion, sounds like a good idea but I don't really know in a marine environment (keeping things dry might translate into keeping them wet when things go wrong). Make sure batteries are properly topped off with distilled water.

I am a fan of figuring out what's going wrong before fixing things. Seems to work better in the long run.

Note that a bad battery (or even one bad cell) will gradually degrade an entire bank due to the inability of the charge controller to properly charge everything.

Make sure there's not a short somewhere else on the boat, possibly associated with a circuit that's not always on: that could lead to intermittent problems that quickly kill new equipment.

Good luck.

[Stu Jackson]

Ground cables to the keel shouldn't be part of the electrical circuit, it's for bonding not circuit grounding.

The West Advisor: Marine Grounding Systems

[smac999]

if you do end up changing the charger get something much bigger. with 4 golf carts and a 6k genny I'd be in the 70-100a range. otherwise you are just wasting time and fuel running your genny to charge them back up so slowly.

I would consider an inverter / charger if you don't already have one.

but I would spend more time to figure out what is really happening.

[pbiJim]

For some reason, the negative wires on a salt water boat always seem to rot out faster than the positives. A chemist could probably tell you why, but I'm no chemist.

I would start by replacing all the bad wires, then see what works & what doesn't. If the bad wire was the reason that the alternator quit, then the alternator probably has a blown regulator on it. Most regulators don't like open circuits. You may be able to replace the regulator for less than the cost of the alternator. I don't know that particular alternator, so I am just talking in general terms here. The specs on that regulator say that it has an internal regulator, so replacing the alternator should get rid of the problem, even if it is a blown regulator.

Battery manufacturers will usually publish charts that show the proper charging amps for a given size & type of battery. Just off the top of my head, I think that flooded cell batteries take heavier current than AGM & AGM usually take heavier current than gel cells, but don't quote me on that, look up the battery manufacturer's recommendations. Also just off the top of my head, I seem to remember charging an 1150ah flooded cell battery with a 100 amp charger. That should give you a rough idea of a normal charging relationship, but again, see what the battery manufacturer recommends for a particular battery.

[Amnesia II]

pbiJim is on the right track regarding matching alt to housebank size. I have a bank of 850 a/hr and charge that with an Electromaax 200amp alternator kit with a balmar external reg. So the matching is nearer an optium of 25%....it seems to work well!
Cable sizing is very important on the charging circuit...big is better!

I concurr with Deepfiz.....Mainsail is the man!

[keithwins]

Oops, right, don't operate the alternator open. Sorry, I'm trying to translate off-grid house solar battery bank thinking to marine, without too much experience at marine. Sorry for any misinformation.

[keithwins]

On big expensive solar battery banks (for houses), there's a lot of attention to charging rates, etc. And periodically (anywhere from a few times a year, to a every month, depending on the batteries & the person/use), they get equalized, to try to drive sulfation off the plates and make the cells behave more uniformly. I don't know if people do this in a marine environment, most of your battery banks are much smaller. This is only for flooded batteries.

[noelex 77]

Originally Posted by Stu Jackson

Ground cables to the keel shouldn't be part of the electrical circuit, it's for bonding not circuit grounding.

+1. This is a separate problem to your electrical problems.

The fact that both the alternator and battery charger are not working suggests it may be a simple poor connection somewhere. I would certainly look at this before forking out money on a new battery charger and alternator.

If the alternator is faulty these are usually easily fixed by an automotive electrician. The most common problems are blown diodes, which are cheap to fix. I would at least do this as spare.

The Yamahar alternators are cheap on ebay because they are difficult (not impossible) to convert to external regulation so many people buy a different brand alternator and sell the Yanmar (Hitachi) one
If you are planning living away from shore power and the alternator is your only source of power then external regulation is likely to be beneficial, or even essential, but it depends on how your charging system is set up.

Solar power is worth considering.

[Swiss sailor]

Thank you all for the comments!
To be honest, electrical systems are not my strongest discipline... but I'm trying to improve it

But the link to the explanation of the bonding system was helpful. Certainly I will reconnect this cables. But they do not seem to be part of the charging problem, since they do not belong to the electrical circuit as I have just learnt. The more I'm looking the cbles and considering the fact that all 3 cables are "corroded" away - could this come from a lightning strike? But would such a strike not kill all electronics on board (they are all in proper working condition).

And yes, I followed the installation documentation of the Sterling battery charger very carefully. What a nice instruction!

Many of you voting to install the biggest charger, suitable for the setup.
I read in other threads that this could cause other problems. As I'm away for longer periods and nobody can look after the water in the batteries, would a much stronger charger, say 80 or 100A not lead in to overcharging / cooking up the batteries over time? The boat is hooked up on 110VAC / 30A shore power all the time while on the dry. So sufficient power for the charger.

The boat is located in Florida. This is the reason why I did not consider solar panels on the boat yet. If a hurricane or a though tropical storm comes across, I would need to remove the panels for safety reasons. But this would be a difficult task when being 6'000 miles away. Originally The boat ha a small panel above the companionway, but they were of very poor quality and I have not found a replacement for this one yet.

For the time being on the boat, the generator would help me out to top up the batteries whenever required. If I finally go on the cruise, solar panels would be definitely something I would add on.

[noelex 77]

No a larger charger will not cause any problems. It will regulate to same voltages and water loss will be the same.

Using the generator a larger charger would be helpful, but on shore power it will make little, or no difference.

[sailorboy1]

there are a few different wiring and charging setups on the 410

Do you have an inverter? If you do you need to have the inverter selector switch on to charge the house batteries.

[Swiss sailor]

Actually I did't find an inverter aboard. This is maybe due to the fact that the generator has been factory installed. Although there are additional red cables running to the charger compartment, the battery switches are not the ones, Hunter has built in when a inverter is installed.