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Post Info TOPIC: another battery question


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another battery question


hi all 

i want to put another battery in the van

there is one on the right hand side under the bed

i was thinking of putting this one in the left hand side under the bed

"question"

can i do this and just use longer cables

and if so is that ok .

"question 2 "

the cables is it just + to +

                             - to -

there is another quesion but ill wait until i get an answer on these

as it might be answered some were along the line 

thanks in advance 



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Yes you can, BUT....
The cables need to be appropriately sized - that means BIG. I suggest 35mm2.
For safety you should fuse the active cable at BOTH ends, near each battery. I suggest manually resettable circuit breakers of say 50A minimum (depending on what loads you intend to draw from the batteries).
Cheers,
Peter

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It would be better to run the cable to positive on one battery & negative to the other. If you have a light load & charging I wouldn't worry too much. But at least put heavy gauge cables between the two batteries.



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Whenarewethere wrote:

It would be better to run the cable to positive on one battery & negative to the other.


That is very misleading unless you describe WHICH cables you are talking about as it could mean that you are suggesting that the batteries be wired in series which the OP does NOT want to do.

Cheers,

Peter



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thanks Peter

didnt give a breaker a thought 

better be safe then sorry 

ill chuck one on 



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Whenarewethere 

thanks Whenarewethere

so your saying + on the new battery to- on the older battery

and - on the new battery to + on the older battery 

also while im picking brains

at the moment everything [ wiring] is running to the older battery

all the + wires to the + on the battery

and all the - wires to the - on the battery

should i once i put the new battery in 

should i run the + wirering to the + on say the older battery

and the - wires to the - on the newer battery 

that way they are both [ batterys ] are working the same ?????????????

i really hope that that makes some sence 



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It is not misleading because if the other cables are not there the battery is disconnected.

Anyway I have got 2 x 26 AH batteries connected as I suggested. Later I added a third 26 AH battery & added it simply connected to the first 2 batteries so I have a combination of both. I am only running a fridge & only have a 120 solar panel so I am not going to stress about the situation.

The only time is if I use the 3 batteries to run my compressors at 100 amps or backup jump starting. But for the short runs using 6AWG it is not worth stressing over.

As said earlier, since you are running new cable to the new battery the extra cost of overkill cable costs less than the time doing the job. Do that part right for the future. Put in heavy cable & colder all the connections. If your soldering iron is a bit under size, drill a hole in a block of wood to hold the connector, which in itself helps reduces heat loss. 120 watt soldering iron is boarder line for 6AWG wire.



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Don't ya just hate it when a post just goes off into the ether.
I'll try again, when connecting a 12v battery to another 12v battery so you still have a 12v system, big cables and positive to positive and negative to negative.
As far as the 2 cable, one going to the negative on one battery and the other going to the positive on the other battery, this is referring to the load/charging cables. The idea is to share the charging and load across the 2 batteries. It is still a compromise, but a lot better than connecting the load/charging to one battery and just piggy backing the second battery to it via long leads.

T1 Terry

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My dog's breakfast but I am not stressing out over it as I am only running a fridge typically 2.5 to 3.1 amps, so about an amp per battery. Charging off solar or car 8 to 10 amps, so about 3 amps per battery, all 6AWG 3 metres (6 metres +&- )

Battery001.gif



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Procrastination, mankind's greatest labour saving device!

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Trouto

 

Please read this    easy to understand.

 

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

 

Cheers Baz



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Thanks Baz

and thanks to everyone that answered

tomorrows project 



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This works. I wired it myself.

Regards.

Hetho



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Hetho wrote:

This works. I wired it myself.

Regards.

Hetho


Curiosity here,,,, what current in/out is that wiring rated at???? 



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If you wire 2 x 120 Ah batteries

+ to - on both batteries you will end up with 24 v at 120 Ah which is series.

If you wire the same batteries

+ to +
- to - you will end up with 12 v at 240 Ah which is parallel

which is the preferred way for caravans.

Cheers Bob

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Yep cable is a little light between batteries . But Id load is taken evenly off both ? Its not an issue . Besides total amperage possibly is that high its storage over time ( A/H ) your really after .

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Aus-Kiwi wrote:

Yep cable is a little light between batteries . But Id load is taken evenly off both ? Its not an issue . Besides total amperage possibly is that high its storage over time ( A/H ) your really after .


 Not the way it is wired in Hetho's photos, one battery is doing the work and the other battery is just piggy backing off it. Just because the voltage is the same doesn't mean the load is the same on both batteries nor will the state of charge be the same. The high internal resistance in a lead acid battery is the reason why such a set up will not load share. I think the Smartgauge article Baz421 liked to explains what will happen and the better way to wire it.

 

T1 Terry

Sorry, auto correct messed with Aus Kiwi's post I quoted so I changed it back



-- Edited by T1 Terry on Sunday 27th of January 2019 06:27:21 PM

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Any links to any sites or products is not an endorsement by me or do I gain any financial reward for such links 



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T1 Terry wrote:
Aus-Kiwi wrote:

Yep cable is a little light between batteries . But Id load is taken evenly off both ? Its not an issue . Besides total amperage possibly is that high its storage over time ( A/H ) your really after .


 Not the way it is wired in Hetho's photos, one battery is doing the work and the other battery is just piggy backing off it. Just because the voltage is the same doesn't mean the load is the same on both batteries nor will the state of charge be the same. The high internal resistance in a lead acid battery is the reason why such a set up will not load share. I think the Smartgauge article Baz421 liked to explains what will happen and the better way to wire it.

 

T1 Terry

Sorry, auto correct messed with Aus Kiwi's post I quoted so I changed it back



-- Edited by T1 Terry on Sunday 27th of January 2019 06:27:21 PM


Agree Terry.  I learned this lesson in the 80's on my yacht,,, kept killing one battery in bank of 3 ,,, 2 year warranty in those days,,, dealer told me to f*** off in the end.

Also I don't like 2 wires joined to take current,,, experience in real life too,,,,, only takes a low resistance in one wire to overload  wire,,, ie create hotspot,,, there fore a risk IMHO



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Ahh . If load is taken off the centre no issue . What I meant buy fitting cables so pulls off each battery, load balancing . Works the same when charging . One pic the cable was smaller . Of course it depends on total load ? But most are low amperage over time as in TVs, lights etc . With enough solar, good regulator ? Shouldnt have issues . Often wander when motor batteries are connected via VSR it effects balance ? Between the two types of batteries .

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