diy solar

diy solar

Newcomer NEEDS help! (Updated!)

Oak_Sandalfoot

? Everybody Loves the Sunshine ?
Joined
Mar 16, 2022
Messages
44
Location
SWFL
**********Updated 4/22/22**********
Greetings solar community,

I need help setting up my first PV system in my Schoolbus RV conversion. I have the following components:

* PV array (3 x 250w in parallel)
-max VoC: 50.9, Isc: 6.2A (Sunpower)
*2500w PSWI (Reliable)
*100/50A MPPT SCC (Vic.)
*18A DC to DC charger (Vic. Orion)
*Lynx Power In busbar (modded to be a Fuse holder as well) (Vic.)
*412ah LiFePO⁴ battery bank (2 x 206ah wired in parallel) (SOK)
*DC fuse block and AC breaker box. (DC: 100a Blue Seas, AC box: N/A)
*Master disconnect wired at positive output terminal of the Lynx
*Shunt (Renogy) for BM (Renogy) at negative output of Lynx
*Fuses:
-Inverter: 400a mega
-SCC: 60a mega
-Dc to DC charger: 60a (lynx), 50a terminal fuse (starter battery)
-DC fuse box: 100a mega fuse
-AC breaker box: N/A
-Lynx positive output cable to battery: ANL, Mega or T fuse?

I've been working countless hours to learn all of this stuff on the internet from rock bottom/scratch with ZERO prior electrical experience. With the vast amount of information, seemingly infinite variations of design, conflicting viewpoints, my 'noobability', and the inability to discuss the issues face to face with a knowledgeable human, the whole process has been very challenging. I am proud of how far I've progressed in the past two months from the drooling idiot at the solar warehouse to someone who can actually read through a solar forum and understand the language and glean information; however, I am not too proud to know that I still don't know sh*t and I need help!

When I dip my head into that huge barrel of questionable apples, these are a few that float to the surface:

1)Can the following devices (going into the Lynx Busbar/fuse block) all be wired with 6awg?
*Orion DC to DC 12v/18a
*50a scc
*DC fuse box (blue seas w/ blade fuses)
-100a, 150a max (I think)

2)Inverter to Lynx cable gauge? (Short run <2 feet)
*1/0, 2/0 or 4/0 awg?

3)Lynx to battery cable gauge? (Short run)

*1/0, 2/0, or 4/0

4) I have some insulated 6 awg in two different types: one is like 50 strands or more, and the other is exactly 7 strands. Which is preferable to my application? Basically, coarse or fine strand cable? (I already learned that solid is not recommended for mobile applications)

5) Orion DC to DC 18a charger:

*Can it be wired to either the starter battery or alternator, or does it have to wire to both (I'm confused because none of the many, many install videos on 'the Tube' ever wire directly to the alternator.)
I'm assuming, based on extensive thread surfing, that connecting to the starter battery in effect connects to the alternator as well?

6) Is it advisable to put a dual pole DC breaker between the solar panels and the SCC? If yes, then what Amperage breaker)

7) Can the Inverter and SCC be grounded on the DC fuse box instead of the chassis? (Grounding to chasis is viable option if not)

8) What fuse (???A) between main positive of Lynx bus and battery bank? ANL, Mega, T Fuse?

9) Any recommendations or comments on my setup just based on the components listed?

Thank you in advance to everyone who contributes their time, money, and energy to make these sorts of 'far-flung' endeavors possible for a noob like myself.

Cheers,

Oak Sandalfoot

IG: Dumpstarsdivingbus
(Skoolie build and Dumpster diving)16505785654863796390011159136961.jpg
 
Last edited:
I'm not sure if this is what you are looking for, but I just started researching solar panel stuff about 2 days ago. This guy's stuff appears to be good? YouTube
 
Being relatively new myself, I'm really not the one to consult on other newbies' solar projects. It's a blind leading the blind kinda situation. Therefore I highly recommend watching Will Prowse's 400w off grid beginner tutorial video. It'll get you familiar with the 'bare metal basics'. AFter that you can leap down the rabbit's hole.
Good luck, mate!
 
I checked out your post and seeing as you built your own batter pack, you probably know way more than me!
 
I checked out your post and seeing as you built your own batter pack, you probably know way more than me!
I haven't built it, but I do feel fairly comfortable doing so. I just want to make sure everything will work together well. I'm particularly interested to see if I would be wasting electricity using a charge controller that handles up to 520w 12v, when I have 750w of poly solar panels. I know the polys are inefficient but are they that inefficient? This is assuming perfect weather conditions.
 
Once I started reading about balancing cells, configuring bms, sourcing individual parts from AliExpress, building a compact enclosure... I was like 'peace!'. I'm glad to hear that you're up for the task b/c I hear it's very rewarding experience! Curious to see how your system develops!
 
Based on the rabbit hole I went down and crawled back out of, I think you have to completely drain the batteries (individual cells in your case) with an appliance and then charge them with a power supply (another piece of gear you might only use once or twice) so they are the exact same voltage. There's a million videos on this aka there is no lack of clear and demonstrable info out there. Best of luck!
 
I have the following components
It would help a lot if you made an attempt at a wiring diagram showing all of the components, wires, fuses, breakers, etc. Label the important specs of each item including wire sizes, amp rating of fuses and breakers, etc. Put a question mark next to any item you are not sure about. Do this as fancy or as simply as you want. Draw it on a piece of paper or make a fancy drawing in an appropriate piece of drawing software. Which works for you. Then post the picture. It will be easier for people to offer suggestions. In the end you'll have a full diagram that will help getting it all setup.
 
You also need to provide some important details about your equipment:

- Post the full specs of the solar panels (or post a link)
- Post more details about the solar charge controller. Which make and model exactly? Post a link.
- Which make and model inverter do you have? Post a link.
- You may have a DC fuse box but for AC you would have some sort of breaker box. Post details.
 
I do have a schematic that I drew on notebook paper (couldn't upload it due to some memory issue on my phone). Anyhow, I'm confident in how I've arranged and connected all the components through cross-referencing a bunch of this guy, Nate Yarborough's, diagrams as well as the user manuals for my components. But here it is (the lynx does not have the main pos and neg, or shunt and fuse drawn in yet.
 

Attachments

  • 16505782108394240390423275169047.jpg
    16505782108394240390423275169047.jpg
    108.8 KB · Views: 5
You also need to provide some important details about your equipment:

- Post the full specs of the solar panels (or post a link)
- Post more details about the solar charge controller. Which make and model exactly? Post a link.
- Which make and model inverter do you have? Post a link.
- You may have a DC fuse box but for AC you would have some sort of breaker box. Post details.
Updated
 
1)Can the following devices (going into the Lynx Busbar/fuse block) all be wired with 6awg?
*Orion DC to DC 12v/18a
*50a scc
*DC fuse box (blue seas w/ blade fuses)
-100a, 150a max (I think)

Refer to an ampacity chart and a cable run chart (distance round trip) to determine cable size with a 3% max voltage drop

Ampacity chart will tell you the minimum size you need for the current you expect to carry, cable length will tell you if you need to size up for preventing voltage drop on a distance run.

Once you determine your wire guage, you will determine an appropriate fuse size to protect that wire.

2)Inverter to Lynx cable gauge? (Short run <2 feet)
*1/0, 2/0 or 4/0 awg?

Great. The shorter the better. Need to know the inverter power specs to determine what size cables and fuses will be needed.

3)Lynx to battery cable gauge?

*1/0, 2/0, or 4/0

This will be determined by the total expected load/current you will draw from the battery for your entire system.

4) I have some insulated 6 awg in two different types: one is like 50 strands or more, and the other is exactly 7 strands. Which is preferable to my application? Basically, coarse or fine strand cable? (I already learned that solid is not recommended for mobile applications)
You'll probably be able to put this to use somewhere. Yes you want stranded cable. No solid copper wire.
5) Orion DC to DC 18a charger:
*Can it be wired to either the starter battery or alternator, or does it have to wire to both (I'm confused because none of the many, many install videos on 'the Tube' ever wire directly to the alternator.)
I'm assuming, based on extensive thread surfing, that connecting to the starter battery in effect connects to the alternator as well?

Chassis battery is connected to alternator, connect the dc-dc charger to the chassis battery for source, and the house battery for load.

6) Is it advisable to put a dual pole DC breaker between the solar panels and the SCC? If yes, then what Amperage breaker)
Yes. Size is dependent on the specs of your panels.
7) Can the Inverter and SCC be grounded on the DC fuse box instead of the chassis? (Grounding to chasis is viable option if not)

you want a single ground bar with one connection to the chassis. Ground all of your components, AC, and DC bus to that bar. Starting to get into the weeds here because there are different ways to do this depending on your components properties, how they're mounted, and how they're wired.

8) What fuse (???a) between main positive of Lynx bus and battery bank? ANL, Mega?
Class t for lifepo4 batteries.

9) Any recommendations or comments on my setup just based on the components listed?

start putting together a wiring diagram.

Thank you in advance to everyone who contributes their time, money, and energy to make these sorts of 'far-flung' endeavors possible for a noob like myself.

Cheers,

Oak Sandalfoot

IG: Dumpstarsdivingbus
(Skoolie build and Dumpster diving)
 
Back
Top