SJ-Chris wrote:
StirCrazy wrote:
SJ-Chris wrote:
That is a good question. Strangely, I didn't even think about connecting them in series. I connected them in parallel. I can appreciate how in series they would collectively get to say 14v+ earlier in the day and stay at 14v+ later in the evening. That would generate a little extra charging. Does anyone have any real life data on how much/little gain this ends up being in the real world? Would be interesting to know. Since all the panels are connected on the roof it wouldn't be terribly hard to re-wire them in series.
I guess the gain comes from the time between when the individual panels are producing ~5v to the time they are producing ~14v (and the reverse as the sun goes down). I'm curious....is this ~10 minutes in the morning and ~10 minutes in the evening? 20 minutes on each end?? Anyone know?
I suppose when I go boondocking next if I'm up before the sun I can keep an eye on my solar charge controller and measure the time...
PS: Solar is addictive.
Happy camping!
Chris
don't have any real numbers only observation. my 5th wheel has 480 watts of 12v panels on a PWM controler and my camper has a 325 watt 24V split cell panel on a MPPT controler. the overall output total per day is more from the 325 watt set up. for morning my camper will start charging at 7 am with about 0.5 amps where the 5th wheel wont put that out till about 8 to 8:30 up here. so at least 1 to 2 AH more just from reaching that higher voltage sooner
So maybe 1-2 extra AH in the morning and 1-2 extra AH in the evening.
2-4AH extra per day.
On a sunny day, your 325w system likely has the ability (batteries permitting) to generate ~100AH of charge to the batteries. So 2-4 extra AH would be about 2-4% more overall charge series vs parallel. Certainly it's not a bad thing, but for me it's not worth getting up on the roof and rewiring to series for just 2-4%. If I was doing it from scratch, yes I would probably do them in series next time.
Happy Camping!
Chris
no thats not it, it averages about 2amps higher output through out the day also. so if we have a nice sunny day I get the extra say 3AH for the extra time morning and night, then I get an extra 8 to 18AH for the rest of the day depending on the time of year. now I don't know if I switched my curent 12V panels on my 5th wheel to series if it would get that same efficiency , I think part of it has to do with the split cell panel on the camper and it also has a higher effecniency rating, and the ones on the 5th wheel are you basic 12V go power panels, so probably over priced garbage.. Ill see up to 23amp going to my battery in the peak hours of the day with the 24V panel, but the 5th wheel with 30somthing percent more panel wattage at best does 21amps...... but mostly 20.
Steve
