Only charging the starter battery

[Nev]

Hi,

 

Help needed again from you good people. We came aboard yesterday to 100% batteries as reported from the Smartgauge. Ran the engine and the inverter whilst we vacuumed up. The vac is a dyson and whilst running did take the batteries down to 80% then an evening with lights pumps telly for a bit saw the Smartgauge at 76% as we went to bed.

 

Today we have cruised for about an hour an a half... We usually put 10% back on the Smartgauge for every hour we cruise. However the green light constantly flashed and we got nothing back into the batteries.

 

On checking the volts with and without the engine running it is clear the stater is getting a charge and the domestics not. The domestics are reporting about 12.4v both with and without the engine running. The starter is showing about 14.4 v with the engine running and 13.4v without the engine running. All info taken from the Smartgauge

 

I fear we have damaged the charging circuit by drawing too much off the batteries via the inverter to run the vacume cleaner.

 

It is a fairly new alternator replaced a few months ago when we go a charging alarm sound on the way back from Kinver.

 

any advice greatfully received?

 

Thanks

 

Nev NB Waterlily

[Paul C]

Do you have 2 alternators or 1 alternator and a split charge relay? If not, some other type of charging for the domestic (manual switch, or diodes, or smartbank??)

[Wrinkley]

The green light flashing says the battery banks are connected, The voltages you give says they are not. My guess is the relay is not working (wire fell off).

[Guest]

I'm open to correction but I would have thought it extremely unlikely that using the vacuum would have caused this - feels like a co-incidence to me.

[Arthur Brown]

Is it a single alternator setup? What separates the two batteries?

 

As a jury rig you could consider putting a single jump lead from house + to engine + when you next run the engine.

[by'eck]

Unfortunately you give very little information on exactly how your batteries are charged. It appears you have one alternator. If this is correct and its raising the start battery volts to 14.4 volts, it can be assumed that its running correctly.

 

This single alternator will also charge the domestic bank, but via some variety of automatic or manually selectable split charging system such that starter & domestic batteries remain separate when not being charged. It appears you have a failure in this particular system.

 

Its highly unlikely that using the inverter would have caused any harm to this system but clearly more information is needed. However you could initially trace the charge system wiring and check for any blown fuses.

 

Since you have a Smartgauge is it possible you also have the Smartbank split charging system? If so check wiring, any fuses and correct functioning of relay.

[Nev]

Unfortunately you give very little information on exactly how your batteries are charged. It appears you have one alternator. If this is correct and its raising the start battery volts to 14.4 volts, it can be assumed that its running correctly.

 

This single alternator will also charge the domestic bank, but via some variety of automatic or manually selectable split charging system such that starter & domestic batteries remain separate when not being charged. It appears you have a failure in this particular system.

 

Its highly unlikely that using the inverter would have caused any harm to this system but clearly more information is needed. However you could initially trace the charge system wiring and check for any blown fuses.

 

Since you have a Smartgauge is it possible you also have the Smartbank split charging system? If so check wiring, any fuses and correct functioning of relay.

Thank you for all of your very quick and helpful replies. Sorry my initial post was short on detail. Yes it is a single 55amp alternator. Here is the embarrassing bit, not sure how the split charging is handled. I fitted the Smartgauge but the previous owner fitted the Adverc system. What and where should I be looking for the relay as the logic you describe seems to fit the problem. I'll head for the engine hole again to trace all connectors ....

 

Thanks

 

Nev

[Wrinkley]

Sorry gave duff info! Green light flashing system at rest. Green light steady banks connected. Adverc system I had worked with split diode not a relay to control the charging.

[Paul C]

Trace the large wires from the alternator. On my engine, it too has a single alternator but 2 battery banks. There are two thick wires from the alternator (and several thinner ones). One goes to the domestic battery bank, and the other goes to a split charge relay (which is clipped to a bracket bolted to the side of the engine).

[Nev]

Thank you for all of your very quick and helpful replies. Sorry my initial post was short on detail. Yes it is a single 55amp alternator. Here is the embarrassing bit, not sure how the split charging is handled. I fitted the Smartgauge but the previous owner fitted the Adverc system. What and where should I be looking for the relay as the logic you describe seems to fit the problem. I'll head for the engine hole again to trace all connectors ....

 

Thanks

 

Nev

Confidence inspiring... Best thing I can put to this forum.

Just been been back in and found what must be the relay ... Small black box attached to the battery box. Pushed the connectors off and on, started the engine now getting 13.7 v via the Smartgauge. Next job is to remake all the connectors on the relay and allow the solar to trickle charge the batteries back up.

 

Top fellas all of you, good job you are not in the pub otherwise it would be a large round of drinks.

 

More learning done, never stops in my case !

 

Thanks again

 

Nev

 

Edited to say I have run out of greenies for the day... Back tomorrow

Edited November 4, 2012 by Nev

[Iain_S]

(snip)Just been been back in and found what must be the relay ... Small black box attached to the battery box. Pushed the connectors off and on, started the engine now getting 13.7 v via the Smartgauge.

 

If the relay is a "Small black box", it may not be man enough for the job. See Gibbo's relevant page.

 

On the other hand, the flashing green light on the Smartgauge suggests a Smartbank is fitted, so this MAY be the small black box. However, I don't think they have push on connections; if I remember correctly, Smartbank has screwed connections inside the box.

 

Iain