My Build Questions - Camper Van 480W Solar 12V 200Ah LifePo4

[ianganderton]

Finally starting to install this system



Purchased Product Specifications

Battery – SunnyTech (badged Lithium Valley) 12V 200Ah Lifepo4
https://web.archive.org/web/20210130064931/https://sunnytech.co.nz/store/default/product-details/121/69/0/0

Solar Panels – SunnyTech 120W x 4
https://sunnytech.co.nz/store/default/product-details/22/66/0/0

Solar Charge Controller – Epever Tracer 4120AN
https://www.epever.com/product/tracer-an-10-40a-mppt-charge-controller/
Manual - https://www.epever.com/wp-content/uploads/2021/05/Tracer-AN-SMS-EL-V1.0.pdf

Inverter – Epever IP2000-12-Plus
https://www.epever.com/product/ipower-plus-220-230vac-pure-sine-wave-inverter/
Manual - https://www.epever.com/wp-content/uploads/2021/09/IPower-Plus-Manual-EN-V2.2.pdf

Bus Bar 4 x M8 https://www.aliexpress.com/item/1005003140776626.html?spm=a2g0o.9042311.0.0.30ab4c4dAm22VK

12V x 12 Fuse Box - https://www.aliexpress.com/item/1005002460212327.html?spm=a2g0o.9042311.0.0.30ab4c4dAm22VK

SCC & Inverter Remote Display - MT75
https://www.epever.com/product/accessories-mt75-remote-meter/

Data Logging - E-Log
https://www.epever.com/product/elog-01-logger/

 

[ianganderton]

My first questions are around fusing and breakers

I want to put a fuse on the battery as close as possible to the +ve terminal. I'm not quite sure what product to use to do this. Its an M8 stud terminal as seen in this image

 

[ianganderton]

Question 2 is around breakers and disconnects

What are:
a) the minimum requirements?

and

b) what is best practice?

 

[ianganderton]

OK so been researching solar disconnects.

Nate at ExploristLife has this blog post - https://www.explorist.life/how-to-wire-a-solar-disconnect-for-a-diy-camper-electrical-system/

This product available locally (New Zealand) looks a good option



Solar Disconnect - Suntree 32Amp Solar System DC Isolator - https://sunnytech.co.nz/store/default/product-details/105/73/82/0

UV Resistant IP66 Enclosure

Extremely Short Power Shut Off Time Of Approx.2ms

Lid Only Removable In "off" Position

Earth Terminal

Rated Voltage: 1000v DC

IP Rating: IP66

Connection type: MC4

Rated current: 32A

Standard: IEC60947-3,AS/NZS60947.3: 2015

 

[ianganderton]

Updated diagram

 

[Bvillebob]

So you're not going to have any provision for charging from your alternator?

 

[ianganderton]

So you're not going to have any provision for charging from your alternator?

not at the moment but it will be easy to add in if its needed

 

[ianganderton]

Fitted the solar panels today. I’m pretty pleased with how neatly they’ve gone on





480W fills the space available on the roof very neatly. Panels were about $95US purchased locally here in NZ

The plan has been to put as much solar watts as would fit in the space. It will be interesting to see if it keeps up with needs during the winter and removes the need for alternator batter charging.

 

[Browneye]

Like.
Subscribed...

You have a BlueSea master switch in there...and fuses indicated. You need to fuse/break your SCC, and one to your inverter. For the former I like a switching breaker, the latter an ANL fuse block.

Junctek meter? Some will laugh. I have one, love it. ?

An alternate PV cut off is a mini-din double breaker in a weatherproof box, like this. Just make sure it's DC rated:

 

[Rickey]

I know Junctek BMS, about it, you can consult me, I am happy to answer.

 

[12VoltInstalls]

pretty pleased with how neatly they’ve gone on

You should be. They look nothing like some of the crazy white-knuckled-monkey installations some people do.
Nice job

 

[ianganderton]

OK, muchos procrastination!! I just havent been happy with the system plan, it was feeling overly complicated with waaaaayyyy to many connections and joints. A small part of my procrastination is available to view over on HERE

But I think I'm getting there. This is where I'm up to



This post is going to be a pretty big information dump. I've still got some cable sizing to do but I think I have a plan

Key to this design is the Victron Lynx Power In with DIY fuse adaption that makes it pretty cost effective, neat, compact and robustly reliable. My plan is to connect both the battery disconnect and the juntek shunt to the Lynx using a pair of Blue Sea Link Buses that I have.



In the post I've linked to at the start @John Frum pointed out the high Amps the system would potentially need to deal with when the inverter is working hard and the battery voltage dropped with low charge. I've found the solution to that in the inverter manual! who would have thought it!! Reading the manual, crazy times.

Anyway the low voltage disconnect is user configurable! Screen snip of the manual

Then looking at the battery data sheet

If I set the low voltage disconnect to something like 12.3V that will protect everything against high amps caused by low battery volts and current draw (1C, 200A). Not sure what to set the reconnect at yet

2000W + 15% inverter inefficiency = 2300W

2300W / 12.3V = 187A which gives me 25% headroom

I think my maths is correct

So here are the details of the various components so far

Battery – SunnyTech (badged Lithium Valley) 12V 200Ah Lifepo4 https://web.archive.org/web/20210130064931/https://sunnytech.co.nz/store/default/product-details/121/69/0/0
(I'll attach the specifications and data sheet from this archived weblink)



Solar Panels – SunnyTech 120W x 4 https://sunnytech.co.nz/store/default/product-details/22/66/0/0


Solar Charge Controller – Epever Tracer 4120AN https://www.epever.com/product/tracer-an-10-40a-mppt-charge-controller/
Manual - https://www.epever.com/wp-content/uploads/2021/05/Tracer-AN-SMS-EL-V1.0.pdf

Inverter – Epever IP2000-12-Plus https://www.epever.com/product/ipower-plus-220-230vac-pure-sine-wave-inverter/
Manual - https://www.epever.com/wp-content/uploads/2021/09/IPower-Plus-Manual-EN-V2.2.pdf

Blue Sea MRBF Terminal Fuse Block https://www.lusty-blundell.co.nz/pr...al-fuse-block/category/1579-fuses-fuse-blocks



12 Fuse Box - https://www.aliexpress.com/item/1005002460212327.html?spm=a2g0o.9042311.0.0.30ab4c4dAm22VK

SCC & Inverter Remote Display - MT75 https://www.epever.com/product/accessories-mt75-remote-meter/

Data Logging - E-Log https://www.epever.com/product/elog-01-logger/

Solar Disconnect - Suntree 32Amp Solar System DC Isolator - https://sunnytech.co.nz/store/default/product-details/105/73/82/0
(Not sure about this, think I'm going to return it and use DC breakers instead)

Junktek Battery Monitor KG140F https://www.aliexpress.com/item/1005003245578434.html?


Because of the Lynx Power In there is easy room for adding both a DC2DC charger from the alternator and a mains charger too

 

[ianganderton]

Cable & Fuse Sizing

All cables are pretty short with components placed as close as sensible to each other while allowing for operation and correct air circulation. Calculations are done on 1m

Solar Panels to SSC - 6mm2 no fuse just disconnect

SSC to Lynx - 16mm2 AAAAAHHHHHHH mega fuses needed in the Lynx dont seem to come small enough, need something for 50A

SSC to 12V fuse box - 16mm2 - my assumption here is the battery and load terminals are the same circuit so protected by the Lynx fuse

Battery to Lynx 70mm2 with 250A terminal fuse

Lynx to Inverter 70mm2 with 250A mega fuse

 

[ianganderton]

So the 40 to 50A mega fuse conundrum.

Google pulled up thus post

48 v 40 amp mega fuse?

hi everyone. I’m stuck. I can’t find any fuses with small enough amperage to work with my victron 150/35 mppt and the lynx distributor. The wire size I’m using was 10mm going out. I thought a 40 or 45 mega fuse would do. Can’t get one for 48v system.......So I’m looking to use the max wire that...

diysolarforum.com

rmaddy said:
The Blue Sea Systems wire/fuse chart shows that a single, unbundled, 105ºC 6AWG wire (a bit smaller than 16mm²) can handle up to 125A. Therefore a high quality 16mm² wire can handle more than 125A. So as long as your 100A fuse is rated for 48V then you should be good.

Any thoughts?

 

[ianganderton]

Updated diagram

 

[Pi Curio]

Updated diagram

View attachment 107752

What's the name of the program you're using to draw this diagram? Simple to use?

Appreciated.

 

[ianganderton]

What's the name of the program you're using to draw this diagram? Simple to use?

Appreciated.

Its just Microsoft Word and I take a screen snip (shift/windows key/S) to get the image then paste it into the forum

 

[Pi Curio]

Its just Microsoft Word and I take a screen snip (shift/windows key/S) to get the image then paste it into the forum

View attachment 107753

That's creative, looks very organized. I was convinced it was some software for drawing a solar system diagram.

Very nice.

 

[ianganderton]

Solar irradiance data for New Zealand cities taken from http://www.solarelectricityhandbook.com/solar-irradiance.html

 

[Browneye]

All loads off the charge controller? You need your feed directly off the battery or lynx,