# Another battery question



## redjumpa (Sep 5, 2008)

I have two 75w solar panels and only one 90amp battery (all on when the van was bought) I want to add 2 x 110amp batteries but have the following question.

The current solar system has a duel regulator that tops the engine battery up when the leisure battery is full (i think!!)

Queston........... when I have two new leisure batteries fitted will I still be able to charge the engine battery from the solar using the duel regulator? Does duel mean two batteries or do the new leisure batteries act as one and the engine still top up. 

Sorry it's a bit garbled ........... combination of being a newbie and knowing nothing about electrics.


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## TDG (May 26, 2009)

Your two new leisure batteries connected in parallel will act a single battery and your engine battery will still get charged but if using the full capacity of the new ones the engine battery might have wait a long time! Don't forget, the solar cell power you quote is the nominal maximun rating but on average on a 24 hr basis they they probably only output about 30% of the maximum.
Regards,TDG


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## weldted (May 1, 2005)

*battery connection*

Hi there, when you install the new leisure batteries be sure to connect the + positive terminal of one to the + positive terminal of the other and the 
- negative terminal to the other other negative terminal this will give you twelve volt 220 amp hour capacity and with a heavy enough cable to avoid voltage drop although the batteries are close together cable size is important to get the best results from your batteries, 25mm sqr cable would be ideal with good quality crimp terminals, it does not matter which one of the batteries you connect the cable from the van to but make sure all 12 systems are turned of to avoid the risk of sparks and make sure the batteries are in a vented compartment as the gas is highly explosive. This should not interfere with the exsisting system to top up your engine battery, if you have a battery mate or similar all that happens is when the leisure battery or batteries is approx one volt higher than the engine battery it with allow a small current to trickle charge to keep the engine battery topped up.


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## weldted (May 1, 2005)

*new batteries*

Hi again just a thought are you replacing your original battery with the new ones or adding them on. The reason I ask is when replacing batteries if you do not replace them all at once they will be pulled down to the worst performing one. I have two spr 90wt solar panels fitted and the best out put this time of the year is a max 7.3 amps but only when the sun is at its peak on a clear cool day, solar panels efficiency is reduced as the temperarture rise also keep them clean as a small amount of dust has a marked effect, if you put your hand over a small area of the panel watch the output drop.


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## CliveMott (Mar 10, 2008)

A bit more on here :-
http://www.motts.org/second leisiure battery.htm
c.


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## TDG (May 26, 2009)

weldted, 
If your 2 x 90 watt panels are only outputting a maximum of 7.2 amps, under near perfect conditions, then they are only delivering about 50% of their "rated capacity" ! That being the case, they would be be outputting half of dam all this morning in North Devon.
Best regards,
TDG


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## time-traveller (Apr 23, 2007)

redjumpa said:


> I have two 75w solar panels and only one 90amp battery (all on when the van was bought) I want to add 2 x 110amp batteries but have the following question.
> 
> The current solar system has a duel regulator that tops the engine battery up when the leisure battery is full (i think!!)
> 
> Queston........... do the new leisure batteries act as one and the engine still top up.


The simple answer without going off on a tangent is ...... yes


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## TDG (May 26, 2009)

time-traveller said:


> redjumpa said:
> 
> 
> > I have two 75w solar panels and only one 90amp battery (all on when the van was bought) I want to add 2 x 110amp batteries but have the following question.
> ...


But.......... without all the tangents this forum generates, it would be shadow of its present form. Mind you, that would cut out a lot of the c**p that appears. However, in amongst all the c**p, there is a lot of good and interesting stuff.
TDG


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## erneboy (Feb 8, 2007)

One mans c..p, etc.


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