Sterling ABC AB1280 charger and 1,2,both,off type switch

[Billows]

Anyone have the above combination? I am puzzled as to how the above combination would be wired.In the wiring instructions it says...
'If you currently have a split charge diode, then the three positive wires are already
there. Simply replace the split charge diode with the alternator-to-battery charger.'

If it replaces the diodes the switch set to 2 will put a short across the charger from input (alternator) to output (house battery) as happens with a simple split charge diode. Similarly switch set to 1 will put a short across the charger from input (alternator) to output (start battery). Does this mean the charger boosts only if the switch is off? What is the correct switch procedure?

 

[lpdsn]

Anyone have the above combination? I am puzzled as to how the above combination would be wired.In the wiring instructions it says...
'If you currently have a split charge diode, then the three positive wires are already
there. Simply replace the split charge diode with the alternator-to-battery charger.'

If it replaces the diodes the switch set to 2 will put a short across the charger from input (alternator) to output (house battery) as happens with a simple split charge diode. Similarly switch set to 1 will put a short across the charger from input (alternator) to output (start battery). Does this mean the charger boosts only if the switch is off? What is the correct switch procedure?

Easiest way is to bin the 1-2-both switch and replace it with separate on-off switches for the engine battery and the domestic battery. The A-to-B charger has a different regime for engine and domestic batteries anyway, so won't be providing the same voltage on each output, so you don't want to short them.

There's a circuit diagram in the instructions (was for mine anyway). The alternator +ve output should go to the charger. I had to remove the direct connections from the regulator to the batteries and you may well have to do this too.

The separate outputs from the charger go to the respective batteries (or banks).

-ve wiring is easier, but you still need to connect the charger to the -ve (this takes much less current that the +ve inputs and outputs though as the battery negatives are still connected to the regulator).

PS you don't need to charge through the switches, so can avoid the risk of a crew member (or skipper ) accidentally turning them off.

 

[prv]

Why do you want to use both an ABC and an old-fashioned switch? In the standard configuration for each they are mutually exclusive.

I guess you could recycle the switch for an emergency engine start or other odd combinations if you insisted, but if you don't already have a firm idea of what you want to do with it then the answer is probably "remove it".

Pete

 

[VicS]

Anyone have the above combination? I am puzzled as to how the above combination would be wired.In the wiring instructions it says...
'If you currently have a split charge diode, then the three positive wires are already
there. Simply replace the split charge diode with the alternator-to-battery charger.'

If it replaces the diodes the switch set to 2 will put a short across the charger from input (alternator) to output (house battery) as happens with a simple split charge diode. Similarly switch set to 1 will put a short across the charger from input (alternator) to output (start battery). Does this mean the charger boosts only if the switch is off? What is the correct switch procedure?

If you have a split charge diode system then the old 1,2 both switch should probably have been flung out when the diode splitter was fitted.


Sterling's description is a bit "slick". Seems to be his style.


1nstall your AB charger as per the full instructions, separating your domestic and engine start systems. Starter circuit fed from the starter battery and domestic systems fed from your domestic battery via separate isolators


You can as suggested retain the 1, 2 both switch to select which battery to use for engine starting but it should be wired between the two isolators to the engine start circuit. Normally you'd leave it set to use the starter battery.

The only thing connected to the alternator output should be the AB charger

Now is the time to make a proper job of the battery wiring, getting away from this halfway-house set up with selector switch and diode splitter.

 

[William_H]

OP asks what is the correct switch procedure? That is hard to answer without knowing how the 1,2,both switch is wired. other posters have suggested ways of modifying the system. I would tend to agree. However OP probably needs to carefully figure out what has been done already. I can only suggest some arrangements and hopefully one might appear to be the present set up.
Idealy the 1,2,both switch would relate only to multiple house batteries. Where others will just parallel them. So normal operation would be on both. This would leave the engine battery connected dirrectly to the engine and alternator. The ABC would go to the domestic batteries via the 1,2,both switch. "off would be used when leaving the boat.You may or may not have an isolation switch for the engine battery.
Test.. can you start the engine with 1,2,both switch "off" if so maybe as above. If not then engine battery goes through 1,1,both switch.
2nd test... does domestic battery voltage rise with engine running with 1.2.both switch off? if not OK if it does then see below.

One simple way to use a ABC would be to take the standard regular 1,2,both switch wiring. Start the engine on eg no 1 and leave switch on 1. If 2 is domestic battery then ABC is connected to give charge to domestic no 2. You would have to always have no 1 as engine battery. Problem with this arrangement is that if you switched to "both " with engine charging you are going to negate the added voltage of the ABC. In effect short output to input probably smoking the ABC. (hopefully taking out a fuse)
These are just 2 options just try to igure out what happens. good luck olewill

 

[VicS]

Anyone have the above combination? I am puzzled as to how the above combination would be wired.In the wiring instructions it says...
'If you currently have a split charge diode, then the three positive wires are already
there. Simply replace the split charge diode with the alternator-to-battery charger.'

If it replaces the diodes the switch set to 2 will put a short across the charger from input (alternator) to output (house battery) as happens with a simple split charge diode. Similarly switch set to 1 will put a short across the charger from input (alternator) to output (start battery). Does this mean the charger boosts only if the switch is off? What is the correct switch procedure?

On reflection, and having re-read the original question it would be possible to retain the existing selector switch, using it to select the "duty" battery in much the same way as at present.

What you will have to do, and this should have been done when the diode splitter was installed, is to disconnect the existing alternator output wiring (it probably joins up with everything else at the starter solenoid) and instead connect it directly to the input terminal of the ABC as shown in the installation instructions for the ABC
Depending on how it is wired you may also have to transfer any other engine wiring that may be connected directly to the alternator output to the battery connection on the solenoid.

 

[Billows]

Guess I will have to trace the wiring to see how the 1,2,both switch and charger is arranged at the moment to figure out how best to operate the switch. Has anyone got a wiring diagram showing how start battery, house battery, 12,both 3 pole switch, alternator, sterling charger , panel, engine panel and starter solenoid should best be wired? This must be a common problem when installing these chargers.

 

[prv]

Has anyone got a wiring diagram showing how start battery, house battery, 12,both 3 pole switch, alternator, sterling charger , panel, engine panel and starter solenoid should best be wired? This must be a common problem when installing these chargers.

No, because combining a Sterling ABC charger and a 1-2-both switch is not a normal thing to do. I still don't understand why you're insisting on doing it.

What you should have is the starter battery connected to the starter motor, the service battery connected to the distribution panel, each via an on/off isolator (you can get a neat switch which contains two electrically-separate but mechanically-linked isolators for this purpose). That constitutes the load side - two separate circuits not involved with each other at all, always a fresh engine battery ready to start which can't be run down by the fridge.

Then the charging side consists of a cable from the alternator to the Sterling ABC, a cable out from the ABC to the starter battery, and another cable out from the ABC to the service battery. The ABC ensures that one can't back-feed into the other, and charges them efficiently by whatever fancy process Mr Sterling has dreamed up.

You might in addition want an emergency parallel link between the battery banks, although with a decent charger and a separate engine battery the odds are it will never be used. This is just a third on/off switch (use the same type as the isolators) in the middle of a link wire from starter battery to service battery. Or, if you use the combined-but-separate isolator style I mentioned above, Blue Sea make one with this link switch built in which is particularly neat and saves some wiring. Or just tuck a single jump lead away in a locker somewhere - as I say, with the engine battery safe from the fridge/radar/autopilot, you should never flatten it and never need the link.

There is no place for a 1-2-both switch in this scheme, stop trying to squeeze one into it.

Pete

 

[JumbleDuck]

If you have a split charge diode system then the old 1,2 both switch should probably have been flung out when the diode splitter was fitted.

I thought a common use for a diode splitter was to combine it with a 1-2-Both switch to make sure both batteries were charged regardless of switch position.

 

[prv]

I thought a common use for a diode splitter was to combine it with a 1-2-Both switch to make sure both batteries were charged regardless of switch position.

Then what's the switch for?

Pete

 

[Pye_End]

Guess I will have to trace the wiring to see how the 1,2,both switch and charger is arranged at the moment to figure out how best to operate the switch. Has anyone got a wiring diagram showing how start battery, house battery, 12,both 3 pole switch, alternator, sterling charger , panel, engine panel and starter solenoid should best be wired? This must be a common problem when installing these chargers.

From what I remember, it is not compulsory to use both outputs from the AB charger.

Mine has one output directly onto the house batteries, and I currently do not use the other. I sometime use the 1-2-both on 'both' to charge the engine battery for a while, but this does not take much charging - the house needs much more time.

You could presumably put one set of outputs onto the house bank, and the other onto the engine battery, but I am not sure if there would be any issues if 'both' were selected whilst charging (not that there would be any need to select both).

 

[JumbleDuck]

Then what's the switch for?

So you don't run down the starter battery with domestic use.

I prefer having two independent circuits, and refitted my boat with the Blue Sea dual+parallel switch last year.

 

[prv]

So you don't run down the starter battery with domestic use.

But with a diode splitter, the only way you could connect the starter battery to domestic users is through the thrice-accursed switch! So you fit it to simultaneously introduce and sort-of-solve a problem that wouldn't otherwise exist?

Pete

 

[pvb]

Guess I will have to trace the wiring to see how the 1,2,both switch and charger is arranged at the moment to figure out how best to operate the switch. Has anyone got a wiring diagram showing how start battery, house battery, 12,both 3 pole switch, alternator, sterling charger , panel, engine panel and starter solenoid should best be wired? This must be a common problem when installing these chargers.

You could rewire to keep your 1-2-Both switch, but using it only to connect the starter battery to the engine. Then you also need a second simple on/off switch to connect the house battery bank to the domestic fuse panel. The AB charger takes the alternator output and supplies it (boosted) to the house batteries and (unboosted) to the starter battery - these are isolated outputs so there's no need for a diode splitter.

For years in these forums, I've put forward the view that the antiquated 1-2-Both switch has no place on a boat these days. There are much better solutions which require no attention, keep the batteries properly charged, and can't be accidentally set in the wrong position. I've usually been shot down by people who are resisting the concept of living in the 21st century, but I think the message is slowly getting through.

 

[prv]

You could rewire to keep your 1-2-Both switch

But why? Sure, it can be used as a confusing stand-in for an on/off isolator, but unless the thing is a treasured family heirloom kept on the boat for sentimental reasons, what on earth would be the point? Even on a shoestring budget (which the OP isn't, or he wouldn't be buying the Sterling) it doesn't make sense when an isolator is £7.50 delivered and some other luddite would probably buy the 1-2-both for £15 (half retail).

Pete

 

[pvb]

But why? Sure, it can be used as a confusing stand-in for an on/off isolator, but unless the thing is a treasured family heirloom kept on the boat for sentimental reasons, what on earth would be the point? Even on a shoestring budget (which the OP isn't, or he wouldn't be buying the Sterling) it doesn't make sense when an isolator is £7.50 delivered and some other luddite would probably buy the 1-2-both for £15 (half retail).

Yes, but removing a 1-2-Both switch tends to leave an ugly hole in the woodwork! And, as the OP seems quite attached to it, I thought I'd suggest a possible use for it.

 

[Pye_End]

I've usually been shot down by people who are resisting the concept of living in the 21st century,

Personally, I do not find 1-2-both a problem, so find no need to solve a problem that is not there in the first place. Maybe if starting from scratch I might do it differently, but feel no need to rip out something that works perfectly well.

 

[pvb]

....something that works perfectly well.

As long as you keep remembering to put it on the correct setting!

 

[prv]

Yes, but removing a 1-2-Both switch tends to leave an ugly hole in the woodwork!

The switches themselves are generally unnecessarily ugly, so even if you just replace it with a simple square of ply screwed over the hole, the net result is still an aesthetic improvement

And, as the OP seems quite attached to it, I thought I'd suggest a possible use for it.

I don't think he's sentimentally attached to the switch per se, I think he's just a bit confused about what he's trying to achieve.

Pete

 

[Boo2]

...There is no place for a 1-2-both switch in this scheme, stop trying to squeeze one into it.

In the case where the house bank is comprised of 2 separate batteries a 12BO switch can be used in place of 2 isolator switches and this is the system Sunrunner now has.

Boo2