parrarel or series circuit

[johnbythesea]

hello all

when i first installed my solar system (two 175w panels) i choose to wire it as a parrarel circuit, i can't remember why at the time, but i believed it to be the best method. my panels, and battery are 12vs, because its parallel, i understand this to mean that i am now inputting a 24w power supply into my charge controller. I've been advised that this is ok as my charge controller is a 30A MPPT and specifies that it is suitable for either 12v or 24v. my questions are; is this still ok with a 12v battery and secondly does having the solar panels is a parallel circuit affect its performance in anyway?

the system has been working with out any noticeable problems for over 6 months

[zingaro]

Im watching your post for some answers as ive the same question. Wiring in parallel keep the voltage the same but increases the amps. Ive notices a few post with wiring in series and the controller (mppt) adjust the voltage.

I too am wanting input on your question ...z

[Mike90250]

It is true that batteries in parallel increases AMPs, and in series - VOLTS will increase.

What to do ? Decide what the system watt hour demand will be. Discover what the peak amps will be. Design a system with large enough Ah batteries, to use just 1 series string to get the required amps - it may require using 4V & 2V battery packs.

this link http://www.smartgauge.co.uk/batt_con.html will introduce you to the problems of trying to construct a large battery bank from parallel batteries. (possible, but tricky)


And we generally recommend using a cheap set of Golf Cart [ GC2 ] batteries as learning devices. They won't last more than a couple years, but you are less likely to ruin an expensive set of batteries from a silly learning mistake.

[posplayr]

this link http://www.smartgauge.co.uk/batt_con.html will introduce you to the problems of trying to construct a large battery bank from parallel batteries. (possible, but tricky)

.

Interesting article on something an EE would recognise as second nature but is hard to explain to a layman (i.e. single point grounding and power distribution).

Without trying to make the article more complicated (I think it is well written), given the ultra low resistances described in the article (0.015 ohms), there probably should have been a recommendation to use contact cleaner (e.g. DeOxit) to keep the terminals clean.

[SunEagle]

hello all

when i first installed my solar system (two 175w panels) i choose to wire it as a parrarel circuit, i can't remember why at the time, but i believed it to be the best method. my panels, and battery are 12vs, because its parallel, i understand this to mean that i am now inputting a 24w power supply into my charge controller. I've been advised that this is ok as my charge controller is a 30A MPPT and specifies that it is suitable for either 12v or 24v. my questions are; is this still ok with a 12v battery and secondly does having the solar panels is a parallel circuit affect its performance in anyway?

the system has been working with out any noticeable problems for over 6 months

The decision to wire the solar panels in series or parallel is mostly dependent on the type of charge controller you have (PWM or MPPT) and it's DC voltage input and DC amperage output ratings.

A MPPT CC usually has a much higher DC volt input rating then a PWM type. So depending on the Voc of your panels wiring them in series is normal for MPPT CC.

The panels do not perform any different wired in series or parallel. The output changes (series - volts are added, amps stay the same) (parallel - volts stay the same, amps are added). The performance is based on the CC.

PWM - Amps in = Amps out. So if you need more amps then wire the panels in parallel.
MPPT - Watts in = Watts out. It really doesn't matter how the panels are wired, the CC amp output will be dependent on the total panel wattage divided by the battery voltage.

What are the specifications of your solar panels (Voc,Vmp, Imp & Isc) and the make and model of your 30A MPPT CC?

Knowing that info will help us guide you with your system wiring.