currently have a 160w folding solar panel that connects to my 130ah agm battery.
have purchased (and awaiting delivery) of a mppt controller to replave the pwm that is currently on the panels.
question is, currently the panels wired in parallel into the pwm. should i be changing this to have the panels in series into the mppt or is it ok as parallel?
You could wire them in series. There is a small advantage in some situations but not much really for a small setup. What are the specs of the panels.
Secondly now is the time to fit the regulator near the battery instead of on the panels !! That will possibly give you a better working setup.
Thirdly! Note that cheap MPPT regulators are mostly fakes ! and are really PWM regs with a fancy sticker. You have been warned. If so then series wiring your two panels will loose half their power most of the time !
I have a portable setup 6 x 20 watt panels. I have tested them 6 in parallel, 2 in series in 3 parallel sets & 3 in series in 2 parallel sets.
I didn't test them long enough to see if there was any noticeably difference. In the end I stuck with the manufacturer's recommendation of 2 in series.
The advantage of this is that early in the morning or on non ideal days you will get a bit more power.
But the key thing is to put the controller near the battery & plug the panels in & have some cables for extention so the panel do not get any shadows. A very small shadow will dramatically reduce output.
I'm using a Victron 100/20 MPPT.
__________________
Procrastination, mankind's greatest labour saving device!
50L custom fuel rack 6x20W 100/20mppt 4x26Ah gel 28L super insulated fridge TPMS 3 ARB compressors heatsink fan cooled 4L tank aftercooler Air/water OCD cleaning 4 stage car acoustic insulation.
Thanks for that info. They are regular panels so should work OK. What is the regulator type and spec you are getting.
In a past time I had some portable panels but found them too heavy to handle, getting them in and out etc. So I just disconnected the hinges and rewired them so they could be used singly or together. And I made a long extension cord to use if needed to chase the sun easier. But I did fit the reg near the battery. Later I set it up for 4 panels wired 2 in series x 2 strings into a MPPT reg all individually plugging into a junction box.
Jaahn wrote:Thirdly! Note that cheap MPPT regulators are mostly fakes ! and are really PWM regs with a fancy sticker.
In regard to product sourced from Ebay and the like I agree with Jaahn.
Having run a (genuine) MPPT controller on 180W of panels for a few years now I'm not convinced they are worth the extra cost over a quality PWM controller - although they probably generate less RF emission which is a good thing.
Do check carefully that your new controller actually operates as it should and that it produces (close to) the maximum current the panels can generate. I bought a folding pair of 140W panels which came with a controller, even in good sun that controller only produced about 3A - replacing it with a quality PWM the current increased to about 8A! The Ebay supplier told me I didn't know what I was doing however with 40 years of electronics design behind me I rather think I do :)
__________________
"I beseech you in the bowels of Christ think it possible you may be mistaken"
Oliver Cromwell, 3rd August 1650 - in a letter to the General Assembly of the Kirk of Scotland
I bought a folding pair of 140W panels which came with a controller, even in good sun that controller only produced about 3A - replacing it with a quality PWM the current increased to about 8A!
If the controller was fake, then I would be concerned about the "140W" panels. That said, 8A seems about right for PWM.
-- Edited by dorian on Monday 12th of April 2021 08:46:01 AM
__________________
"No friend ever served me, and no enemy ever wronged me, whom I have not repaid in full."
I bought a folding pair of 140W panels which came with a controller, even in good sun that controller only produced about 3A - replacing it with a quality PWM the current increased to about 8A!
If the controller was fake, then I would be concerned about the "140W" panels. That said, 8A seems about right for PWM.
Indeed, so was i! But the panels are fine and have been in use for a few years and, via the MPPT, produce about 9A on a good summer day. A shame the supplier was prepared to ruin a good system for the sake of spending another $5 or $10 on a better controller. I suppose they rely upon the concept that most people will never know, they'll just think "these new-fangled solar panels are not as good as I hoped."
__________________
"I beseech you in the bowels of Christ think it possible you may be mistaken"
Oliver Cromwell, 3rd August 1650 - in a letter to the General Assembly of the Kirk of Scotland
If so then series wiring your two panels will loose half their power most of the time !
