Solar Panels - Information and Questions

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Just got home Friday, 5 weeks in the GT, all off mains power. To recap - 2 x 100W SunPower panels, 1 x 130AH AGM, diesel heater, TV, lights etc. (Fridge on LPG). Av. TV was 4hrs a night. Av. heater 14hrs a day. Solar Controller is a 20A Victron MPPT.

First couple of weeks were sunny, average temp was 23-28C, but nights were mainly cold enough to require the heater. As it was not really cold the heater thermostat cuts off when not needed and resulted in an average of 30AH daily use. On a few occasions I was detecting near to camp, I came back for lunch at about 12.30pm and checked the battery monitor to note 100% charged.

The last 10 days or so was much more overcast daytime and colder at night, resulting in an average of 37-40AH daily use. Although I only returned to camp on 1 day during this time for lunch, I noted the battery at 86% charged, but except for 1 day it was at 100% by 5pm.

A few days ago during a constant rainy overcast day the battery was still at 89% at 5pm with only 0.8A charge going in, so the genny got used to top up.

So, size wise, 130AH battery @ 25% depth of cycle (DOC) is 32.5AH and my trip max of 40AH is 30% DOC, I'm happy that the battery is the right size for my use.
Also, that other than 1 day out of 35 away, my 200W panel sizing is charging as it should.

As I've mentioned before, if you are looking at setting up a solar system, the first thing to establish is what your daily power use is. So first purchase should be a battery monitor, preferably one that shows charge +A and load -A as well as V and battery state %. That will then tell you what size battery/s you need to maintain a healthy DOC and how much solar you need to replace it and subsequently controller size for panel total output.

BTW I also charged my mobile phone, WiFi modem, laptop (Jaycar 12VDC power supply), GPX battery, SDC 18650 and C cell, SP01 Amp, Deteknix wireless Tx and phones all from the van battery, every day. :)
 
I might add for those interested, that the charging of all the detector gear batteries, wireless and mobile phones use "bugger all" power AH wise. Although I've measured their requirements in the past, it's such a small % of my daily use, I don't worry about it.

So for those with minimal 12V systems or even car charging of same, it's really no problem.

The main criteria are; if its 5VDC USB charging get a plug in 12V USB converter, if it's 12VDC charging go straight to the battery. V all of the items I listed have 240VAC charging options, but to run an inverter to use them will cost many more times the battery AH to drive em :)
 
The companion solar panels at Bunnings are now out at $149.00. Picked the last one up at the Noarlunga store and have it set up next to my projecta 120 watt for a comparison. The project is slightly heavier and about 100mm taller. Both are charging a waeco 36amp hr battery each, both batteries were reading 12.6 volts, so it will be interesting to see how each performs. The projecta cost me $459 three years ago.
1557981853_image.jpg

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Top image companion, bottom projecta.

I don't have a multi meter or anything to measure with so just a side by side comparison.
 
Well it didn't take too long, both batteries are now full, so took about the same time. I even managed to fold the companion one up and get it back into its original box. For a $149 blanket it's pretty good value, easy to set up and use, only a PWM but that's all I need, I have a blanket for each battery, so power should not be an issue, Combined with 110amp/hr in the trailer giving a total of 180amp/hrs and 250w of solar to recharge and only runing a 50litre waeco and some led lights.
 
Hi folks with more brains than me. Is there a difference between 24 and 12 volt solar panels or is it all in the regulator?

I have solar panels from a 24 volt solar pump setup, will they work if used with a 12 volt regulator?

Many thanks.
 
Thank you Doug!
I think the panels are 240 watts or there abouts each. One will fit nicely on top of the Landy and one nicely on top of the van :Y:
 
Agree with Nightjar.
A reasonable 12V MPPT controller (viz: Projecta or RedArc) will handle an input voltage of around 32V.
Best to check the solar panel's open circuit (i.e.: no current draw) maximum voltage though, and get an MPPT that can handle it.
 
There will be a label on the back of the panel, if you can take a pic and post it.

Just read your second post, one on vehicle one on van.

Are the two panels to charge one battery or a battery in each?
 
Can be used for either if using a 12/24v controller just remember to hook up the controller to the battery first so it knows what voltage the system is and can charge accordingly.
 

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