Cahrging my Batteries?? (Long + several pics)

Richard10002

Richard10002

Well-Known Member
Joined
17 Mar 2006
Messages
18,979
Location
Manchester
Visit site
Having established that having to run the engine for several hours each day to charge my batteries, (at anchor), seems excessive, I took a few pics of my system, and took some measurements..... can anyone make any comments as to what might be wrong, if anything:

3 battery banks: Engine (110Ah), Domestic (2 x 110Ah), Bowthruster/Inverter (200Ah)

I have a Sterling Power monitor, which provides volts and Ah for the domestic batteries, and just volts for the engine and inverter batteries, and I took the following measurements whilst the engine was running at 1500 revs:

Domestic: 13.16V at batteries, 13.2V at monitor
Engine: 13.43v at battery, 13.4v at monitor
Inverter: 12.93v at battery, 13.4v at monitor

The domestic battery bank showed 13.2A going in, and discharged by 36Ah

I then turned the engine off and got the following measurements, ( I think I had loads on all but the engine, but am not certain):

Domestic: 12.63 at batteries, 12.6 at monitor
Engine: 13.33 at battery, 13.4 at monitor
Inverter: 12.19 at battery, 12.2 at monitor

I think the thing that got me thinking was that i never get more than about 13.6v at the batteries, when it seems it should be 14v or more.

My father, (previous owner), tells me that someone doing some electric work on the boat had said that there was some kind of booster, but he doesnt always remember things correctly. The only thing I think it could be is the box of wires behind what I think is the solenoid.

The following are some pictures of the system - some of which i know what they are, and others i dont:

Engine and Domestic Batteries:

IMG_0702.jpg


Domestic Neg. post

IMG_0705.jpg


Domestic +ve post

IMG_0708.jpg


2 of the wires, (black and red), from the domestic batteries go directly to the electric loo, (via a 25A CB).

Engine Room - Battery switches for Dom & Eng. in white box. Dont know what the other things are?

IMG_0719.jpg


Alternator

IMG_0723.jpg


Solenoid???

IMG_0724.jpg


Wiring loom/box immediately behind the solenoid, (or whatever the previous pic is):

IMG_0726.jpg


Another view of the above wiring box:

IMG_0727.jpg


Any comments and advice welcomed, (even if it's only to tell me what certain bits are).

Many Thanks

Richard
 
Sorry cant comment on the setup BUT where the big red wire runs from the alternator it is close to the engine mount, this could rub through the insulation and cause a short and fire. I know because it happened to me.
 
Check the voltage at the big wire on the back of the alternator, with the engine running as previous test.
If the voltage is the same as battery, get local LSUK to check alternator and / or fit a new reg that is running at 14.4 volt.
If the alternator is at 14.4 volt, you have blocking diodes, and that's your volt drop.
It looks like you have a sensing wire from the reg to the large output cable, extend this to the service battery, and the alternator will compensate volt drop.

But check alternator volts first.

Brian
 
If he has these voltages on charge, what do you concider a fault ?


Domestic: 13.16V at batteries, 13.2V at monitor
Engine: 13.43v at battery, 13.4v at monitor
Inverter: 12.93v at battery, 13.4v at monitor

Brian
 
"What do I concider a fault?"
Er....not enough information! How did he take the readings other than those from the monitor? How old are the batteries? What state is the rest of the wiring in? (Some of it looks a tad manky). Has the alternator ever been serviced? If he's using a standard regulator (which he appears to be) he's never going to see 14.4V at the batteries anyway even if everything is working perfectly, is he?
Richard, have that proper chat with the charging expert at the Moody Association that you promised yourself. He'll sort you out.
 
it looks like a standard alternater, ,do you know its output,
as standard(no regulater booster fitted) and depending on its charging size i would not be surprised that it only charges to about 13.6, i would have expected 13.8 but that could be due to differences in voltage measurement.
13.8 is around what you will get from a standard alternater.to get the best from your batteries and system you really need to fit a regulater booster such as stirlings,this altrs the way the regulater works in the alternater. as halycon says check for current dropsetc as well. if you have a digital multimeter take all your readings with that .you then know that all your readings are correct to one instrument.
instead of running your engine for 2 hours split it into 2x1 hr preferablly with 3or4 hrs in between(obviously not possible when motoring,applies when at anchor) this will normally put more charge into your battery due to the sponge/absorbtion effect of a battery .
 
Re: Charging my Batteries?? (Long + several pics)

Richard.

Like one other here I suspect that that yellow wire on the back of the alternator s a sensing wire and so might be feeding duff info to the regulator so better it goes to the batteries under charge if this can easily be achieved.

On the back of the alternator there are 3 small terminals which have what looks like red...brown and grey wires...WHere do these go as they could be connected to an external regulator.

The voltages you show are much to low and you batteries will not be getting anywhere near a full charge. Aim for getting voltage at the battery of 14.4volts initially which drops no lower than 13.8 if the engine is running a long time.
 
Richard,

I think, to answer your question, you'd have to work through your system and draw a diagram of where the key battery wires go. Charging lines and feed lines - and where they're connected. Boring burrowing, but an investment . . .

The key points are:

Where does the alternator charging wire go? To the white box? Or to each battery bank via a three way diode?

Also, is the bow thruster distant compred to compared to the others?

As an alternative to diodes, the two little boxes alongside the white box may be voltage sensitive relays (sheer speculation this) designed to feed charge to the engine bank until that's charged, then divert charging current to the domestic bank.

Whatever, when your batteries are below 12.2 -12.3 volts (resting voltage) you need to charge at 14.4v at the battery. If you don't, it'll take ages to re-fill. And as a warning, when your batterys are well charged, any more than 13.6v (may occur after 12 hours motoring!) will cause some water loss from the cells and maybe some heating.

I suspect the big bundle of wires near your 'solenoid' is a Volvo engine wiring loom - nothing seriously to do with battery charging, but a Volvo owner can tie that one up.

I would guess here that your system is crying out for an intelligent charger (Adverc, Sterling) which senses battery voltage while charging and switches from 14.4 to 13.6 as appropriate. But how such a charger would be connected will depend whether or not you've already got a voltage sensitive relay at work.

Hope that helps a little bit . . .
 
The missing ingredient is a smart regulator. You need to get your batteries up to charge quicker and the only way to do that safely is a good smart regulator which will hold the charge constant at 14.2 volts or so right up to nearly fully charged.
 
[ QUOTE ]
Check the voltage at the big wire on the back of the alternator, with the engine running as previous test.
If the voltage is the same as battery, get local LSUK to check alternator and / or fit a new reg that is running at 14.4 volt.
If the alternator is at 14.4 volt, you have blocking diodes, and that's your volt drop.
It looks like you have a sensing wire from the reg to the large output cable, extend this to the service battery, and the alternator will compensate volt drop.

But check alternator volts first.

Brian

[/ QUOTE ]

Brian - this seems the easiest solution to apply/test, but I'll need a bit of help with how and what:

When measuring the voltage at the big red wire, (does this have a name or a letter - I'm reading/trying to get my head around The 12 Volt Doctors Alternator Book) - what do I connect the negative wire on the meter to... I'm guessing the engine block might do, but dont want to make a mistake.

Is that the regulator part of the alternator, where the yellow wire exits?. Do I leave it connected to the big red wire? And is it as simple as extending it, and connecting it to the positive post of one of the batteries, Which battery would be sensible choice?

If I'm not getting 14.4v at the alternator, I'm a bit knackered until I get to Malta, but that shouldnt be long now.

Thanks for the help so far

Richard
 
Thanks to all for the replies - I'll work through them, once I understand what all the wires are for etc.

I uses a digital multimeter to measure the voltages across the battery posts.

I'll clean the terminals.

I'll trace the wires when I get a chance - but it doesnt help that I dont know what they are, or what they do, yet - right at the start of the alternator learning curve.

The inverter battery is in the forecabin, the engine, (alternator), is under the center cockpit, and the engine/domestic batteries are under the aft cabin bunk.

Considering Sterling/Adverc/whatever, but want to get the basics sorted, and understand stuff, so I can make an informed decision.

It was a toss up between posting here first, or on MOA.... I chose here and, once I know whats going on, I'll get onto Grenville.

Thanks again
 
Ricard

The big red one will be B+ probably, but it's the one in your photo that the yellow goes to.
You should go back to the battery with the neg, But for what we need to prove the alternator body will normally do, you are looking for big errors, around 1 volt not 0.001 volt.
Yes the thing with the yellow wire is probably the regulator, and if you have blocking diodes will need extending to the service battery positive.
You have other problems to look at, but the low charge volts is the first thing to sort out, then do the others i.e. the bow / inverter battery, but do one bit at a time.

Brian
 
Hi Richard

I am not very techie. Before leaving the UK I had recommended Electrician (Tim on the Hamble) look over the wiring/charging set up onboard and explaining it to me in terms I understood. I was able to watch him as he explained/check the setup. He also showed me some basic fault finding. This was to my mind money well spent. Its sounds like this approach may help you. Nigel Calder book on electric boat fault finding was/is also a big help.

David
 
[ QUOTE ]
Richard
The big red one will be B+ probably, but it's the one in your photo that the yellow goes to.
You should go back to the battery with the neg, But for what we need to prove the alternator body will normally do, you are looking for big errors, around 1 volt not 0.001 volt.
Brian

[/ QUOTE ]

measuring from the big red wire to the alternator body gives 13.6v.... which I guess is the root of the problem from what you have said above.

preempting a little bit - you said i would need to get LSUK to look at the alternator, or get a regulator which gives 14.4v.

I'm anchored off Sicily, due in Siracusa tomorrow, or later this week, then Malta by early october, if not before. The regulator does not look like too big a deal - if i get one sent to me, or find one in Sicily or malta, is it something I can fit, bearing in mind i am not yet confident with soldering.

Over to you, and thanks again.

Richard
 
Richard

In the old day (1970 / 80's ) 13.6 volt was the stanadard alternator reg voltage for cars.
Most replacement regulators to-day are 14.4 volt, hense talk to LSUK.
The other option is to try a diode in the yellow wire, this will put a volt drop in the signal, and the output will be increased by .5 / .7 volt. It is possible that the regulator is dual sensing, but not probable.
Is there a electronic chap around who can make up a lead with a diode in that will plug the diode anode into the big red terminal, after removing the yellow. The yellow then plugs into the diode cathode.

Or if you like, I'll have a chat with my mate who runs the local LSUK depot.

Brian
 
You say you have a Sterling battery monitor but there are no pictures of the shunts or descriptions of their position. Since some equipment is connected direct to the battery the Ah reading is probably defeated.

Assuming the picture is the starter and the Domestic under the aft cabin The wiring is in my view terrible. Since the 2 on the right are the domestic (Due to link wire between reds) the one on the left is the starter. Therefore the poor starter current has to go via 2 unnecessary terminal junctions and then looks like heading off to a earth point sharing the domestic cable. How are the shunts fitted if the starter current goes through the same cable? Unless the shunts are in the positives or there is a hidden wire I can not see. I bet the lights dim when you start the engine?

When connecting up banks of 2 batteries to make the Domestic set: first link the two batteries with short wires and then connect the supply leads to the DIFFERENT batteries. This evens out the charge voltages and shows up faults in battery connections more easily. Each battery sees the same number of links in its circuit.

I am hoping that the picture is just too small to show the fuse bank for the domestic battery just out of shot. It should be within feet of the battery! I know a owner of a new yacht that burnt to the water line due to only 8 feet of unprotected cable.

The blue and silver boxes are relays of some sort. Since the output of one goes into the other and there are not enough wires to make sense I think they might not be used anymore. A closer picture might reveal more wires. They are probably only about 20A, at the most, so can not be taking any part of the transfer of power between batteries.

The alternator is a small, probably 50A, Valeo. Even with a booster this would not be adequate for the 400Ah of battery. (Assuming engine battery is for the engine). If you got it to produce the 50A, and had half used the batteries, that would be theoretically 4 hours but in practice probably nearer 6 hours to get to 90%.

Also using that Volvo for just 13A or even 50A is a bit cruel!

Adding a smart regulator would improve things but due to the distributed nature of the batteries and small cable sizes it would mean that you would overcharge one or other bank. Say it sensed the Domestic and you had been at anchor for 3 days, charging daily. The Windlass battery would be charged but the Domestic say in the morning would be 100Ah down. You would start the engine and most of the 50Ah would go to the Domestic bank. The voltage drop on the cables would be large at that rate. However the Windlass battery cables go the other way, so they do not see the current, and have little voltage drop. So the Windlass battery sees the higher Alternator voltage and is overcharged and gasses for 2 hours.

Altering of the charge by using diode drops on the alternator is a certain way to destroy your batteries. For the same reason as above and say you have an emergency and motor at high revs for a day or so. The battery voltages will come up eventually then boil the batteries.

If you want to use your engine to charge batteries, otherwise you would not be complaining about the time, then I suggest you fit ANOTHER alternator. Leave the Valeo on the Starter battery and as a emergency spare. Fit another one off a second pulley for the Domestic. Charge the Windlass off a 12v to 13.8v trickle charger or a stepped battery to battery charger.

See example I found on web:
http://www.reginasailing.com/General/Boat/Equipment/HOA.html

I strongly suggest a full survey of the high power battery connections and charging by a experienced boat engineer.
 
[ QUOTE ]
Richard

The other option is to try a diode in the yellow wire, this will put a volt drop in the signal, and the output will be increased by .5 / .7 volt. It is possible that the regulator is dual sensing, but not probable.
Is there a electronic chap around who can make up a lead with a diode in that will plug the diode anode into the big red terminal, after removing the yellow. The yellow then plugs into the diode cathode.

Or if you like, I'll have a chat with my mate who runs the local LSUK depot.

Brian

[/ QUOTE ]

Brian,

where I am, I dont know anybody, and dont speak the lingo, (I can do a bit of shopping, order beer and ice cream), so dont think I'd have much success with a diode lead

/forums/images/graemlins/laugh.gif

As for asking your mate, I guess you'll need some info. I'm rolling around a bit at the moment but, when I get to Siracusa, I'll see if there is any identification on the alternator. I know the engine is a Montego 2 litre diesel, and the alternator is a Valeo.

I suspect this is something I'll have to deal with in Malta, but I'm glad we've identified the issue.

Thanks for the help

Richard
 
Richard,
I fitted a Sterling regulator and the NASA battery monitor. So can get the same readings as you. We also have similar batteries except my bowthruster battery is connected as the second domestic battery (288 Amp Hours together). When anchored for a night this week (lights, fridge and anchor light) the domestic battery voltage dropped to 12.5V (monitor showed 70% capacity remaining) from a normal 12.7V (no charging and left for some time with a small load - Navtex). When I started the engine the next morning there was 50 Amps going into the battery at 14.8V and half an hour later it was down to 8 Amps at 13.8. I think the figures you want to look at are the voltage before you start the engine and the initial current and voltage a couple of minutes after starting. You can then compare the output of the alternator with its norminal max charge rate. I agree with the other threads that probably you need to sense from the battery and need a smart regulator. They are very easy to fit - there was an article in Sailing Today on fitting one last year.
 
I will see mate next day or so, have printed your picture, will try to identify at this end.

Can you follow your wiring when you are stable, i.e. how does the alternator split the charge to domestic and bow battery, that will be the next stage.

Brian
 
You must log in or register to reply here.

Share this page

Top