i am sure somewhere in the archives this has been spoken about,,,, when my van is at home i have a 110amp panel on my carport connected by prewired anderson plug which goes to my 20 amp mppt controller ,this maintains my house battery ,as long as i dont use anything in the van too much, now as regular readers will know i am a techo tragic. i am looking at installing another 110 amp panel (same as the first one) from what i have read on google brain there are two ways to do it, series or parellel ,the panels are already pre wired to anderson plugs so the easiest way is to parallel them ,is it worth wiring them in series to increase the voltage or keep the voltage and increase the amps? i have read if done in parallel you can get away with shaded areas on one panel and get a good charge, but if in series you only get the lowest charge from the shaded area ,i am probably getting involved in these things as at present i am not able to get on the road due to family issues (i have greater solar capacity when on the road its only an issue when parked up at home)
Solar SOLAR PANELS ? IN SERIES OR IN PARALLEL ?
- Thread starter poor but proud
- Start date
I would go Parallel, mainly because its the amps that do the charging, if your cable run is something like 20 mts or something then go series otherwise though 110w panel is a good size for just keeping the battery happy, should be rated about 6a so really work on 4a add another and look at 8a, overall, be rated at 12a ish but really I knock 30% off and gives a better indication of what you can generally get out of them most of the time ............. If you go series the extra volts won't do anything to charge the battery and you will still only have the same amps, best used when the cable run is long...
I have a 46v house panel beside the garage to keep the Rangers aux battery charged it gives out enough to keep things happy but only about 4a .... the 200w on van shunts more juice as its 18v ....
I have a 46v house panel beside the garage to keep the Rangers aux battery charged it gives out enough to keep things happy but only about 4a .... the 200w on van shunts more juice as its 18v ....
this all started when it appeared my house battery was not holding charge, i started to add up the parasites in the setup. by the time you tally every led that glow 24/7,usb charge ports,auto fan battery top ups,appliance standby,status gauges, tv antenna ,it adds up to a fair chunk of the stored power it definatly pays to make sure appliances are disconnected,as in a lot of older vans they installed automotive radio/cd player in such a way that brings them to standy each time the power is turned on they draw 8amps even when not actually turned on,i have removed the fuse from that one and pull the plug on the tv when not in use
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Oh yeah, those radios are power vultures, tracked a parasite draw on mate and it was the radio well the mini amp , radio could be turned of but this thing was always on sucking power, side cutters ended its life ..........
Some one forgot to plug in external panel to utes aux battery yesterday, so with draw fringe set for -10 the old 120ah AGM was a bit sad come smoko today, Ranger now parked lined up ready to hook up in morning and aux battery plugged into portable 120w while the draw fridge is plugged into van, I must say my Aldi 120w panel is over 10 years old, done heaps of work, with battery at 12.2v and when the sun poked its head out from clouds it was shunting 7.4a at one stage, must have had it pointed in just the right direction, today been running from 1a to 6a, 7a best Ive ever seen since its 18v, 120w rated at 6.4a max, so its still pushing out good power after all these years going thru my ProStar 35 PWM controller, might be a PWM but its one of the best and seems the MPPT beats it in low light, low angle sun situations from comparison tests Ive done .................. Anyway quite chuffed with the Aldi unit, mind you I binned the controller it came with on the first day ...........
I reckon just go the parallel, more juice for the battery then.......................... when mine is parked up just the Epever controller and a gas alarm are on everything else shut down, well sometimes the breaksafe battery is on charge as someone often forgets to turn it off but all in all nothing serious and just gives the battery some exercise........ I have switches for gear like TV/Radio and the diesel heater, turn on when I want it..... if I ever build a roof over my van I will plug into the 200w job I have on my shed roof that will keep it all happy then.... having controlller that will accept up to 60v or more is a good thing, as old house panels you can get for free or about $35 ... though output less than the RV 18v jobs.
Some one forgot to plug in external panel to utes aux battery yesterday, so with draw fringe set for -10 the old 120ah AGM was a bit sad come smoko today, Ranger now parked lined up ready to hook up in morning and aux battery plugged into portable 120w while the draw fridge is plugged into van, I must say my Aldi 120w panel is over 10 years old, done heaps of work, with battery at 12.2v and when the sun poked its head out from clouds it was shunting 7.4a at one stage, must have had it pointed in just the right direction, today been running from 1a to 6a, 7a best Ive ever seen since its 18v, 120w rated at 6.4a max, so its still pushing out good power after all these years going thru my ProStar 35 PWM controller, might be a PWM but its one of the best and seems the MPPT beats it in low light, low angle sun situations from comparison tests Ive done .................. Anyway quite chuffed with the Aldi unit, mind you I binned the controller it came with on the first day ...........
I reckon just go the parallel, more juice for the battery then.......................... when mine is parked up just the Epever controller and a gas alarm are on everything else shut down, well sometimes the breaksafe battery is on charge as someone often forgets to turn it off but all in all nothing serious and just gives the battery some exercise........ I have switches for gear like TV/Radio and the diesel heater, turn on when I want it..... if I ever build a roof over my van I will plug into the 200w job I have on my shed roof that will keep it all happy then.... having controlller that will accept up to 60v or more is a good thing, as old house panels you can get for free or about $35 ... though output less than the RV 18v jobs.
I have always run my solar panels in series rather than parallel. Yes, when you run two or more solar panels in series it effectively creates one big solar panel with corresponding voltage output. Therefore if an area of any panel is partially or fully shaded then it reduces the whole output to the lowest cell generation.
As opposed to joined in Parallel where one of the panels might be shaded but the other/s will still produce their max amps output.
The reason I prefer series is that the voltage is much higher going to the MPPT...plus...higher voltage also means smaller cables can carry the higher voltage with much less resistance as opposed to amps over distance. Big amps need thick cables over distance.
Seriously when you look at the cabling provided by many solar panel retailers, along with a some very basic PWM controllers, then add cables that are pathetically thin with heaps of resistance...and they really expect serious amperage to be carried over many metres without loss of input?
If you have 2 x 18v, 8 amp panels in parallel you'll get potentially at max 18v and 16 amps to the MPPT...when the sunlight begins to fall the voltage will fall dramatically as well, even falling to under 12v which is not enough to charge a battery as you need at least 14v to do so...amps aren't much good without good voltage to kick them along. ( That is my understanding and I stand to be corrected if wrong)
Conversely, if you have 2 x 18v, 8 amp panels in series, you'll see up to 36v and 8 amps at the MPPT. The MPPT will convert the 36 volts to usable amps. as the sunlight begins to fade you will still be getting a reasonable voltage to the MPPT in excess of the min of around 14v which the batteries need to add charge.
Series will give extra input in low light situations, overcast days etc. But...that said, often both series and parallel can give similar results. I just prefer the series set up as I get a tad extra input in the early mornings and late afternoons...
As opposed to joined in Parallel where one of the panels might be shaded but the other/s will still produce their max amps output.
The reason I prefer series is that the voltage is much higher going to the MPPT...plus...higher voltage also means smaller cables can carry the higher voltage with much less resistance as opposed to amps over distance. Big amps need thick cables over distance.
Seriously when you look at the cabling provided by many solar panel retailers, along with a some very basic PWM controllers, then add cables that are pathetically thin with heaps of resistance...and they really expect serious amperage to be carried over many metres without loss of input?
If you have 2 x 18v, 8 amp panels in parallel you'll get potentially at max 18v and 16 amps to the MPPT...when the sunlight begins to fall the voltage will fall dramatically as well, even falling to under 12v which is not enough to charge a battery as you need at least 14v to do so...amps aren't much good without good voltage to kick them along. ( That is my understanding and I stand to be corrected if wrong)
Conversely, if you have 2 x 18v, 8 amp panels in series, you'll see up to 36v and 8 amps at the MPPT. The MPPT will convert the 36 volts to usable amps. as the sunlight begins to fade you will still be getting a reasonable voltage to the MPPT in excess of the min of around 14v which the batteries need to add charge.
Series will give extra input in low light situations, overcast days etc. But...that said, often both series and parallel can give similar results. I just prefer the series set up as I get a tad extra input in the early mornings and late afternoons...
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well this could lead to a spirited debate, one for, one against, let the debate begin. i am non technical so i was leaning towards parallel as it was just use a twin anderson to one , going to the mppt ,living in the suburbs the shading issue makes me lean towards parallel also the distance from the panels to the controller is less than 3 meters