Argh............ Batteries not Charging

[oldgit]

Pre to getting somebody in who actually knows what they are doing.

Both Leisure and Engine Start batteries being charged from Sterling Shore Power unit and Generator, but when underway, alternators only appear to be charging the engine batteries not the leisure.
Multimeter assures that alternators both are putting out loads of volts .
Presume there is lurking somewhere in the engine bay a box hiding "a something" that should be charging both/either Engine or Leisure depending on which set need charging.
Assuming the problem is after the three master switches for engine/house batteries and emergency.

What am one looking for and where , there are a couple of substantial mysterious water proof boxes in there with hefty cables entering but no markings on the outside.
Surely not as simple as fuse in the leisure battery charging line.
Comments welcome.

 

[justanothersailboat]

Doesn't a three-switch arrangement (engine, house, emergency combine) normally go with a VSR to charge both batteries at once when the alternator is running? Perhaps you have a failed VSR? "a couple" of substantial unlabelled boxes sounds like more mystery than I could get comfortable with.
At least the fuses are the easiest thing to test... though a charging fuse is usually hefty enough that if it's gone, I'd want to check a lot more before just putting it back.

 

[lustyd]

Normally, yes, but a VSR does the same as the emergency connect switch so someone might have gone the cheap route and left a VSR out.

 

[Sticky Fingers]

Pre to getting somebody in who actually knows what they are doing.

Both Leisure and Engine Start batteries being charged from Sterling Shore Power unit and Generator, but when underway, alternators only appear to be charging the engine batteries not the leisure.
Multimeter assures that alternators both are putting out loads of volts .
Presume there is lurking somewhere in the engine bay a box hiding "a something" that should be charging both/either Engine or Leisure depending on which set need charging.
Assuming the problem is after the three master switches for engine/house batteries and emergency.

What am one looking for and where , there are a couple of substantial mysterious water proof boxes in there with hefty cables entering but no markings on the outside.
Surely not as simple as fuse in the leisure battery charging line.
Comments welcome.

Did this previously work, so now it’s faulty? Or has it never worked?

If the latter, it might simply be arranged like that. Our summer charter boat needed shore power to charge the leisure batteries. And forum member PEJ has a very lovely big motor yacht that also requires shore power or generator to charge the leisure batteries.

So would be worth checking the manual if you have one, to see what the manufacturer intended.

 

[Sandy]

What does your voltmeter tell you? Is the voltage the same at the alternator end and the battery end? If not you will need to test each section of wiring until you find the same voltage as the alternator.

Work through it logically and slowly.

 

[pmagowan]

Pre to getting somebody in who actually knows what they are doing.

Both Leisure and Engine Start batteries being charged from Sterling Shore Power unit and Generator, but when underway, alternators only appear to be charging the engine batteries not the leisure.
Multimeter assures that alternators both are putting out loads of volts .
Presume there is lurking somewhere in the engine bay a box hiding "a something" that should be charging both/either Engine or Leisure depending on which set need charging.
Assuming the problem is after the three master switches for engine/house batteries and emergency.

What am one looking for and where , there are a couple of substantial mysterious water proof boxes in there with hefty cables entering but no markings on the outside.
Surely not as simple as fuse in the leisure battery charging line.
Comments welcome.

You are looking for a schematic diagram of your system. If you can't find it you need to make one by careful examination of your system. Then you can problem solve if things are not working as they are supposed to rather than as you would like.

 

[oldgit]

Pretty certain was working OK previously
On boat and have checked volts on batteries.
13.21 on all batteries both engine and leisure.
Run engines with emergency switch off.
Engine battery 14.2
Leisure remains at 13.21.
Run engines with emergency switch ON volts on engine batteries go up to 14 .2 and so do leisure batteries.
????????

 

[ylop]

Pretty certain was working OK previously
On boat and have checked volts on batteries.
13.21 on all batteries both engine and leisure.
Run engines with emergency switch off.
Engine battery 14.2
Leisure remains at 13.21.
Run engines with emergency switch ON volts on engine batteries go up to 14 .2 and so do leisure batteries.
????????

Normal lead acid batteries? then 13.2 is not the "resting" voltage so something has been charging it.
Every boat's wiring is different. Even with common production models unless its brand new someone may well have added/removed/bypassed features so you need to find or create yourself a picture of the wiring. For this is should be fairly straightforward as the wiring will be big chunky cables so quite obvious compared to the typical spaghetti devices are connected to. Pictures of your annonymous boxes might help as others may recognise the shape/design.

There's 3 common ways of linking engine / starter batteries: a big switch you turn manually, a big diode which charges both but stops current flowing from starter to house, a VSR which "detects" when the engine battery side is high enough volts and links them automatically.

 

[Alex_Blackwood]

Pretty certain was working OK previously
On boat and have checked volts on batteries.
13.21 on all batteries both engine and leisure.
Run engines with emergency switch off.
Engine battery 14.2
Leisure remains at 13.21.
Run engines with emergency switch ON volts on engine batteries go up to 14 .2 and so do leisure batteries.
????????

If the system was working previously it would indicate that either you ran (1) with the emergency switched closed, (2) you have a VSR which has gone Defective.
How "Pretty certain" are you? I think that as the man on spot you will have to do some circuit tracing and verification. Sorry can't be more helpful but on line diagnoses is pretty difficult, despite what the Doctor says!

 

[oldgit]

Normal lead acid batteries? then 13.2 is not the "resting" voltage so something has been charging it.

Both engine and leisure batteries will charge fully via 240V Sterling shore power and my onboard diesel generator, only the alternators appear to charge engine batteries but not leisure batteries.

 

[Tranona]

Both engine and leisure batteries will charge fully via 240V Sterling shore power and my onboard diesel generator, only the alternators appear to charge engine batteries but not leisure batteries.

The wiring from the mains charger and generator are normally independent from the alternator charging circuit.

 

[srm]

I had a similar problem years ago. After motoring the full length of the Caledonian canal the house batteries had not charged properly. A day at anchor, a multimeter, and a long length of heavy duty cable finally located the cause - a resistance fault in the negative return from house batts to engine block (any previous owner's wiring is usually a mystery). Running a new negative return gave a much better charge rate than I had seen previously.

 

[Sianna]

I had a similar problem, the alternator output was showing around 14v but no charge showing on the leisure battery.

It turned out to be the terminal on the back of the alternator, (underneath the plastic cover) which was slightly corroded, the end of the alternator terminal was showing 14v output, it was just not getting back to the battery, a clean up with a wire brush was all that was needed to recover the charging of my leisure battery.

Probably not the same problem but always worth a quick check?

 

[oldgit]

Cannot find anything resembling any device to split the charge from the alternators, it might be lurking in the hull somewhere but after previously failing to discover where ACM had hidden a auto antenna switching box, admitted defeat and simply fitted a 3rd antenna for the AIS signal.

In order to not to compound the problem have invited somebody who actually knows what they are doing to take look and sort the mystery.
Supplied detailed and comprehensive instruction manuals are all in French.

Find it difficult to believe that while underway you need to have the emergency switch "ON" to charge both sets of batteries, then need to turn it off on arrival to prevent the fridges flattening the start batteries .
Yes this did happen, the genny of course was impossible to start.

Fortunately the bowthruster battery was removed, taken back aft and with a set of jump cables got the genny started .

 

[Sandy]

Cannot find anything resembling any device to split the charge from the alternators, it might be lurking in the hull somewhere but after previously failing to discover where ACM had hidden a auto antenna switching box, admitted defeat and simply fitted a 3rd antenna for the AIS signal.

Did you follow the cable(s) from the alternator all the way to the batteries?

I always worry when people use words like 'might' as it indicates that they have not done the task they set out to do.

Find it difficult to believe that while underway you need to have the emergency switch "ON" to charge both sets of batteries, then need to turn it off on arrival to prevent the fridges flattening the start batteries .

This is quite normal. The reason for having the 'emergency' part of the switch is to that you can charge both banks at once.

Sounds like your problem is somewhere between that switch and your house battery bank.

 

[lustyd]

Find it difficult to believe that while underway you need to have the emergency switch "ON" to charge both sets of batteries, then need to turn it off on arrival to prevent the fridges flattening the start batteries .

It's not always an "emergency" switch, sometimes it just combines the banks for convenience. They're referred to as emergency simply because they are the emergency engine start procedure, but when the switch is closed it means everything is charging.

Since you've said it used to work though, that's unlikely to be the solution here. You must have either a split charge relay or a VSR somewhere. Easiest route would be to trace cables from the battery end on the positive side. From the house battery you'll have one positive for the house loads (switch panel, usually) which goes to the house switch. You'll also have a cable for each charge source either direct to the battery, on the battery side of the switch, or on the load side of the switch depending on the religion of the installer with regard to isolation switches. There may be bus bars where the cables branch off, but these won't change anything. I'd be surprised if you have more than 4 or 5 cables from the house bank either directly or indirectly.

 

[pmagowan]

Schematic! Either you are drawing one or you are paying someone a lot to draw one for you.

 

[lustyd]

I know this is PBO, but there's nothing actually wrong with paying professionals with skills you don't have to do jobs you can't do.

 

[pmagowan]

I know this is PBO, but there's nothing actually wrong with paying professionals with skills you don't have to do jobs you can't do.

Nothing wrong with it other than the cost. Certainly everyone should be able to draw a schematic. At the very least it saves you an hour of your professionals time and your money. You don't need correct notation or expert skill to draw a picture of a battery and a coloured wire coming from it then trace this to the next dohickey etc. The problem is probably obvious on the schematic and if posted on here then no professional fees likely needed. If you can't use crayons then definitely call the professional in.

P.S. Should you really be the skipper of a boat if you don't even have a basic understanding of your boats essential electrical systems? Unless of course you have an engineer/electrician on crew. Genuine question, no implied answer.

 

[Alex_Blackwood]

Nothing wrong with it other than the cost. Certainly everyone should be able to draw a schematic. At the very least it saves you an hour of your professionals time and your money. You don't need correct notation or expert skill to draw a picture of a battery and a coloured wire coming from it then trace this to the next dohickey etc. The problem is probably obvious on the schematic and if posted on here then no professional fees likely needed. If you can't use crayons then definitely call the professional in.

P.S. Should you really be the skipper of a boat if you don't even have a basic understanding of your boats essential electrical systems? Unless of course you have an engineer/electrician on crew. Genuine question, no implied answer.

You only have to look at some of the questions, and answers, in this forum to to get an inkling into that. Not just electrics but mechanical as well.