Solar Power and Battery wiring info

[landoboguy]

Im adding extra solar, batteries and controllers to my rig, and stumbled upon this.
Some decent info may help less inexperienced, and yes some of it is to sell his links (which we can avoid) , USA but info to be gleaned the way he has laid it out, and may help some members none the less.

Solar Wiring Diagrams: https://explorist.life/solarwiringdiagrams

This is my list/index of solar wiring diagrams and parts list. There are currently wiring diagrams and parts lists for nearly 20 different sizes of setups.


CALCULATORS



Power Audit: https://www.explorist.life/what-size-of-solar-system-is-needed-to-power-a-camper/

This power audit is 100% the best way to determine what size of system YOU will need for YOUR electrical demands. It's a fairly lengthy process, but since solar is such a huge investment; it's very important to know how much you need. This articles includes a downloadable spreadsheet that will help you out.



Wire sizing Calculator: https://www.explorist.life/wire-sizing-calculator/



This is a simple calculator that will tell you what size of wire to use for various applications based on the amps of the device, the length of the wire, and the voltage of the source. I, personally, have this one bookmarked on the home screen of my phone I use it so much. If you want to learn more about 'how' and 'why' this calculator works, I have a video here explaining it: https://www.youtube.com/watch?v=ki3WXVR48eM



Alternator Charging Calculator: https://www.explorist.life/alternator-charging-calculator/



If you are planning on charging your house battery bank from your engine's alternator, this calculator will help you decide if you should use an Isolator or a B2B charger and which one (size) in particular, would suit your needs the best.



Solar Charge Controller Calculator: https://www.explorist.life/solar-charge-controller-calculator/



This calculator will help you choose the proper size of charge controller based on the size and number of solar panels in your solar panel array. If you want to learn more about how/why this calculator works, I've got a video here for you: https://youtu.be/MxziHKvTRh8




OTHER RESOURCES



Solar Panels - Series vs Parallel: https://www.explorist.life/solar-panels-series-vs-parallel/

This articles explains why I recommend wiring your solar panels in series for 95% of applications.



How to Wire 12v Lights & Switches: https://www.explorist.life/how-to-wire-12v-lights-switches-2-way-switches-in-a-camper/



This article explains how to wire switches (including 2 way switches) into your 12v accessory circuits that need switches (lights).



AGM vs Lithium Battery Bank: https://www.explorist.life/choosing-a-solar-battery-bank-for-a-camper/

This articles talks about choosing a Lithium battery bank over an AGM battery bank, the financial concerns of this decision, and why buying Lithium is the cheaper long-term choice.

Truck Camper Solar Install: https://youtu.be/Ht1kl37pJ2E



This was a start to finish install of adding a Inverter, charge controller, and solar panels in a Truck Camper with an existing electrical system.

 

[Ed on Toast]

Sounds like a wealth of invaluable information.

I am looking at solar, MBV etc for my new toy and finding the simple things quite daunting. So i will follow this thread with great interest.

 

[Ed on Toast]

I guess my biggest problem (percieved) is how to attach all the end connectors on the heavy duty cables.

Do i need to go out and spend a fortune on tools, i will use just once.

 

[Nabsim]

I guess my biggest problem (percieved) is how to attach all the end connectors on the heavy duty cables.

Do i need to go out and spend a fortune on tools, i will use just once.

No, you can get a set of crimps on eBay cheap enough. Probably looking at one for 8mm ring terminals

edit: that’s if you can’t borrow a pair, I wouldn’t get them made up unless you find somewhere who does it as part of the service. You can pay a lot more for custom cables some places

 

[Chris356]

Vehicle wiring products you pay per metre for cable plus eyelets then 50p per crimp they even heat shrink the joint it saves paying £80 for crimps

 

[Okta]

I find the cable size calculator half way down this page very useful.

Cable Size Calculator - Cable sizing and selection | 12 Volt Planet

Cable Size Calculator - Read our guide to selecting cable of the correct type and size for your automotive, marine or leisure wiring application. Auto and Marine Electrical Components from 12 Volt Planet

www.12voltplanet.co.uk

 

[trevskoda]

My advice is keep things simple and sep units,two panels 100w each ,heavy wire 3/4 mil down through roof in a marine gland,regulater mppt split as main to charge les batterys and 1ah line to charge starter bat,fuse both in from panel and at battery output.Some usb sockets and voltage readout which will keep you on track,dont spend lots on fancy stuff or you will end up a battery watcher.
About £350 will get you on target.

 

[Markd]

I guess my biggest problem (percieved) is how to attach all the end connectors on the heavy duty cables.

Do i need to go out and spend a fortune on tools, i will use just once.

It's worth considering soldering terminals on heavy (10mm2 and up) and then heat shrink sleeve over them.
You will need a small gas torch- I use the "kitchen" size refillable.
Hairdryer should do heat shrink (may need to restrict air flow slightly) if you don't have heat gun.

 

[Okta]

Some consider crimps to be more reliable and longer lasting than solder. I looked at various competing claims on the subject and decided to crimp.

 

[Markd]

I accept the stress fracture argument against soldering and guess that if you have a good crimp tool for larger cables it would be quick and easy - but they are not cheap.
Most commercial leads are of course crimped as they can generate enough pressure to "weld" the cable strands and the terminal together.

 

[trevskoda]

Mine were joined up in sealed boxes with screw connectors under panels and sealed with silicone,no more breaks until joined at regulator.

 

[Ed on Toast]

Right, i am of a mind, after reading all your sound advice here, to invest in a Victron BMV 712 and install it first.

Then see what this can tell me about my current system and what maybe needs to be looked at or upgraded.

I want solar, i have an awesome solar system on my campervan and really would like to end up with much the same but maybe bigger capasity on the boat. (It has no issue with space or extra weight)

The batteries seem to charge to 12.7 v but have fallen back to 12.4 v by morning, with only a couple of lights and a mobile on charge. So i am interested to do 'something' with the battery bank.

Solar panels are a definite but no massive urgency in the present overcast season.

I do have a suitcase generator, these are common place and socially acceptable on the marina.

So, i am thinking the Victron BMV 712 is a good way, for a novice to gain a better picture of my currwnt system strengths and weaknesses.

Am i thinking the right way or not?

 

[trevskoda]

My batteries got to 14.4 on the last good day of sun even though it was low in the sky.

 

[Markd]

One of the biggest downers on solar charging (any charging really) is old tired batteries.
There are those who say that they are the most likely cause of traditional mains charger problems drawing too much current for too long.
For solar reduced charge efficiency really eats into the harvest available.
Dropping 0.3v overnight does rather suggest they may not be all they might be?
Edit - The Victron device should help help by comparing harvest, consumption and storage.

 

[Nabsim]

Yes, it is better to get a good picture of what you actually use as a guide to how to charge it

 

[exwindsurfer]

I guess my biggest problem (percieved) is how to attach all the end connectors on the heavy duty cables.

Do i need to go out and spend a fortune on tools, i will use just once.

I’ve a crimping tool if you want to borrow it Ed it will do cables for 6mm to 70 mm

 

[Ed on Toast]

Thanks, Jeff

Has anyone had any dealings with Renogy, regarding solar etc..

AGM or Carbon Gels for leisure batteries?

and are Banner still the best for batteries for Wildcampers.

Thanks for all this advice, btw

 

[Markd]

AGM aren't great for sustained high current use in either discharge or charge. Carbon are a fancy AGM battery.
You may well find that Enhanced Flooded Batteries by Varta or Bosch perform better and last longer.

I'm taking a risk here because there are innumerable threads on "best battery"

Higher cost does not necessarily mean longer life and better performance -Read widely before you decide is all I'll say.

 

[Ed on Toast]

Interesting Mark,

So, what about the safe % discharge on such a battery?

 

[Markd]

I'm afraid that I can't comment on technicalities - others may offer answers or opinions.