Wire Gauge from Battery to Charge Controller

[SoulRaven]

Hi there.  All I plan to use on my house battery is my laptop (max 8 hours a day) and possibly an external monitor.  Yesterday, I purchased a 50 amp hour AGM battery and connected my inverter to that with 4 gauge (too small?) (I had the inverter already.) 

I'm planning on buying this charge controller:
https://www.amazon.com/gp/product/B01MU0WMGT

And this solar panel:
https://www.amazon.com/gp/product/B013E07FNM

My question is what size wire do I need from the battery to the charge controller?

 

[highdesertranger]

how many watts is that inverter? that appears to be 10 gauge wire not 4. 12 or 14 will work from the charge controller to the battery, but if it was me I would use 10 gauge. highdesertranger

 

[SoulRaven]

how many watts is that inverter?  that appears to be 10 gauge wire not 4.  12 or 14 will work from the charge controller to the battery,  but if it was me I would use 10 gauge.  highdesertranger

The inverter is 450 watts.

 

[Trebor English]

If you put the inverter on the floor with the battery the wire length can be reduced to a few inches.  That will dramatically reduce the voltage drop in the wire from the battery to the inverter.  

If putting the inverter on the floor requires an extension cord it is better to run the longer wire on the 120 volt side as the current there, and the voltage drop, is one tenth of what it is on the 12 volt side.

 

[SoulRaven]

If you put the inverter on the floor with the battery the wire length can be reduced to a few inches.  That will dramatically reduce the voltage drop in the wire from the battery to the inverter.  

If putting the inverter on the floor requires an extension cord it is better to run the longer wire on the 120 volt side as the current there, and the voltage drop, is one tenth of what it is on the 12 volt side.

Good to know!

 

[tx2sturgis]

For about the same amount of money for the flexible solar panel, you could buy a 100 watt folding panel which would be much easier to carry along in the car.

If you plan on mounting the flexible panel on the roof, then disregard.

 

[SoulRaven]

For about the same amount of money for the flexible solar panel, you could buy a 100 watt folding panel which would be much easier to carry along in the car.

If you plan on mounting the flexible panel on the roof, then disregard.

I am choosing the flexible panel because of its light weight.  I'm not interested in lugging around 25lbs of carrying case.  It would be cool if someone would make a folding flexible panel. The long roll thing I saw in Bob's post is too long for my roof and I can't see trying to prop it up. Also I don't have the required hardware on the roof to mount a hard shell solar panel and adding a universal rack isn't an option for a naked 2012 Toyota Sienna.

 

[MrNoodly]

I went to Northern Arizona Wind & Sun for cables. I don't know the weight of the ones they gave me to go from the charge controller to the batteries, but they appear to be the same gauge as the cables from the panel to the controller. That makes sense to me since the controller would be passing along less power than is coming into it, not creating more power.

As for my inverter (a 400W Cobra) I used the cables that came with it, which also look to be the same gauge as the others.

However, my two batteries are connected to each other with cables almost as thick as my fingers.