Wire sizes

[surapak]

Hello everyone,

Thanks for your time. I recently bought a 100 watt solar panel to use for powering a dehydrator and also function as an emergency generator. I then purchased a 12v 128ah VMAX battery along with a Whistler 1200 watt inverter (modified wave). I have been using Renogy's diagram (which I've attached) to hash out the sizes for my wire's and fuses and I could use some help.

Should I use 12 AWG leading to the battery and 4 AWG leading to the inverter? And I calculated >120 amp fuses for the wires leading to the battery and >280amps leading from the battery to the inverter. Does this make sense?

Thanks,
Jack

[Sunking]

First problem is your battery cannot support a 1200 watt inverter. That would require the battery to deliver up to 120 amps at full power. The battery is only capable of supplying up to around 16 to 20 amps or a 200 to 250 watts maximum. Secondly I assume that is a PWM controller and with a 100 watt panel will only supply 5.5 amps of charge current and at 5.5 amps can only support a 40 to 70 AH battery. It is going to cause you headaches. Based on your panel and controller type you can only support a 12 volt 40 to 70 AH battery with a 100 watt inverter. Based on your inverter you would need a 12 volt 900 AH battery and a 1200 watt solar panel. You are way off matching equipment.

For a 1200 watt inverter will require a minimum #4 AWG copper between the battery and inverter.

[surapak]

Battery

Thanks Sunking. I guess I was hoping to get larger components and be able to add on. I guess this was the wrong approach.

How do I salvage this? Can I still use the battery even though it's too large for the panel

And yes it is a 30amp PWM controller.

Thanks again,
Jack

First problem is your battery cannot support a 1200 watt inverter. That would require the battery to deliver up to 120 amps at full power. The battery is only capable of supplying up to around 16 to 20 amps or a 200 to 250 watts maximum. Secondly I assume that is a PWM controller and with a 100 watt panel will only supply 5.5 amps of charge current and at 5.5 amps can only support a 40 to 70 AH battery. It is going to cause you headaches. Based on your panel and controller type you can only support a 12 volt 40 to 70 AH battery with a 100 watt inverter. Based on your inverter you would need a 12 volt 900 AH battery and a 1200 watt solar panel. You are way off matching equipment.

For a 1200 watt inverter will require a minimum #4 AWG copper between the battery and inverter.

[SunEagle]

Thanks Sunking. I guess I was hoping to get larger components and be able to add on. I guess this was the wrong approach.

How do I salvage this? Can I still use the battery even though it's too large for the panel

And yes it is a 30amp PWM controller.

Thanks again,
Jack

You can also get 2 more of those 100 watt panels which would be enough to charge that 128Ah battery. But you will need to down size your inverter to 200watt maximum and keep an eye on the battery voltage because even with the smaller inverter you can drain that battery running a 200watt load for a few hours.