I think I have an electrical problem :(

Sea Change

Sea Change

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Can anybody work out what might be up with my boat at the moment?
Gave the engine a good run the other day, charging both batteries, first time in a few weeks that I'd run it. Then went back to the boat a couple of days later and noticed the cabin lights were pretty dim. Strange, as the batts should have been full. First battery failed to start the engine- turned over and clicked but didn't fire up. Switched to second battery which sounded healthier but still didn't get it going. First battery is easier to remove so I took it home, and couldn't get it above 12v on the charger. I think it might be toast. Anyway, back to the boat to try battery two again. Took a voltmeter with me and watched the voltage drop to about 3v when I tried to start the engine. Not much good!
Disconnected as many circuits as I could, cleaned up contacts in battery box and isolator, and tried again. Engine damn near started. Decided to change out the fuel and air filters in case these were not helping (they were in need of change anyway).
Went to try the engine, and this time, absolutely nothing. Not a sausage. I'm really confused now.

The engine (a Beta) has a basic control panel, with a green power light, some red warning lights, and a buzzer. At the moment when I turn the key to 'heat' the green light comes on but nothing else happens. There's a slight voltage dip so I wonder if the glowplugs are working OK. No buzzer or red lights. When I turn the key to start the engine, just the green light again- the engine doesn't even try to turn over.

Anybody have any suggestions where I can start looking? I think it must be a short or a failed contact somewhere.
 
I’d start like you did by disconnecting as much equipment as possible. Then pull off the negative battery connection and use your meter to determine if any current is flowing from the terminal to the battery connector. If everything is switched off then no current should flow; if you measure a current it indicates a problem. Next try reconnecting everything, one at a time and checking to see if that causes a current.
Once you’ve done that and found what is drawing the current you can investigate the cause.
Batteries don’t like to be discharged too much so get them charging and they may be serviceable if not left for long.
 
Have you an automatic bilge pump which might be eating batteries? I discovered the hard way that a 15 second run every ten minutes can have quite a cumulative effect over two months ...
 
I don't think I have a phantom battery flattening device- the battery was giving me 12.5+ and anyway it cannot take much oomph to sound the little buzzer on the control panel. More inclined to think that there is a dodgy connection somewhere, question is, where to start looking...
 
Not a good time to change fuel filter when turning engine over via batteries is a problem, but trust you have bled the system through enough for when you do get your electrical problem sorted. Back to the electrics, you say it started OK a few days earlier after a gap of a few weeks, had you charged the batteries prior to this heathy run? Presume you have a basic 1, 2, both battery selector? Lots of basic checks and observations possible, but it helps if you also have, or can borrow, a clip on ammeter. Most important too when quoting measured voltages, is having confidence in the voltmeter, and perhaps as a test, try in on your car and see what it indicates both prior to starting, and when running/charging. Then you need to charge up your batteries (at home if necessary), measure their open circuit charged voltage (at least 12.5v) and connect them back on boat. If no ammeter, put your voltmeter across battery terminals before connecting and confirm still OK, then connect (with no known load, ie, all circuits turned off, including the battery selector switch, and see if battery voltage still OK. Then select battery and repeat checks, then switch ign to heat and monitor voltage again whilst heat on (may drop a volt or too as heaters warm, and also listen for heat relay clicking in). Then, if OK so far, try cranking, and if not turning over, see what's happening to the battery voltage as you try to crank. If it is dropping substantially, then start solenoid likely to have operated OK, and batteries, and/or poor connections in starter circuit (including battery terminals) may be at fault. Without you having an ammeter, that's the best I can suggest for now, but it may at least give some more clues.
 
I have a multimeter but didn't think to measure current with it, just used it for voltage. I'll give the battery a charge overnight and see how I get on, it's been reading about 12.6 which I thought was fine, but maybe not.
 
What do you mean by 'gave the engine a good run'? How long exactly? What's the charging system? Is it a standard alternator etc or have you got a Stirling alternator regulator or similar?

I had a friend who used to say that his batteries must be charged as he'd motored down the river the harbour (maybe 40 minutes of motoring?) The answer was that his batteries were barely registering a charge at all buy the time he stopped engines.

What sort of time are we looking at for your, 'charge the batteries etc?'
 
My post crossed with your last one, but still applies. IF it is a bad connection problem, then volt drop across bad connect likely to warm it up, so feel battery terminals, start solenoid, battery isolator switch, and any other joints in the start circuit for heat.
 
Thanks for all the tips.
I had he engine running in idle astern for about an hour. I also had some lights etc on at the time so perhaps I'm being a bit optimistic about how much charge went into the batts.
Still, a 12.5v batt should be lighting up the engine control panel, and at least attempting to turn the engine over.
The cabin lights work fine off the battery, by the way.
 
Re engine charging batteries, one or two alternators, and how connected? Even with a dedicated 70 amp alternator, back emf from a healthy battery will limit charging current considerably, and may only feed a few amps to battery after a short while, and hence will take a very long time to charge a near flat battery, say at least 12 hours of engine running at a guess.
Re your multimeter on amps, take care as likely to be only a low range, perhaps up to 10 amps, and any more likely to blow meter internal fuse.
 
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john_morris_uk said:
A one off battery voltage doesn't give a huge amount of information about the true state and charge of a lead acid battery. I'm not convinced one hour of charging in 'tick over' astern will guarantee a charged battery.
Click to expand...
It will probably put back about 25%, if that. My mate used to run the shore power charger for about an hour, then turn it off. He was shocked when I explained that it probably needed about 20 hours.
 
Battery problem

Sea Change said:
Can anybody work out what might be up with my boat at the moment?
Gave the engine a good run the other day, charging both batteries, first time in a few weeks that I'd run it. Then went back to the boat a couple of days later and noticed the cabin lights were pretty dim. Strange, as the batts should have been full. First battery failed to start the engine- turned over and clicked but didn't fire up. Switched to second battery which sounded healthier but still didn't get it going. First battery is easier to remove so I took it home, and couldn't get it above 12v on the charger. I think it might be toast. Anyway, back to the boat to try battery two again. Took a voltmeter with me and watched the voltage drop to about 3v when I tried to start the engine. Not much good!
Disconnected as many circuits as I could, cleaned up contacts in battery box and isolator, and tried again. Engine damn near started. Decided to change out the fuel and air filters in case these were not helping (they were in need of change anyway).
Went to try the engine, and this time, absolutely nothing. Not a sausage. I'm really confused now.

The engine (a Beta) has a basic control panel, with a green power light, some red warning lights, and a buzzer. At the moment when I turn the key to 'heat' the green light comes on but nothing else happens. There's a slight voltage dip so I wonder if the glowplugs are working OK. No buzzer or red lights. When I turn the key to start the engine, just the green light again- the engine doesn't even try to turn over.

Anybody have any suggestions where I can start looking? I think it must be a short or a failed contact somewhere.
Click to expand...

I know this sounds obvious but are your batteries any good? Take them off and charge them overnight , then take them to Halfords or a car accessory shop and get them tested with a discharge tester. Failing that you could charge up your battery and then try it on your car. You could also try your car battery on your boat. If there is a big difference, and there probably will be, your batteries are knackered and you need new ones.
 
nigelmercier said:
It will probably put back about 25%, if that. My mate used to run the shore power charger for about an hour, then turn it off. He was shocked when I explained that it probably needed about 20 hours.
Click to expand...

I agree. I was too tired to go into a fuller explanation last night and I was falling asleep at the keyboard…

If the batteries are not in their first flush of youth, and the charging regime has not been very rigourous. (And with respect to the OP, claiming that they have had a 'good charge' from one hour of running at tick over is a bit of a giveaway that the charging might not have always been very good) the batteries will have deteriorated and have a reduced capacity. They might be on their last legs without him realising. In addition, if the batteries have been left discharged for any length of time, that in itself destroys the battery. (Who loves lead acid batteries?)

The fact that they started the engine a month ago is no guide whatsoever. Engine start only takes a very tiny amount of charge out of a battery so long as you are not cranking the engine over for minutes. (You'd burn the starter out if you did that, and fill the exhaust with cooling water which would potentially get back into the engine but we needn't go into those pitfalls here…) If the engine is ready to go and in good condition an 'almost flat' battery will still start it and you might not notice any problem at all.

In addition, resting the batteries when they are nearly flat will allow a little charge to equalise out on the plates and come to the surface. The fact that the batteries 'recovered' a little is entirely predictable.

Here's my best guess at the situation.

The batteries are well on their way out. They might be ok but I strongly suspect that they are cream crackered. The OP starts the engine and the alternator (which doesn't have a smart charge system) doesn't really put any charge back into the batteries. The engine isn't running fast enough and the alternator doesn't push much charge in. The batteries continue to self discharge for the next month. Some debris might have fallen between the plates - who knows? He comes back and discovers he's got flat batteries. Changing the fuel filters does nothing to help start the engine and is actually counter productive.

I think the glow plugs are working; hence the voltage dip on switching to 'heat'.

IMHO here's a suggested solution. Take the batteries off the boat and charge them SERIOUSLY for a few days on a decent battery charger. Check the voltages when they have rested. Monitor them and ideally do a capacity test (discharge them into a known load like a high power car headlamp bulb and monitor the voltage over the next 24 hours etc.) Recharge them properly and fit them to the boat. Obviously if the boat has 230 volts power available you don't have to take the batteries off the boat to do all this. But you do have to be there to monitor the batteries when they are being tested for capacity.

I would also strongly suggest the OP fits some sort of battery monitor system so that he/she can see what is happening to the batteries and how they are being charged and what state of charge they have in them at any one time. There are several available and the more sophisticated ones 'learn' the characteristics of the batteries and give you a very good idea of what is happening. I would even more strongly suggest that he/she fits a smart alternator regulator to the alternator. It will improve the charging regime of the alternator dramatically.
 
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Sounds like the batteries are shot. How old are they? We fitted top of the range batteries to our Iveco truck 3 years ago. Tbe truck, like a boat, doesn't get used very often and now won't hold tbeir charge. So its off to the trade counter to get a cheap pair this time and we will see how long they last.
 
philwebb said:
I know this sounds obvious but are your batteries any good? Take them off and charge them overnight , then take them to Halfords or a car accessory shop and get them tested with a discharge tester. Failing that you could charge up your battery and then try it on your car. You could also try your car battery on your boat. If there is a big difference, and there probably will be, your batteries are knackered and you need new ones.
Click to expand...

+1 mostly.

The obvious is that the batteries are shot, not charged, not charging. Buy a new one, or borrow one from somewhere, and see if the engine starts - if it does, you know the engine is fine. It could then be that the batteries are knackered, or not charging.

1 hour idling for a flat battery will do nothing!
 
Does it make any difference if I point out that it was not a month between the last engine run and the start of the problem, but rather a day or two?
Also that I have the batts wired so that battery two never does anything except receive a charge. I always start on batt 1, use it for lights etc, and only once the engine is running will I bring batt 2 online. That way it should always be fresh and ready to start the engine.

The other day, batt 1 started the engine, as normal, despite sitting for weeks. I then brought batt 2 online as well.
Two days later neither of them would start the engine. Batt 1 seems truly b*ggered as it won't even light the cabin lights anymore.

What has me really perplexed is that the engine was turning over like a goodun whilst giving me about 12.6v, and on the next try, a couple of hours later (after changing the filters) it would do nothing at all. Well, it would happily power the cabin lights, including the voltage sensitive LEDs, but I've never before had the lights on the engine control panel fail to come on, or the buzzer fail to sound.

I have the surviving batt on charge just now, but I don't hold out a lot of hope. It seems a more complex problem than that.
 
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