Charging Problem for the hard of understanding.

[oldgit]

Thanks Paul.
Off down the boat again this morning, the wife is convinced there is another "she" in my life, which is true in a way.
This time going make sure it is only the alternators putting volts into the system.

The problem is simply that on any decent run ( 7-8 hours from the Mudway to Teddington )the leisure batteries do not appear to be getting charged from the alternators.
As for charging the domestics during a couple of hours a day on tickover while on the Thames, no chance .

 

[Alex_Blackwood]

Because the upper brown wire goes to the Stb alternator, there is no connection to the port alternator. For the port alternator to charge both batteries you would need a second diode.

I may be being a bit paranoid here but that wiring on the diode splitter looks suspicious. I would have assumed, perhaps incorrectly that the RED was the alternator and the Two BROWNS were the batteries. I know the indications are as Paul says, but, Is it worth double checking to confirm where the wires actually go. Just doesn't look right

 

[PaulRainbow]

I may be being a bit paranoid here but that wiring on the diode splitter looks suspicious. I would have assumed, perhaps incorrectly that the RED was the alternator and the Two BROWNS were the batteries. Is it worth double checking to confirm where the wires actually go. Just doesn't look right

The top terminal is definitely the alternator in and the voltage readings with the Stb engine running indicate that it's wired correctly to the alternator. The other two terminals are outputs and the voltages suggest they are connected to the batteries, but there is a significant voltage drop.

I wouldn't get hung up on the wire colours, there shouldn't really be any browns there at all. They may have used red and brown to differentiate the two batteries, but who knows.

That aside, the tests in post #16 will confirm which goes to where.

 

[PaulRainbow]

Thanks Paul.
Off down the boat again this morning, the wife is convinced there is another "she" in my life, which is true in a way.
This time going make sure it is only the alternators putting volts into the system.

The problem is simply that on any decent run ( 7-8 hours from the Mudway to Teddington )the leisure batteries do not appear to be getting charged from the alternators.
As for charging the domestics during a couple of hours a day on tickover while on the Thames, no chance .

Can you also confirm, from post #6 "How are the batteries connected, both engines start from engine batteries, or one from engine battery and the other from the domestics, or what ?"

 

[oldgit]

The latest numbers all taken at 0 degrees centigrade.
Both engines start from the 2 x starter batteries . No start when + terminals removed from both battery posts.

 

[PaulRainbow]

Both alternators appear to be charging OK
The voltage drop from the diode is about what i'd expect, so it looks like that's OK too.

The top brown wire is from the alternator
The middle brown wire is to the engine batteries
The red wire is to the domestic batteries

I don't see anything wrong with the engine batteries voltages, would be better without the diode, but they are also being charged from the port alternator.

The domestic batteries are 50% flat. With a voltage of 12.86, with the diode bypassed, they will never charge much (if at all) past that. The fact that they read 14+ volts on shore power, or when in parallel with the port batteries suggest the batteries are capable of taking a charge.

It's looking like the connection between the diode and the domestic battery is suspect. Can you run a temporary wire from the alternator terminal of the diode to the domestic batteries ? If the engine batteries are close enough to the domestics, you might be able to use the engine battery wire from the diode, just disconnect the domestic wire from the diode and the batteries, then connect the wire from the engine batteries to the domestics.

 

[B27]

It would be useful to know the current going into each battery.
The voltage of a battery can be misleading if you don't know the current.

Also a battery with no current in or out can give a misleading voltage for quite a while after being charged or discharged at all.

How does the generator charge both batteries? Is it an alternator on the genny engine or a charger from the 230V?
Maybe it only charges one battery the 14.5 on the leisure battery could be spurious, stored surface charge from charging it with the shore power? Maybe that's what the 'diode' is for, or maybe the generator has a VSR or similar?

Do we assume the 'shore power' is a dual-output charger?

I'd be re-checking the voltages in the first post, wondering if the starter batteries were still recovering from starting engines when the readings were taken.

It might be useful to measure the voltages across the diode splitter, that will indicate where current is flowing.

Watching for voltages changing over a few minutes can help, as can seeing how they are affected by adding a load like a headlamp bulb.

 

[Alex_Blackwood]

It would be useful to know the current going into each battery.
The voltage of a battery can be misleading if you don't know the current.

Also a battery with no current in or out can give a misleading voltage for quite a while after being charged or discharged at all.

How does the generator charge both batteries? Is it an alternator on the genny engine or a charger from the 230V?
Maybe it only charges one battery the 14.5 on the leisure battery could be spurious, stored surface charge from charging it with the shore power? Maybe that's what the 'diode' is for, or maybe the generator has a VSR or similar?

Do we assume the 'shore power' is a dual-output charger?

I'd be re-checking the voltages in the first post, wondering if the starter batteries were still recovering from starting engines when the readings were taken.

It might be useful to measure the voltages across the diode splitter, that will indicate where current is flowing.

Watching for voltages changing over a few minutes can help, as can seeing how they are affected by adding a load like a headlamp bulb.

Try reading the post before letting your belly rumble!

 

[Refueler]

The alternators are 80A not 50A and both putting about 14.50 V.
Found the Diode thingy (stop me if am getting to technical ) and got the following readings.
View attachment 185657
Why does the splitter appear to be working with one engine but not the other.
Confused of Medway.

I have one of those still fitted to my S25 ... mines from Stirling ... I disconnected it as it had too much of a voltage drop - needed alternator to be cheated or fit a booster.

 

[PaulRainbow]

It would be useful to know the current going into each battery.
The voltage of a battery can be misleading if you don't know the current.

Also a battery with no current in or out can give a misleading voltage for quite a while after being charged or discharged at all.

Seriously ?

How does the generator charge both batteries? Is it an alternator on the genny engine or a charger from the 230V?

It's powering the mains charger, as i said previously and supported by readings given in post #1

Maybe it only charges one battery the 14.5 on the leisure battery could be spurious, stored surface charge from charging it with the shore power?

I'm speechless on this one

Maybe that's what the 'diode' is for, or maybe the generator has a VSR or similar?

I have explained in detail what the diode is for and how it's connected and that's supported by the readings in posts #11 and #25

Do we assume the 'shore power' is a dual-output charger?

Of course it is, otherwise how do you account for the readings in post #1, with the Emg switch off ?

I'd be re-checking the voltages in the first post, wondering if the starter batteries were still recovering from starting engines when the readings were taken.

did you notice #25 ?

It might be useful to measure the voltages across the diode splitter, that will indicate where current is flowing.

Again, have you seen #11 and #25 ?

Have you read any of the previous posts at all ?

It's really useful to read the thread before proffering advice, especially poor advice.

 

[oldgit]

It's looking like the connection between the diode and the domestic battery is suspect. Can you run a temporary wire from the alternator terminal of the diode to the domestic batteries ? If the engine batteries are close enough to the domestics, you might be able to use the engine battery wire from the diode, just disconnect the domestic wire from the diode and the batteries, then connect the wire from the engine batteries to the domestics.

Will be back down boat today clutching a screenshot of post #26.

Easy job to run wire from diode to leisures. About a a metre away and all easy accessible.
Have enough bits left over from a previous life to make up a half decent temporary ? "jump " lead with insulated ring terms on each end.
The installed wiring is of course a labyrinthine nightmare and possibly part of loom with connector block hidden away somewhere.
Will give it a go today.
Thanks again for your interest and time.

 

[Alex_Blackwood]

Both alternators appear to be charging OK
The voltage drop from the diode is about what i'd expect, so it looks like that's OK too.

The top brown wire is from the alternator
The middle brown wire is to the engine batteries
The red wire is to the domestic batteries

I don't see anything wrong with the engine batteries voltages, would be better without the diode, but they are also being charged from the port alternator.

The domestic batteries are 50% flat. With a voltage of 12.86, with the diode bypassed, they will never charge much (if at all) past that. The fact that they read 14+ volts on shore power, or when in parallel with the port batteries suggest the batteries are capable of taking a charge.

It's looking like the connection between the diode and the domestic battery is suspect. Can you run a temporary wire from the alternator terminal of the diode to the domestic batteries ? If the engine batteries are close enough to the domestics, you might be able to use the engine battery wire from the diode, just disconnect the domestic wire from the diode and the batteries, then connect the wire from the engine batteries to the domestics.

For Paul. I am a bit confused with that set of readings and diagram. The Headline states Starboard Engine Only. The diagram then refers to Port alt. Where does the St'bd. one come in. Also some of the readings don't look right. I don't want to start making spurious statements but something just doesn't look right I would have to be doing it myself to be sure.

 

[PaulRainbow]

For Paul. I am a bit confused with that set of readings and diagram. The Headline states Starboard Engine Only. The diagram then refers to Port alt. Where does the St'bd. one come in.

Yes, that was confusing, i took it that the Port alt reading was just that, everything else related to the Stb alternator. The Stb one is taken from the top connection on the diode, although i did ask for it to be taken from the alternator.

Also some of the readings don't look right. I don't want to start making spurious statements but something just doesn't look right I would have to be doing it myself to be sure.

The second picture in post #25 shows that the alternator can raise the engine batteries to 14.06v whilst the domestic batteries are down to about 50% @ 12.06v.

The third picture shows that the engine battery is fully charged, whilst the alternator can only raise the domestic batteries to 12.85v

Both of those are bypassing the diode. I suspect some bad connections between the diode and the domestic batteries, or an issue with the batteries, but previous readings suggest the batteries are OK.

If there isn't an issue with the wiring from the diode to the domestic batteries it would be useful to see a current reading from the OP, as suggested in #27

It would, of course, be easier to be there in person, but i'm not touting for work.

 

[Alex_Blackwood]

Yes, that was confusing, i took it that the Port alt reading was just that, everything else related to the Stb alternator. The Stb one is taken from the top connection on the diode, although i did ask for it to be taken from the alternator.

The second picture in post #25 shows that the alternator can raise the engine batteries to 14.06v whilst the domestic batteries are down to about 50% @ 12.06v.

The third picture shows that the engine battery is fully charged, whilst the alternator can only raise the domestic batteries to 12.85v

Both of those are bypassing the diode. I suspect some bad connections between the diode and the domestic batteries, or an issue with the batteries, but previous readings suggest the batteries are OK.

If there isn't an issue with the wiring from the diode to the domestic batteries it would be useful to see a current reading from the OP, as suggested in #27

It would, of course, be easier to be there in person, but i'm not touting for work.

The second picture in post #25 shows that the alternator can raise the engine batteries to 14.06v whilst the domestic batteries are down to about 50% @ 12.06v.

Yes but the first picture shows the engine batteries @ 14.21 with the diode in circuit and the second is lower with the diode shorted out? I all readings were taken around the same time I would have expected the reverse, no?
I see now where the Port and starb'd are coming from, I think

 

[PaulRainbow]

Yes but the first picture shows the engine batteries @ 14.21 with the diode in circuit and the second is lower with the diode shorted out? I all readings were taken around the same time I would have expected the reverse, no?

I did notice that and thought the same, i've put it down to time differences between the readings and the engine batteries accepting some small charge, but basically fully charged.

I see now where the Port and starb'd are coming from, I think

 

[oldgit]

What difference will this this make ?


Spent a few moments this morning with the multi meter on continuity. and that Diode wiring.

Those Brown wires at top and middle of block go directly to the alternators. !
One Brown to Port Alt and the other Brown to Starboard Alt.

Curiously the Red wire at the bottom terminal appears to have NO continuity to the positive terminals on either Starter or Leisure battery but does give continuity to the negative terminals on the batteries.

 

[PaulRainbow]

What difference will this this make ?


Spent a few moments this morning with the multi meter on continuity. and that Diode wiring.

Those Brown wires at top and middle of block go directly to the alternators. !
One Brown to Port Alt and the other Brown to Starboard Alt.

Curiously the Red wire at the bottom terminal appears to have NO continuity to the positive terminals on either Starter or Leisure battery but does give continuity to the negative terminals on the batteries.

Did you disconnect both ends of each cable to take those readings ?

If the above is correct, the readings in post #25 are impossible, if the circumstances are correct.

When you took those readings in post #25, was the Stb engine the only one running ?

 

[Alex_Blackwood]

Did you disconnect both ends of each cable to take those readings ?

If the above is correct, the readings in post #25 are impossible, if the circumstances are correct.

When you took those readings in post #25, was the Stb engine the only one running ?

Methinks a physical trace of the cables is required! Some notes and drawing along the way? If #36 correct then I think, could be wrong, but, think the readings could be correct. Agree there is some confusion about which, or how many engines were running. I suspect, with all due respect to the OP that we are getting the usual information with the "Unimportant" bits left out.

 

[PaulRainbow]

Methinks a physical trace of the cables is required! Some notes and drawing along the way? If #36 correct then I think, could be wrong, but, think the readings could be correct. Agree there is some confusion about which, or how many engines were running. I suspect, with all due respect to the OP that we are getting the usual information with the "Unimportant" bits left out.

#25 and #36 cannot possibly both be correct. There are several odd anomalies in the readings that have been posted too.

As the current arrangement is poor anyway, it might be worth forgetting about fixing it and just replace it with a better system.

Physically identify the wire from the port alternator and connect it to the engine battery.

Physically identify the wire from the Stb alternator and connect it to the domestic batteries.

So, the port engine charges the engine batteries and nothing else, the Stb engine charges the domestics and nothing else.

Fit a VSR.

Remove the diode and any redundant wiring.

Now, each engine charges all batteries. With both engines running the domestic batteries are getting charged by both alternators. Job done.

 

[Alex_Blackwood]

#25 and #36 cannot possibly both be correct. There are several odd anomalies in the readings that have been posted too.

As the current arrangement is poor anyway, it might be worth forgetting about fixing it and just replace it with a better system.

Physically identify the wire from the port alternator and connect it to the engine battery.

Physically identify the wire from the Stb alternator and connect it to the domestic batteries.

So, the port engine charges the engine batteries and nothing else, the Stb engine charges the domestics and nothing else.

Fit a VSR.

Remove the diode and any redundant wiring.

Now, each engine charges all batteries. With both engines running the domestic batteries are getting charged by both alternators. Job done.

Paul, In #25 in light of #36 Fig 1 appears to be top Brown one alt, output to Red to where? Middle Brown does nothing because of diode but could be showing an alt. voltage?

Fig 2 Both alt's in parallel? (Could be sensing each other) Red wire ? There are no readings in Fig 2/3 for Red wire output?

Fig 3 With top Brown and Red connected seems to have some effect on both batteries, but what?

Otherwise concur with your above.