Two way street

Malabarista

Malabarista

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I have a feeling that I am about to be ridiculed. But here goes…
In the interests of a neat installation can i use the main positive busbar ( correctly fused) to connect the output from my sterling (AC) battery charger ( also correctly fused)? Or in other words will the current coming out from the battery bank adversely affect the power coming in from the charger if they share a busbar?
I’m off for my tin hat…
 
Malabarista said:
I have a feeling that I am about to be ridiculed. But here goes…
In the interests of a neat installation can i use the main positive busbar ( correctly fused) to connect the output from my sterling (AC) battery charger ( also correctly fused)? Or in other words will the current coming out from the battery bank adversely affect the power coming in from the charger if they share a busbar?
I’m off for my tin hat…
Click to expand...

You could do that. But the positive busbar is usually wired after the main battery isolator switch, so it would mean that you couldn't charge the battery bank unless you leave it turned on. That's not what a lot of people would want.
 
RichardS said:
It works fine for me ... although I do have two great chunky bus bars (actually I have four) ;)

Richard
Click to expand...

But the point others are trying to make is that if the charger is connected to the main busbar it is not possible to charge the battery when the isolator is OFF.

If it is connected directly to the battery (or the battery side of the isolator) it will be possible to charge the battery whether the isolator is ON or OFF.
 
VicS said:
But the point others are trying to make is that if the charger is connected to the main busbar it is not possible to charge the battery when the isolator is OFF.

If it is connected directly to the battery (or the battery side of the isolator) it will be possible to charge the battery whether the isolator is ON or OFF.
Click to expand...

Yes, I know. :)

My main +ve and -ve busbar are great chunks of copper about 6 in x 1 in x 1/4 in and both are on the battery side of the isolator switch. My mains charger and MPPT controller are both connected directly to these busbars.

Richard
 
Thanks guys.
i should have made myself more clear. From this busbar ( also a chunky one) i am planning to take one bilge pump and the outputs from the solar and ac charger. My dilemma is that would the ingoing and outgoing electrons give me any problems. I promise i did look in all kinds of books but seem to be either too weary ( still at it) or too dumb to find the answer.
 
Malabarista said:
Thanks guys.
i should have made myself more clear. From this busbar ( also a chunky one) i am planning to take one bilge pump and the outputs from the solar and ac charger. My dilemma is that would the ingoing and outgoing electrons give me any problems. I promise i did look in all kinds of books but seem to be either too weary ( still at it) or too dumb to find the answer.
Click to expand...

If the bilge pump is an automatic one controlled by a float switch then the busbar it is connected to should be on the battery side of the battery isolation switch. You can therefore connect the battery charge +ve to and the solar controller +ve to the same +ve busbar and the -ve's to the -ve busbar.

Richard
 
RichardS said:
If the bilge pump is an automatic one controlled by a float switch then the busbar it is connected to should be on the battery side of the battery isolation switch. You can therefore connect the battery charge +ve to and the solar controller +ve to the same +ve busbar and the -ve's to the -ve busbar.

Richard
Click to expand...

Thanks Richard that’s the plan for the morning then.
 
Malabarista said:
Thanks guys.
i should have made myself more clear. From this busbar ( also a chunky one) i am planning to take one bilge pump and the outputs from the solar and ac charger. My dilemma is that would the ingoing and outgoing electrons give me any problems. I promise i did look in all kinds of books but seem to be either too weary ( still at it) or too dumb to find the answer.
Click to expand...

It's no problem the electrons wont have to travel both ways at once

when the load takes more current than the battery charger can supply all the output from the charger will go to the load and the extra required will come from the battery.

If the load takes less than the charger can supply the load will take what it needs from the charger and surplus charger output will go into the battery .

A bit like your car really. When you are stationary and the engine is only idling but you have headlights fog lights, heater blower, heated screen, zillion watt stereo etc all on the alternator probably won't be able to power it all so some( most?) of the current will come from the battery. When you are belting down the motorway the alternator will probably be able to supply all the load with a bit to spare which will go into the battery

( now the pedantic pillocks on here will have a field day picking holes in those explanations!)
 
I went through all this when fitting a solar system and a second AC charger. My layman's conclusion was that everything is connected to everything, and the electrons flow where needed, or are dumped into the batteries as charge - they sort themselves out.

Obviously, if the batteries are isolated, that is not an available route.
 
Thanks again folks. Especially for the complete lack of derision from any quarter. Happy to hear that after hours of scratching my head and thumbing through books it’s an almost normal question.
Much obliged
 
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