Battery charging problem - Sterling A2B related?

[cpedw]

First trip of the year yesterday and something's not right with the engine's battery charging.

It's a Volvo 2030D with standard alternator (50A I think) and a Sterling A2B fitted 2 years ago. Previously, it has worked fine most of the time. Occasionally, on starting the engine the tacho would not show anything and the A2B would be dead. But a stop, switch off, switch on, restart would always sort it.

Yesterday, the first run needed a restart to get A2B working then the engine ran for about 45 minutes without problem. After a 2 hour sail, restarting the engine the tacho was blank but switching off and on (several times) didn't help. The panel alarm and battery charge light activated too.

Any suggestions where to start checking when I go back with my multimeter tomorrow? It was unusually hot for round here - ambient upper 20s - and the A2B has 3 temperature sensors, internal, alternator and battery. But that must be quite cool for many.

TIA

Derek

 

[William_H]

Without knowing your system I would presume the engine battery is charged by the alternator in the old fashioned way. With B2B operating like a VSR in staying off until engine battery gets to near charged voltage. I think you are saying alternator is not charging so tacho is dead and B2B dormant.
The alternator often is initially fed an excitation voltage from battery via an "ignition" or "alternator warning lamp. So lamp comes on when power is turned on goes out when alternator starts generating and provides its own excitation current. Initially current goes from battery through lamp to regulator (which is in effect conducting current because output voltage is low) to the brushes on the slip ring to the rotating field coils. current in field coils produces magnetism which in rotating generates power.
Now an alternator sometimes has enough residual magnetism in the body of the rotating field coils to actually get alternator up on line. When battery excitation is not working. Sometimes requiring a burst of speed to get it up and running.
Things to check. (assuming sytem is as I think) Does warning light come on on switch on? If not check slip rings and brushes of alternator. (usually under a cover at opposite end to pulley) Also check wiring for voltage supply at both sides of lamp. (lower on regulator side).
You might consider fitting an amp meter to alternator output. This of course could confirm alternator working or not. Or just check engine battery voltage should be around 14v with engine running. Tacho not working of course usually means alternator not charging. ol'will

 

[VicS]

Without knowing your system I would presume the engine battery is charged by the alternator in the old fashioned way. With B2B operating like a VSR in staying off until engine battery gets to near charged voltage. I think you are saying alternator is not charging so tacho is dead and B2B dormant.
The alternator often is initially fed an excitation voltage from battery via an "ignition" or "alternator warning lamp. So lamp comes on when power is turned on goes out when alternator starts generating and provides its own excitation current. Initially current goes from battery through lamp to regulator (which is in effect conducting current because output voltage is low) to the brushes on the slip ring to the rotating field coils. current in field coils produces magnetism which in rotating generates power.
Now an alternator sometimes has enough residual magnetism in the body of the rotating field coils to actually get alternator up on line. When battery excitation is not working. Sometimes requiring a burst of speed to get it up and running.
Things to check. (assuming sytem is as I think) Does warning light come on on switch on? If not check slip rings and brushes of alternator. (usually under a cover at opposite end to pulley) Also check wiring for voltage supply at both sides of lamp. (lower on regulator side).
You might consider fitting an amp meter to alternator output. This of course could confirm alternator working or not. Or just check engine battery voltage should be around 14v with engine running. Tacho not working of course usually means alternator not charging. ol'will

The alternator output is connected to the input of the "alternator to battery charger" (A2B). The unit has 2 outputs. One giving basic charging of the engine start battery, the other advanced charging of the house battery.

.

 

[Alex_Blackwood]

First trip of the year yesterday and something's not right with the engine's battery charging.

It's a Volvo 2030D with standard alternator (50A I think) and a Sterling A2B fitted 2 years ago. Previously, it has worked fine most of the time. Occasionally, on starting the engine the tacho would not show anything and the A2B would be dead. But a stop, switch off, switch on, restart would always sort it.

Yesterday, the first run needed a restart to get A2B working then the engine ran for about 45 minutes without problem. After a 2 hour sail, restarting the engine the tacho was blank but switching off and on (several times) didn't help. The panel alarm and battery charge light activated too.

Any suggestions where to start checking when I go back with my multimeter tomorrow? It was unusually hot for round here - ambient upper 20s - and the A2B has 3 temperature sensors, internal, alternator and battery. But that must be quite cool for many.

TIA

Derek

As it appeared to be, initially, an intermittent fault, it is unlikely to be equipment failure such as diodes etc. I would start by checking all cables and connections to the A-B and alternator. could of course be internal to alternator. (failure of tacho would suggest that). Depending on your expertise and confidence you could check it or have it done by a professional.

 

[jac]

As it appeared to be, initially, an intermittent fault, it is unlikely to be equipment failure such as diodes etc. I would start by checking all cables and connections to the A-B and alternator. could of course be internal to alternator. (failure of tacho would suggest that). Depending on your expertise and confidence you could check it or have it done by a professional.

A2B can also have an additional wire to the starter - unlikely to be the issue here though.

Next time it happens can you check the output from the alternator - If that is dead then the issue is the alternator. Alternatively - have you any other sources of charging voltage that you can supply to the A2B inplace of the ALternator - (i'm thinking Solar) as a test. If that always starts up reliably when it gets a current coming in then that would again point to a problem with the alternator, not the A2B.

 

[Bobc]

Check all connections between the alternator and the instruments. I bet you have a bad connection somewhere. I almost guarantee it won't be anything to do with the A2B unit. Also re-make all your battery connections to ensure they are good.

 

[cpedw]

Update. I disconnected the A2B and connected Alternator output direct to engine battery only. No output from alternator, no tacho and the charge light on Volvo panel stayed on. So I took the alternator off and the local engine guru tested it. It's fine.

Next step is to take the Volvo panel out of the system - connecting a bulb direct between B+ and D+ on the alternator, like the alternator test did.

I have checked that many connections are firm. I could next undo each, clean them up and remake.

I have small solar, 40W I think. Would that be enough to test the A2B function? Since it's already connected to the domestic battery, can I link that direct to the A2B alternator input, disconnecting it from the A2B domestic output and get an A2B test that way?

Tomorrow will be another busy day.

 

[PaulRainbow]

Update. I disconnected the A2B and connected Alternator output direct to engine battery only. No output from alternator, no tacho and the charge light on Volvo panel stayed on. So I took the alternator off and the local engine guru tested it. It's fine.

Next step is to take the Volvo panel out of the system - connecting a bulb direct between B+ and D+ on the alternator, like the alternator test did.

I have checked that many connections are firm. I could next undo each, clean them up and remake.

I have small solar, 40W I think. Would that be enough to test the A2B function? Since it's already connected to the domestic battery, can I link that direct to the A2B alternator input, disconnecting it from the A2B domestic output and get an A2B test that way?

Tomorrow will be another busy day.

No good just pulling on cables. Remove, clean and replace every positive and negative connection between the battery and the alternator. Leave the Volvo panel alone. If cleaning doesn't work, try the bulb straight to the alternator.

 

[VicS]

Update. I disconnected the A2B and connected Alternator output direct to engine battery only. No output from alternator, no tacho and the charge light on Volvo panel stayed on. So I took the alternator off and the local engine guru tested it. It's fine.

Next step is to take the Volvo panel out of the system - connecting a bulb direct between B+ and D+ on the alternator, like the alternator test did.

I have checked that many connections are firm. I could next undo each, clean them up and remake.

I have small solar, 40W I think. Would that be enough to test the A2B function? Since it's already connected to the domestic battery, can I link that direct to the A2B alternator input, disconnecting it from the A2B domestic output and get an A2B test that way?

Tomorrow will be another busy day.

According to the schematic in the owners manual your engine has an excitation resistor which should ensure the initial excitation of the alternator independently of the panel warning light.

Check that resistor and its connections in addition to checking the warning light circuit. The fact that the warning light comes on suggests that its circuit is probably OK but if it is an LED it wont provide enough current .

 

[William_H]

The alternator output is connected to the input of the "alternator to battery charger" (A2B). The unit has 2 outputs. One giving basic charging of the engine start battery, the other advanced charging of the house battery.

.

Thanks Vic yes I did not twig and was not aware of A2B chargers. All part of my education. ol'will

 

[cpedw]

I'm happy to report that all is now working. Although I refitted the alternator and proceeded in cautious stages - Alternator direct to Start battery using a filament bulb D+ to battery + to excite - reconnect volvo panel - reconnect A2B. It worked at each stage so I must assume that bobc and Paul R nailed it - one or more dirty connections got cleaned up in all the disconnecting and reconnecting.

Thanks to all for advice. Now back to sailing ...

 

[PaulRainbow]

I'm happy to report that all is now working. Although I refitted the alternator and proceeded in cautious stages - Alternator direct to Start battery using a filament bulb D+ to battery + to excite - reconnect volvo panel - reconnect A2B. It worked at each stage so I must assume that bobc and Paul R nailed it - one or more dirty connections got cleaned up in all the disconnecting and reconnecting.

Thanks to all for advice. Now back to sailing ...

Good to hear you got it sorted

 

[Bobc]

I'm happy to report that all is now working. Although I refitted the alternator and proceeded in cautious stages - Alternator direct to Start battery using a filament bulb D+ to battery + to excite - reconnect volvo panel - reconnect A2B. It worked at each stage so I must assume that bobc and Paul R nailed it - one or more dirty connections got cleaned up in all the disconnecting and reconnecting.

Thanks to all for advice. Now back to sailing ...

99% of the time it's a dodgy connection in my experience. Glad you got it sorted.