# 2x110amp batteries



## dragabed (May 24, 2008)

when wiring 2 x 110 amp batteries which wire goes on first + or --
do you always get that big spark/flash or am i doing something wrong?


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## eurajohn (May 9, 2005)

If you're getting a big spark then you're doing something wrong (unless the battery that is connected to the circuit already is drawing current), Shouldn't matter which you connect first.


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## CheekyDancer (May 10, 2012)

You connect the + first and the - last.


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## andrewball1000 (Oct 16, 2009)

dragabed said:


> when wiring 2 x 110 amp batteries which wire goes on first + or --
> do you always get that big spark/flash or am i doing something wrong?


perhaps it would be best to explain what you are trying to do in more detail. I am guessing (which is dangerous) that you are adding a second 110ah battery to the first? is this the case? If so you need to connect them in parallel rather than series as the latter will give you 24v!!!!!


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## CheekyDancer (May 10, 2012)

Good point that could lead to more serious problems than sparks!

http://www.ms-sportsman.com/details.php?id=323


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## dragabed (May 24, 2008)

yes i am adding another 110 amp battery in parralel not series i have wired the +to + and the earth to, or trying to add the second earth but keep getting big sparks followed clives diagram or think i did (from a previos post)do i have to disconect the existing wires 
they are two new identical batteries and previosly only had one


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## TerryL (Feb 19, 2009)

I believe that if the two batteries are not equally charged - and the only way to be sure is either fully flat (undesirable!) or fully charged - the imbalance of the charge will cause a current to flow one way or the other, causing the sparks. 

If it's Clive Mott-Gotobed's instructions you are following, I think he mentioned it somewhere on the thread. 

Don't forget the fuses - if something IS wrong they should protect you.

Have just had this done to my Bolero, was going to do it myself but decided to leave it to an expert - thanks "Diamond" Dave Newell.

Terry


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## TerryL (Feb 19, 2009)

I believe that if the two batteries are not equally charged - and the only way to be sure is either fully flat (undesirable!) or fully charged - the imbalance of the charge will cause a current to flow one way or the other, causing the sparks. 

If it's Clive Mott-Gotobed's instructions you are following, I think he mentioned it somewhere on the thread. 

Don't forget the fuses - if something IS wrong they should protect you.

Have just had this done to my Bolero, was going to do it myself but decided to leave it to an expert - thanks "Diamond" Dave Newell.

Terry


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## CheekyDancer (May 10, 2012)

The other thing is do not be frighten of a little sparking. If you are sure they are wired correctly get them on and tightened. A little Vaseline or Hydrofuge is always good for the terminals as well to prevent corrosion.


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## eurajohn (May 9, 2005)

Sorry but unless the OP is exaggerating the size / type of spark then it is not simply one battery charged more fully than the other, to my mind that type of reaction can only be caused by a dead short. I'd suggest that he disconnects the battery that is (or at least must be) connected to the service on the van and then try to do what he had previously attempted and see if he gets the same reaction.
I do agree that it is technically correct to connect the earth pole last but in reality unless there is another problem it should make no difference which is connected first when adding a second unit, as you are completing the circuit whichever is completed first.


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## CheekyDancer (May 10, 2012)

Always connect your ground last. 
The reason for connecting the ground last is, if the ground cable is hooked up 1st, when you attach the positive cable, if the wrench hits something grounded (like a bolt on the frame), you'll spark big time. The bigger problem is that a charging battery emits hydrogen gas (ever hear of the Hindenburg?), and the spark could set it off.


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## dragabed (May 24, 2008)

hi and thanks for all your replies. 
this is what i am going to attempt today 
i have three batteries 
1-starter battery 
2- existing new 110amp leisure battery 
3-additional 110amp battery identical and bought at the same time as battery 2. 
A - disconnect both terminals of battery 2. 

B- make up two leads with heavy cable similar to jump cable size one end of each with battery terminals, other end with O connector. 

C-fit the two ends with battery connector to battery 3 and tighten. 

D- connect + terminal coming from battery 3 to loose cable of battery 2 and the same for the negative cable. 

E- reconnect positive to battery 2, reconnect negative to battery 2. 
and pray it all works 
then off to france for two months and connect new solar panel while away or on return.


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## dragabed (May 24, 2008)

success and thanks again


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