No. of Solar Panels.

Discussion about any electrical topic except 240 volts. Solar, converters, inverters, lights, battery chargers, etc
User avatar
Craig
Posts: 774
Joined: Fri Dec 14, 2012 9:28 pm
Location: on the east coast.

Re: No. of Solar Panels.

Post by Craig »

T1 Terry wrote:Hi Shonky,
From your 270w of solar you should be getting around 15 amps in good sun, so something is wrong. Are the panels wired seperately with a run all the way down to the controller? You could try disconnecting one panel at a time to see if one panel isn't working. I'm guessing your Morningstar regulator is a PWM type and not an MPPT type as you plan to run the portable panel back to the controller.
I have 4 x 100w folding panels I connect to a 10 mtr length of 6B&S cable, Anderson plugs each end, an adapter plug consisting of 4 lengths of 6mm auto cable in each 50 amp Anderson plug terminal with MC4 connectors on the open end so the leads from the portables can plug straight in. The Anderson plug on the towbar is wired to the house battery charging system. It works very well when we stop long enough during the sunlight hrs to put the panels out, but i really need to put panels on the roof as well so they can be charging while I drive or when we are parked up sight seeing or shopping.

270 watts plus the third 140 watt panel
Full time on the road in an Alpine 2855
User avatar
T1 Terry
Posts: 15965
Joined: Fri Nov 23, 2012 3:44 pm
Location: Mannum South Australia by the beautiful Murray River
Has thanked: 50 times
Been thanked: 30 times

Re: No. of Solar Panels.

Post by T1 Terry »

I thought that was the third portable panel so not always connected... maybe I read it wrong :?
A person may fail many times, they only become a failure when they blame someone else John Burrows
Those who struggle to become a leader, rarely know a clear direction forward for anyone but themselves
User avatar
Craig
Posts: 774
Joined: Fri Dec 14, 2012 9:28 pm
Location: on the east coast.

Re: No. of Solar Panels.

Post by Craig »

Maybe you are correct as Shonky says he set it up resting against the bumper.
Last edited by Craig on Wed Jun 12, 2013 11:10 am, edited 1 time in total.
Full time on the road in an Alpine 2855
User avatar
shonky
Posts: 636
Joined: Tue Dec 25, 2012 10:31 am

Re: No. of Solar Panels.

Post by shonky »

Hi, all.

The third panel was loose and rested on the bumber temporarily, and is now fixed on the roof. The folder arrives this week.
See you on the back roads,
shonky et al.
User avatar
Craig
Posts: 774
Joined: Fri Dec 14, 2012 9:28 pm
Location: on the east coast.

Re: No. of Solar Panels.

Post by Craig »

Shonky, have you done any calculations on your daily power use?
Full time on the road in an Alpine 2855
User avatar
shonky
Posts: 636
Joined: Tue Dec 25, 2012 10:31 am

Re: No. of Solar Panels.

Post by shonky »

Hi, all.

Craig - yes, daily. The 12v Dometic 90l fridge draws 3.5amps, the big apple aka the Imac 21.5 draws 6amps and is normally on three to four hours each evening - we have a HUGE ebook, tv and movie library - and the 21 inch tv is rarely on but uses 3amps (I think) Gas stove and gas HWS. Lighting is around 1.5amp. The bus is a 2006 7m ex-rental Talvor, Queensland's answer to Australia's Wannabegone.

Usage is not the problem - the bus was in the driveway for six weeks late last year and the fridge never faltered, even when the bus was acting as a men's shed for most of that time. If the sun is too low fixed horizontal panels don't work.
See you on the back roads,
shonky et al.
User avatar
Craig
Posts: 774
Joined: Fri Dec 14, 2012 9:28 pm
Location: on the east coast.

Re: No. of Solar Panels.

Post by Craig »

If you are in Tassie you might have a problem with your fixed panels. As I said earlier I have the same amount of solar and have never had a problem with not having enough power coming in. The slowest days usually sees us full by mid afternoon. My point of asking about your usage had more to do with comparing the amount of solar input you have. So I have this clear in my mind, can you confirm that the fridge is a 3 way fridge? I thought that the 90 ltr fridges were all 3 way fridges (12v, 240v, and lpg). So would you think your total power consumption per day would be 120 ah?
Full time on the road in an Alpine 2855
User avatar
shonky
Posts: 636
Joined: Tue Dec 25, 2012 10:31 am

Re: No. of Solar Panels.

Post by shonky »

Hi, all.

Errata in previous posts- should have typed 6B&S cable, not 6mm.

No comments on reef knots and Rescue Tape instead of soldering or MP4 connectors? Hope the readers are in silent agreement not equally silent disgust.. The nice salesman at the camping show states that one turn of this tape will insulate 8000volts if applied correctly.

Craig - the fridge is 12v, not three way, and has a new exhaust fan, new 6B&S cabling straight to the battery, and i just fitted a large intake vent to it, all of which made no difference atall.
The fridge uses daily 3.5x24 = 84amps
The Imac uses 6x4 =24amps
Lighting about 4amps
equals 116 amps on a big day.
In good sun we should obtain 22amps from the roof panels,say for 6 hours max = 132amps, and in all seasons 8amps for 8 hours =64amps, from the folder, we hope. With some output from the roof panels this should give us between 64 and 200amps. Obviously we're more frugal with the computer's use and the fridge setting during inclement weather.
Craig, I know this is looking like a third battery is called for, but the point of my discussion is that folding panels have a definite use when the sun is not overhead. If you can gaze at the sun without tilting your head backwards fixed panels will not reach their maximum output.
See you on the back roads,
shonky et al.
User avatar
Craig
Posts: 774
Joined: Fri Dec 14, 2012 9:28 pm
Location: on the east coast.

Re: No. of Solar Panels.

Post by Craig »

I don't want to detract from the point of your discussion but I think you're having an issue with your panels that is not related to them being mounted flat on your roof. This is indicated by your previous post that states you only had 11.8 volts coming in. That would suggest that you had nothing coming in and the 11.8v was in fact the voltage in your batteries. Even if the sun is not directly overhead you should be getting more than 11.8 volts.

Craig
Full time on the road in an Alpine 2855
User avatar
shonky
Posts: 636
Joined: Tue Dec 25, 2012 10:31 am

Re: No. of Solar Panels.

Post by shonky »

Hi, all.

Craig - I concur that 11.8 was the battery voltage and as the day was overcast at 1400 there was nothing coming in. My point is reinforced by the excellent link I posted back on page 2 stating that ideally domestic solar arrays are fixed facing north at a considerable angle. My auto-sparkie checked my connections and all were fine - each panel showing over 20v on his multimeter and the Morningstar controller showing an input of 3v at 1545. The batteries were full at the time and I cannot recall the charging voltage.
See you on the back roads,
shonky et al.

Return to “Low Voltage Electrical”