Wiring Question

[mattb89]

This is my first post on here so hopefully I can get some good information... So the solar project I want to do is use a single panel to power a 12v 5amp water pump. I've brought the water pump from harbor freight (http://www.harborfreight.com/12-volt...ump-94639.html) and it uses 14 AWG. I want to add a on/off switch to it before it gets to the controller (http://www.amazon.com/gp/product/B00...=A867P1BBKCZM8). I'll use 14 AWG to go from the battery to the controller. But my question is, does the gauge of the wire from the solar panel to the controller matter?? I'm thinking of just buying this panel which comes with it's own wires (http://www.amazon.com/gp/product/B00...A18M12GR6V2Z8F).

Thanks for any help with this.

[SunEagle]

This is my first post on here so hopefully I can get some good information... So the solar project I want to do is use a single panel to power a 12v 5amp water pump. I've brought the water pump from harbor freight (http://www.harborfreight.com/12-volt...ump-94639.html) and it uses 14 AWG. I want to add a on/off switch to it before it gets to the controller (http://www.amazon.com/gp/product/B00...=A867P1BBKCZM8). I'll use 14 AWG to go from the battery to the controller. But my question is, does the gauge of the wire from the solar panel to the controller matter?? I'm thinking of just buying this panel which comes with it's own wires (http://www.amazon.com/gp/product/B00...A18M12GR6V2Z8F).

Thanks for any help with this.

Hello Matt and welcome to Solar Panel Talk

First off that pump shows a rating of 50watts so depending on how long you are going to use it will determine your battery size. From there you can determine how many watts your pv panel needs to be as well as your charge controller amp rating.

Wire size is based on the amount of amps it will carry as well as how far between components. So you need to know the distance between the panel and charger, charger and battery, battery and pump. Only then can you size your wires to stay within a 2% voltage drop.

That solar panel with its own wires at 5watts will be way too small to run your pump or recharge your battery.

[mattb89]

Hello Matt and welcome to Solar Panel Talk

First off that pump shows a rating of 50watts so depending on how long you are going to use it will determine your battery size. From there you can determine how many watts your pv panel needs to be as well as your charge controller amp rating.

Wire size is based on the amount of amps it will carry as well as how far between components. So you need to know the distance between the panel and charger, charger and battery, battery and pump. Only then can you size your wires to stay within a 2% voltage drop.

That solar panel with its own wires at 5watts will be way too small to run your pump or recharge your battery.

I already bought a 12v 20ah battery and the distance from the panel to the charger shouldn't be more than 6ft. I'll run the pump for about 30 mins just to water a garden every other day. Thanks for your response.

[SunEagle]

I already bought a 12v 20ah battery and the distance from the panel to the charger shouldn't be more than 6ft. I'll run the pump for about 30 mins just to water a garden every other day. Thanks for your response.

Ok. That 20Ah battery should be big enough to run that pump for 30 minutes a day. And that charge controller can handle up to 10 amps. So my suggestion is to get a 40 watt panel with an Imp rating ~ 2.2amps. That should provide you enough charging capacity. If you go with a smaller panel you will not have enough charging amps to keep that 20Ah battery happy.

You would want to keep distance between the battery and pump to less than 10 feet but to be safe I would go with a #12 AWG wire instead of the #14. I would use the same #12 wire between the panel and charge controller as well as between the CC and battery.