Battery charger stops working

[Ben340]

Hi all
Thanks for reading in advance

I have a SBC battery charger fitted onboard with a Volvo penta engine/ alternator
The charger works ok on shore power but when I go sailing and use the engine and come back in and re-connect to the shore power the charger doesn’t turn on. After a few days the charger will come back to life, working normally.

The shore power appears to function normally

Any ideas why this might be occuring?

thanks

 

[Boater Sam]

None at all, its illogical. When the charger is not working is there mains present on the input of the charger?

 

[Ben340]

None at all, its illogical. When the charger is not working is there mains present on the input of the charger?

Hi Boater Sam
thanks for the reply.

Yes when connected to shore power there is (according to a 240V tester pen) voltage all the way to the unit. But the unit remains dead.
Have taken it apart and replaced 2 fuses everything else seems intact/in place.

??
thanks

 

[pandos]

Maybe the charger is.sensing that the battery is full...until a few days later when the voltage drops a little.?

Try giving the engine a quick jump of the starter without letting it start and see will the charger come to life...(I do this to see check if it is alive when I cannot hear the cooling fan)

 

[VicS]

None at all, its illogical. When the charger is not working is there mains present on the input of the charger?

Or is the charger being held off by the fact that the batteries are already well charged by the alternator and only "turning on" when the volts have dropped to a threshold. value
I would check the alternator output volts to make sure it is not over charging.

I would also attempt to determine at what point the charger apparently turns itself on. I suspect at some threshold voltage rather than after a set period of time.

Edit . Overtaken by Pandos

 

[Ben340]

Maybe the charger is.sensing that the battery is full...until a few days later when the voltage drops a little.?

Try giving the engine a quick jump of the starter without letting it start and see will the charger come to life...(I do this to see check if it is alive when I cannot hear the cooling fan)

Hi Pandos
thanks for the reply ...will give that a go.
it might be the case but there is a power button and light that is normally on , and a float phase light when fully charged but they are all off...?.. I would have thought the power light would be on even if battery are fully charged ?..
cheers though

 

[Ben340]

Or is the charger being held off by the fact that the batteries are already well charged by the alternator and only "turning on" when the volts have dropped to a threshold. value
I would check the alternator output volts to make sure it is not over charging.

I would also attempt to determine at what point the charger apparently turns itself on. I suspect at some threshold voltage rather than after a set period of time.

Edit . Overtaken by Pandos

Hi VicS
thanks for the reply, will check the alternator again, I checked at idle and seemed to be okay, will check again at higher rpm

there is a power light on the charger which I would think should be on even if not charging ? And a float light phase which I think is on when batteries fully charged

thinking most likely the over charging of the alternator is the problem

thanks for your time n advice

 

[peteK]

I was just about to say the same,maybe when the batteries have dropped to 12.8v or near that the charger will come on.

 

[[70521]]

Hello Ben

I also have a SBC charger and if I plug on the shore power after a motor then there is no charging from the unit.

What lights are being displayed in the unit?

Have you put a volt or multimeter on your batteries before plugging in the shore power? If so what is the reading as soon as you stop the engine and again after an hour or two?

Is the unit switchable between lead acid and AGM/Gel type batteries and have you set it to the same as your batteries.

Sandy

 

[Ben340]

I was just about to say the same,maybe when the batteries have dropped to 12.8v or near that the charger will come on.

thanks PeteK might well be the case gonna try get some readings today and see

 

[Ben340]

Hello Ben

I also have a SBC charger and if I plug on the shore power after a motor then there is no charging from the unit.

What lights are being displayed in the unit?

Have you put a volt or multimeter on your batteries before plugging in the shore power? If so what is the reading as soon as you stop the engine and again after an hour or two?

Is the unit switchable between lead acid and AGM/Gel type batteries and have you set it to the same as your batteries.

Sandy

Hi Sandy
Thanks for the reply - interesting you have a SBC charger aswell.
I must admit I’m not expecting the unit to be charging after a motor as the alternator should have charged the batteries
all I expect is the unit to be on (green power light on) and it to enter a float phase (green light again) indicating batteries are fully charged
However at it stands there are no lights on.

I haven’t put a meter across the batteries after a motor to check but will give that a go hopefully today and see what’s happening there

as far as I’m aware there is no setting to switch between battery types

Have tried to attach a picture of the unit but won’t allow me for some reason - it’s a SBC Quick 501 with the following lights


Green on light with a power on/off switch

Then either a
Red Bulk
amber Absorption
Green Float

Normal if battery low
Green power light
Red bulk or amber light

when battery charged
Green power light
Green float light

but like say at the moment getting nothing at all

thanks again for the reply

 

[Ben340]

 

[LadyInBed]

When it's working on Shore Power ok, what happens if you remove SP, allow things to quiesce for half an hour or so then reapply PS?
Does it behave normally or stay off as per the symptoms you are seeing?

 

[starfire]

Just to throw an observation in.

Those sbc chargers are sniffy about the cooling fan, which has a 3rd wire, similar to computer fans, that tells it the fan is spinning.
No signal from the fan, the charger sulks.

I had one where wire inside the fan had corroded off.