cable from solar controller to battery

I take it you mean the short run of cable from the regulator to the battery terminal. Most regulators can not handle large wire diameters. 2.5 mm sq should be sufficient.
 
maingate said:
I take it you mean the short run of cable from the regulator to the battery terminal. Most regulators can not handle large wire diameters. 2.5 mm sq should be sufficient.
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If loads are being taken from the regulator (which they be should to protect the battery) or the cable run from the regulator to the battery is more than a foot then 6mm2 is the cable you need, whilst not all regulators will allow a cable of this size to be connected a decent one up to the job should, besides the cable can easily be reduced in size to fit the regulator by removing a few strands. this will not compromise the ability of the rest of the cable to withstand cable losses. Bigger cable the better.
 
wildman said:
If loads are being taken from the regulator (which they be should to protect the battery) or the cable run from the regulator to the battery is more than a foot then 6mm2 is the cable you need, whilst not all regulators will allow a cable of this size to be connected a decent one up to the job should, besides the cable can easily be reduced in size to fit the regulator by removing a few strands. this will not compromise the ability of the rest of the cable to withstand cable losses. Bigger cable the better.
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Totally disagree unless you have around 500 Watts of solar.
 
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My Schaudt 1218 regulator can handle 18 Amps from the panels. The wiring supplied with it is nowhere near 6 mm, it is not even 2.5 mm sq. If the manufacturers do this then I would totally ignore any information from amateurs on forums. They may be well meaning but do not have any idea what they are talking about. They are probably confusing the cable size needed from the panels TO the regulator rather than that needed FROM the reg to the battery/ies.

Anyway, my setup is installed and working fine so I will bow out of this discussion before an argument starts. Bye bye. :wave:
 
maingate said:
They are probably confusing the cable size needed from the panels TO the regulator rather than that needed FROM the reg to the battery/ies.
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Like you, I'm not wishing to get into an argument but why would the cable be a different size from the panels to the reg than from the reg to the batts? The reg is to drop the voltage, it shouldn't be dropping the current. I'm intrested in this because it may be a route I shall go down.
 
Cables designed for domestic fixed wiring installation should not be used as they are too rigid which will result in cores breaking due to vibration. Cores should not be cut off in order to make a connection fit. The current capacity of a cable is with all cores terminated and used.
 
So what size cable will be needed on this ?
 

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starburst said:
cable from solar controller to battery
I have A solar kit on its way but have
been informed that the cable from solar
Controller to battery is not included,
can anyone tell me what cable i will
need, the kit is 2 X 85w panels to the
controller.
Click to expand...

I have calculated my set up thus:

100w Solar panel =
Watts to amps (A) conversion calculator
This says I would get 8.3333333 amps.
Using the Wire Gauges table
Amps and Wire Gauge - 12V Circuit
For 15 to 20 feet is 12 AWG
Using another table
Wire Gauges
This then tells me I requires 3.3mm sq cable.
Always go to the nearest higher cable for your installation.

Having calculated the above, I have been using 2.5mm Sq for the past two years.
 
Beemer said:
I have calculated my set up thus:

100w Solar panel =
Watts to amps (A) conversion calculator
This says I would get 8.3333333 amps.
Using the Wire Gauges table
Amps and Wire Gauge - 12V Circuit
For 15 to 20 feet is 12 AWG
Using another table
Wire Gauges
This then tells me I requires 3.3mm sq cable.
Always go to the nearest higher cable for your installation.

Having calculated the above, I have been using 2.5mm Sq for the past two years.
Click to expand...

With all this present day talk about huge cables, it's a wonder you and I ever got any charge in our batteries. :p :lol-049:
 
Beemer said:
I have calculated my set up thus:

100w Solar panel =
Watts to amps (A) conversion calculator
This says I would get 8.3333333 amps.
Using the Wire Gauges table
Amps and Wire Gauge - 12V Circuit
For 15 to 20 feet is 12 AWG
Using another table
Wire Gauges
This then tells me I requires 3.3mm sq cable.
Always go to the nearest higher cable for your installation.

Having calculated the above, I have been using 2.5mm Sq for the past two years.
Click to expand...

Another fly in the ointment - isn't the ouput from the panels around 18v? hence the reg to drop it to around 14.4v in this case a little over 5A, or am I way off the mark?:)
 
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sparrks said:
Another fly in the ointment - isn't the ouput from the panels around 18v? hense the reg to drop it to around 14.4v in this case a little over 5A, or am I way off the mark?:)
Click to expand...

Correct, the solar panel output is at the output voltage 18-19 volts ish so as you say the max current is say 5.5A

If there is a slight voltage drop between panel and regulator, so what?? It makes the regulators job easier, as long as you get say 15volts at the input of the regulator then everythings OK.

What is more critical is the distance between the regulator and the batts, as close as possible. A couple of foot of wire at 5A won't give much of a volt drop, so in modest configs a 2.5mm cable is prob OK.

NB, The negative from the solar panel is not always the same potential as the negative of the battery, many regulators use the negative supply lead for regulation. (N channel MOSFETS have lower ON resistance than P Type).
 
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