Newbie help! Advice for planned setup

[IcarusFF]

Hi everyone,

This is my first attempt at a DIY portable solar system. Im starting small and basic, dont need to run a lot on it and I dont plan to be offgrid for more than a few days at a time.

- Not using a vehicle to charge the system, only solar input
- This is my current planned build so far (please excuse the rough sketch). My biggest head scratching points so far have been with the wiring and breakers.
- I also got a battery box but im now unsure if using this will be easier, or if wiring it up manually will be easier. I purchased with the idea of using anderson plugs for the entire portable setup but a lot of MPPT devices dont come prewired with anderson plugs... PLUS where would the breakers go if i did this?
- How badly do i need breakers for a setup this size at all?
- Im also not having much luck finding the items with the orange diamond, but everything else I have sourced

Any advice much appreciated! Any changes I need to make?
I dont really mind if it's not the best, I just dont want anything to set on fire haha.

Solar blanket: https://tinyurl.com/fjwrj8bv
MPPT: https://www.australiandirect.com.au/buy/kickass-mppt-solar-controller-40a/KA1224MPPT40A
Lithium Battery: https://outbax.com.au/voltx-12v-100...y-lifepo4-deep-cycle-recycle-camping-rv-solar
Converter: https://www.edisons.com.au/genpower...verter-caravan-boat-carplug/?___store=default
Battery box: https://tinyurl.com/yzy5akt5
Breaker: https://offroadliving.com.au/products/circuit-breakers?variant=30607276441718

 

[chrisski]

For the battery to SCC breaker, you won’t need a 50 amp breaker for a single 200 watt panel, the short circuit current is only 20 amps.

Also, because the max current from the SCC will not require 4 AWG. Unfortunately the PWM power is not listed, but 20 amps at 18 volts will convert to around 30 amps. If the run is extremely long, 4 AWG maybe required, but not for a normal run.

For the Anderson plugs, I’m not sure which ones they are, there’s many types, but this grey Anderson plug on Amazon is 50 amps for 6 gauge wire

Amazon.com: 5 Pairs (10Pcs) 50 Amps 600V Connector Kit, Gray for Anderson powerpole: Home Audio & Theater

Amazon.com: 5 Pairs (10Pcs) 50 Amps 600V Connector Kit, Gray for Anderson powerpole: Home Audio & Theater

www.amazon.com

THere are also higher amperage Anderson Plugs of different types that will fit those wires. Those could be the correct plugs.

I like to see something like a part number or amperage of the plug before I order.

For the open wire, if its indoors I use THHN, and if its outdoors and exposed to sun I use PV wire which where I shop is available to 8 AWG. The wire I mentioned is rated for other things, but is good for the use I mentioned.

Wire & Cable Your Way: Electrical Wire By the Foot

We are a trusted online distributor of electrical wire and cable products, offering fast shipping on a huge selection of SKUs, cut-by-the-foot or in bulk.

www.wireandcableyourway.com

Breakers protect wires, so I don’t recommend exceeding the ampacity of the wire. If 150 amp breaker is important for your choice than 1 Gauge or 1/0 wire. If 4 AWG is important, than less than a 100 amp breaker. If you have specs for your wire that are rated higher, than you may be able to use that.

 

[IcarusFF]

For the battery to SCC breaker, you won’t need a 50 amp breaker for a single 200 watt panel, the short circuit current is only 20 amps.

Also, because the max current from the SCC will not require 4 AWG. Unfortunately the PWM power is not listed, but 20 amps at 18 volts will convert to around 30 amps. If the run is extremely long, 4 AWG maybe required, but not for a normal run.

For the Anderson plugs, I’m not sure which ones they are, there’s many types, but this grey Anderson plug on Amazon is 50 amps for 6 gauge wire

Amazon.com: 5 Pairs (10Pcs) 50 Amps 600V Connector Kit, Gray for Anderson powerpole: Home Audio & Theater

Amazon.com: 5 Pairs (10Pcs) 50 Amps 600V Connector Kit, Gray for Anderson powerpole: Home Audio & Theater

www.amazon.com

THere are also higher amperage Anderson Plugs of different types that will fit those wires. Those could be the correct plugs.

I like to see something like a part number or amperage of the plug before I order.

For the open wire, if its indoors I use THHN, and if its outdoors and exposed to sun I use PV wire which where I shop is available to 8 AWG. The wire I mentioned is rated for other things, but is good for the use I mentioned.

Wire & Cable Your Way: Electrical Wire By the Foot

We are a trusted online distributor of electrical wire and cable products, offering fast shipping on a huge selection of SKUs, cut-by-the-foot or in bulk.

www.wireandcableyourway.com

Breakers protect wires, so I don’t recommend exceeding the ampacity of the wire. If 150 amp breaker is important for your choice than 1 Gauge or 1/0 wire. If 4 AWG is important, than less than a 100 amp breaker. If you have specs for your wire that are rated higher, than you may be able to use that.

View attachment 58156

Thank you so much for your reply!

So just to get this straight...

- Use wire rated for 30amps between [solar panel -> MPPT] and [MPPT -> battery]. So 10AWG ? Could I use 8AWG ?
- Should i downsize my MPPT to a 30amp instead, in that case?
- For the breaker between the [MPPT and battery], do I use one rated at 30amps or give it some head room and use a 40amps breaker?
10AWG wire - 30amp breaker?
8AWG wire - 40amp breaker?

- For the breaker between the [Battery -> Converter] im using the 4AWG wire? and so a breaker rated at 100amps would be suitable here?

 

[chrisski]

- Use wire rated for 30amps between [solar panel -> MPPT] and [MPPT -> battery]. So 10AWG ? Could I use 8AWG ?

Panels in series probably don’t need wire greater than 10 AWG. Going through the roof is a pain so 6awg could be good for future expansion. You could put the panels in parallel with 10 AWG to a combiner box. This will probably give you about 20 amps from each panel with 10 AWG and once combined on the roof 20 amps

- Should i downsize my MPPT to a 30amp instead, in that case?

If cost is not a factor I say no. That way as you add on panels later, you won’t need a bigger SCC.

- For the breaker between the [MPPT and battery], do I use one rated at 30amps or give it some head room and use a 40amps breaker?
10AWG wire - 30amp breaker?
8AWG wire - 40amp breaker?

I’m going to recommend the sites resources section. There is a current interupt (Fuse/circuit breaker) formula. Something like expected amps *1.56 but don’t exceed wire ampacity.

- For the breaker between the [Battery -> Converter] im using the 4AWG wire? and so a breaker rated at 100amps would be suitable here?

The wire has ampacity, but find a dc voltage loss calculator and figure the voltage loss. I stick to 3% or less. If your not going from one end of the trailer to the other you should be fine, but part of the process is the math.