# Linking leisure batteries in parallel



## dpsuk999 (Mar 25, 2012)

Hi, there seems to be a few different ways that people use to link their leisure batteries in parallel. Just wondered what peoples views are?

Take a look at this interesting site which goes into a lot of details and advise which method you use, 1, 2, 3 or 4.

http://www.smartgauge.co.uk/batt_con.html


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## listerdiesel (Aug 3, 2012)

There was a big discussion on here a month or so back.

My personal preference is a straight parallelling with decent quality leads.

Peter


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## WildThingsKev (Dec 29, 2009)

I use method 2 but since I have starter cable between the batteries it is probably equivalent to 3 as well.

2 x 110Ah.

Kev


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## drcotts (Feb 23, 2006)

I use method one.
Bear in mind that you wont be drawing 100amps!! unless your starting the engine with a leisure battery.

Only when 100 amps is drawn that you will have the type of figs reported. if you were drawing the type of current seem in a MH then the figures would be much more equal. Especially if you have decent leads. 

If this is correct why dont the manufacturers wire them up like this.

Phill


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## Fatalhud (Mar 3, 2006)

Started off with method 1, but voltage would drop off quickly with blow air heating running.
I now use method 2 and blow air lasts a hell of a lot longer

Although the example is 100A you still get the same effect with lower current draw

Others disagree but I can only report on my own personel results :wink: 

Alan H


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## dpsuk999 (Mar 25, 2012)

Interesting how people's views that if they don't draw 100 amps immediately then the science behind battery health isn't applicable. Surely if for example you have a couple of lights on, tv on and blown air heating, over the course of the evening or weekend you will draw in excess of 100 amps so isn't it worth doing the wiring as in method 3 or 4?

And following on from Phil's question about why don't manufacturers do it the 'correct way' in my experience alot of new mh only have 1 leisure battery and it's successive owners who add more batteries and just wire them up as in method 1 because of a distinct lack of a definitive PROVEN way of doing it??


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## drcotts (Feb 23, 2006)

dpsuk999 said:


> Interesting how people's views that if they don't draw 100 amps immediately then the science behind battery health isn't applicable. Surely if for example you have a couple of lights on, tv on and blown air heating, over the course of the evening or weekend you will draw in excess of 100 amps so isn't it worth doing the wiring as in method 3 or 4?
> 
> And following on from Phil's question about why don't manufacturers do it the 'correct way' in my experience alot of new mh only have 1 leisure battery and it's successive owners who add more batteries and just wire them up as in method 1 because of a distinct lack of a definitive PROVEN way of doing it??


Hi dpsuk999
Amps is the *rate *that current is drawn not not the amount so if you draw 25 amps or whatever then it doesnt matter how long you draw it for it wont make the battery last any longer or shorter.

I do understand the theory shown in the link but its only proven by an example of measuring 100 amp draw. This may not happen if 10 amps was being drawn as the current would have better chace of being equalised. And it has one fundamental flaw in that its assumed that 25 amps is drawn from each battery to deliver 100amps at the terminals.
I dont think this is "stricly" correct.

Phill


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## oldun (Nov 10, 2005)

drcotts said:


> dpsuk999 said:
> 
> 
> > Interesting how people's views that if they don't draw 100 amps immediately then the science behind battery health isn't applicable. Surely if for example you have a couple of lights on, tv on and blown air heating, over the course of the evening or weekend you will draw in excess of 100 amps so isn't it worth doing the wiring as in method 3 or 4?
> ...


 I don't understand what is being said here.

Amps is the current drawn NOT the rate at which the current is drawn.

Amps is a measure of currents!!!!

What does "rate of current drawn" mean?


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## rayc (Jun 3, 2008)

oldun said:


> drcotts said:
> 
> 
> > dpsuk999 said:
> ...


Amps is a rate of flow i.e number of particles (charged) transiting per unit time. 1 amp = 6.241 × 1018 electrons, or one coulomb per second passing a point in an electric circuit.


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