Critique my setup

[BlueMarblePA]

1120 watts of used panels in 2S2P (72v/16amps) to a solar disconnect then to a victron blue solar 100/30 for a 24v battery system

(I know that 1120/24=46 amps, but I have used panels and expect poor sunshine on my shed as it only gets sun from 9am to 1:30pm)

Mppt goes to the red and black bus bar.

From 2x12v batteries wired in series, I have the black negative going to the victron smart shunt which then goes back to the black bus bar.

From the positive side of the battery bank, I have a blue seas 100amp terminal block fuse going to a red switch to shut down the circuit which then goes to the red bus bar.

From the red and black bus bar, I then go into the Cotek 24v 1500 watt sine wave inverter. The chassis ground will go to 8 foot copper rod next to shed (two of them separated by eight feet and connected with 6 gauge bare copper)

Solar panel racks will be connected to same ground with weeb connectors and to the same ground rod that the inverter goes to


Cotek is 1500W inverter with a 91% efficiency/24V = 68.7 Amps. However, you want to add a 25% insurance factor, so 68.7*1.25 = 85 (Let's round to 100 Amps)

Using this calculator http://circuitwizard.bluesea.com/
24V, 75 Amps, 10 feet round trip from battery to inverter. It says I can use 6 AWG. I chose to use 4AWG.

 

[OffGrid Cabin MO]

what's a bus bar? sorry for noob question

 

[PreppenWolf]

what's a bus bar? sorry for noob question

A busbar is a common point to connect cables.

 

[BlueMarblePA]

 

[MichaelK]

1120 watts of used panels in 2S2P (72v/16amps) to a solar disconnect then to a victron blue solar 100/30 for a 24v battery system

(I know that 1120/24=46 amps, but I have used panels and expect poor sunshine on my shed as it only gets sun from 9am to 1:30pm)

Be more careful here. Used panels I bought have outperformed new, retail-purchased panels tested side by side. Assume your batteries will start charging at 25V. With 85% derating, I think what you would actually see is.... (1120W/25Vcharging) X 85% = 38A. The 30 amp controller would let you waste about 20% of the power in your peak period.

From 2x12v batteries wired in series, I have the black negative going to the victron smart shunt which then goes back to the black bus bar.

How big are those batteries? They look well-insulated, so I'm assuming they're Li? I'd say using a C/4 charging rate, your 38A would be adequate to keep a 150Ah battery bank charged.

24V, 75 Amps, 10 feet round trip from battery to inverter. It says I can use 6 AWG. I chose to use 4AWG.

I would consider 4 gauge bare minimum. I have 000 on my 24V inverter.

 

[sunshine_eggo]

A busbar is a common point to connect cables.

View attachment 123723

I have a set from Pike. Good stuff. Also great Victron support.

 

[BlueMarblePA]

Be more careful here. Used panels I bought have outperformed new, retail-purchased panels tested side by side. Assume your batteries will start charging at 25V. With 85% derating, I think what you would actually see is.... (1120W/25Vcharging) X 85% = 38A. The 30 amp controller would let you waste about 20% of the power in your peak period.


How big are those batteries? They look well-insulated, so I'm assuming they're Li? I'd say using a C/4 charging rate, your 38A would be adequate to keep a 150Ah battery bank charged.

I would consider 4 gauge bare minimum. I have 000 on my 24V inverter.

I have 2 x 12 v 100Ah battleborn heated batteries. I currently do not have any significant load connected. My plan is to run a pool vacuum cleaner in the summer. I need to learn more about C/4 charging rate.

I remember @willprowse saying that you will end up upsizing everything as time goes on, so it is better to start with large awg wire 4 AWG is barely enough, but we will see what happens in the future.