Solar charging

[mudski]

Now this is getting wierd. I have been real busy with work and blowing the clutch up in my troll I didn't have time to post the panels back. So i get home a little earlier today, the sun was out, 27c outside, not a cloud in the sky and I though to sit outside with a beer, and package up the panel. But then I thought to give it one more shot with a 4AH 12V battery. To my surprise the charge light came on for the very first time since I purchased them, and it was charging at around 17Volts! Whereas before the charge light never came on and the highest reading I could get was around 3V.
Plus, whilst off the battery I checked the voltage output with my DMM and it was reading around 27Volts.!!!
So this regulator thats on it must auto switch or something. I was under the impression that this system I had will not work at all on a 12V battery...
I'm so confused now.

1. before it wasn't working now it is...
   And
2. The regulator I thought would only work with a 2 x 12V setup is working on a single 12V battery.

When I get back from holidays I'm gonna have to sit down and nut this out. Find out why it's now working, so then I am comfortable in selling it.
I have the Steca controller sitting on the shelf too...

[Cuppa]

http://www.exploroz.com/Vehicle/Electrics/Solar.aspx

I'll add this link here as I expect that it may be useful for anyone contemplating getting solar.

Disclaimer: It is written by a friend of mine, Collyn Rivers. He can be a cantakerous old so & so & I have disagreed on many things with him over the years, but when it comes to getting good information about fitting solar in easy to understand language he is the man.
When I first purchased one of his books, before I had met him, I was disappointed with how thin it seemed ( read the whole thing in a couple of hours), BUT as I went about my first solar installation (from a position of knowing nothing) I found I kept returning to it, & that it had ALL the info I needed. His skill is in being able to understand complexity & to then communicate this in a simplified manner acessible to all. For anyone considering outlaying good money on solar it is my belief that first buying one of his books is a good investment that will save you money & ensure that you end up with what you actually want. If nothing else it helps the buyer sort out the realities from the common myths that abound with solar, (& that all too often many sellers & armchair experts are willing to repeat).

Cuppa

[hempo]

mudski, what was the outcome?

[Robo]

If this helps, last summer I borrowed out laws Engel fridge and solar panel for a week+ away.
think 1.3 to 2.5amp power is the power figures for these Engels.

Took my 100amp-hr agm apollo battery 6 yrs old out of my car.
Connected to 40ltr engel fridge/freezer & set for fridge use only (but very cold), as we were far from town.
No other strain was placed on battery eg led lights etc.
Last night there, removed jaycar solar 120w fold panel at 5pm and packed it away going home next day.
The battery ran panel over night 5pm to 3pm next arvo, = 22hrs straight.
Put battery on charger when I got home that night still 80% charged.
Translates to approx 50% of acceptable drain in 22hrs use.

This yr I have a complete new setup of our own.
no more borrowing. Ha.
150w ebay panel,
150 amphr apollo agm deep cycle.
Ctek 20amp dc/dc mppt reg/charger (max input 300w ) fitted in van, connects via anderson at rear bumper.
And the wife's chrissy wish, a 50th anv Engel f/freezer, will be set as freezer only I think.
same fridge as before only much better controls and a gold paint job.
Van has 2 way fridge, gas /240v so will be used as fridge only.
This time will also be running a 5m led strip on van under awning, and interior leds.
oh also "backup only I hope" a 3000w continuous load pure sine gen.
As far as "noise" goes, I compare it to the 2000w eui honda at work.
Ebay gen $609 delivered verses honda $3900, easy choice for me.
See how we go.
PS gen also serves as power in blackout at home hence the size.
sorry for the hijack but
Maybe someone can confirm a 12v/240v inverter drain on 12 volt system power supply.
I read some where appliance watts x 10 equivalent on battery drain.
Eg-- 10amp appliance @240v = 100amp @ 12volts.
and how going large power inverter is waste on low drain appliance.
help out us free campers.

cheers.
And Merry Christmas Everyone.

[sooty_10]

http://www.exploroz.com/Vehicle/Electrics/Solar.aspx

I'll add this link here as I expect that it may be useful for anyone contemplating getting solar.

Disclaimer: It is written by a friend of mine, Collyn Rivers. He can be a cantakerous old so & so & I have disagreed on many things with him over the years, but when it comes to getting good information about fitting solar in easy to understand language he is the man.
When I first purchased one of his books, before I had met him, I was disappointed with how thin it seemed ( read the whole thing in a couple of hours), BUT as I went about my first solar installation (from a position of knowing nothing) I found I kept returning to it, & that it had ALL the info I needed. His skill is in being able to understand complexity & to then communicate this in a simplified manner acessible to all. For anyone considering outlaying good money on solar it is my belief that first buying one of his books is a good investment that will save you money & ensure that you end up with what you actually want. If nothing else it helps the buyer sort out the realities from the common myths that abound with solar, (& that all too often many sellers & armchair experts are willing to repeat).

Cuppa

I just had a good read of that article and a google of Collyn found a few more simple to understand articles by him.... thanks

[FNQGU]

He certainly is easy to understand. I now have his camper trailer book and it is a real goldmine of info.

[mudski]

Great article to read. The only thing I don't really agree on, but see where he's coming from is his comment about adding and extra battery. He says its a waste of money and that money should be spent in more panels. All good to say that if you know your going to have plenty of sunlight to make use of. If you experience three or four days of clouds and no sun, like many would have, the extra panels is useless and your foobar. Ideally having more of both is great but I would lean to an extra battery and have both well charged before I leave and also run the panels. Even though the panels won't be enough to charge both batteries, it will slow the discharge process I would think.
He also says "The maximum battery capacity must never exceed that which you can readily fully charge most days. Ideally have about 250 watts of solar per 100 Ah battery capacity."
I assume that would count nearly every camper out if they had two batteries. Well me anyway, I have 180W and one 100AH AGM in the camper, and looking into another. Seems I need to look into more panels...

[Robo]

Great article to read. The only thing I don't really agree on, but see where he's coming from is his comment about adding and extra battery. He says its a waste of money and that money should be spent in more panels. All good to say that if you know your going to have plenty of sunlight to make use of. If you experience three or four days of clouds and no sun, like many would have, the extra panels is useless and your foobar. Ideally having more of both is great but I would lean to an extra battery and have both well charged before I leave and also run the panels. Even though the panels won't be enough to charge both batteries, it will slow the discharge process I would think.
He also says "The maximum battery capacity must never exceed that which you can readily fully charge most days. Ideally have about 250 watts of solar per 100 Ah battery capacity."
I assume that would count nearly every camper out if they had two batteries. Well me anyway, I have 180W and one 100AH AGM in the camper, and looking into another. Seems I need to look into more panels...

I'm no expert and not preaching I'm learning here also.
I think he's allowing for any drain on solar input also whilst charging "something running" through the day.
the 120w panel I used regulator was pwm and the small drain was 50% allowable ( ideal ) drain in 22 hrs, if we had bad sunlight the previous day the batteies capacity would of suffered, and that's was for a small load requirement.
chewing it over I think he's on the money for what the "efficient" Engel drained last outing.
Tink he's also allowing for no over-discharge of battery capacity max drain 40% with 60% still in reserve, otherwise battery performance and longevity is at risk.
Humm, after reading artical I think I may need another panel to protect/prolong expensive agm bat.
Cheers,
And Merry Chrissy and Happy New Year Peoples.

[Robo]

update.
with mostly hot sunny days.
The 150 watt ebay panel kept the 150 amp-hr agm battery charged ok.
With 40 ltr Engel running at neg 9 deg no problem for 9 days straight.
solar Panel was put out around 10 am facing east and moved west after lunch & no other movement.
Few days panel only saw 5hrs light, sight seeing 4x4 etc
Tried a day, 24hrs use and not connecting the panel to test capacity drain on battery, geny & connecting 240v smart charger battery was down to 73% capacity.
this is around the desired max drain limit, to ensure battery longevity.
Engel was freezing milk and meat well, but as expected slower than home fridge.
I found if I went below -11 freezer was running to frequently.
-9 nice medium of run time for 35deg +days.
neg 6 wasn't freezing really to well "to slow to freeze" +35 ambient wasn't' helping.
didn't' really use led lights much out side or inside for that matter, recon if more use a 2nd panel was on the cards.

A Good Christmas and New year.
Hope you had the same.

[threedogs]

where is the Engel if in the Patrol? I would suggest either parking in the shade and running a lead to your Panel,
or darken the cargo area with either that silver foil sheet, or black perforated stick on.
Out of interest how many AH does the 150 panel produce on a sunny day.
You may have been better with two 80 Watt panels, I'll wait
Edit its 8.5 AH ,You might get 9AH running a twin 80 panel marginal