How To Connect Two Solar Panels To One Battery

How To Connect Two Solar Panels To One Battery

So, you have bought a solar kit or Portable solar panels and want to connect them to a battery, but are a little confused? don’t worry, it is very simple to connect two solar panels to one controller and battery. In this article, we will explain to you how to connect the solar panels. If you have any doubts regarding the steps, you can let us know in the comments section below. 

Connecting Two Solar Panels To One Battery

Connecting Two Solar Panels To One Battery

Step 1: Connect Your Battery To The Controller

The primary step is to connect your battery to the charge controller. You must do this action first. If you connect the solar panels to the charge controller, you might run the risk of destroying the charge controller while doing so. (If you are searching for a good solar charge controller, you might want to read our article on the best solar charge controller to choose a good charge controller)

Wire density depends on the existing that your charge controller is going to send to the batteries. For instance, the Renogy Rover 20A provides 20 amps to the battery. You require wires that can bring 20Amps or more and utilize a 20Amp fuse on the wire. Only fuse the positive wire. If you are using a flexible copper wire, you require this AWG12 wire with this fuse. Place the fuse as near the battery terminals as possible.

You ought to wind up with a setup like this:

Also Read: Complete Guide on Solar Powered Televisions

Step 2: Connect Your Solar Panels

In this action, you are going to link your two solar panels together.

This can be performed in series or parallel. Connecting your 2 panels in series will build up the voltage, while parallel will build up the current. If you wire in series, you require a smaller sized size of wire than parallel. Continue reading to find out “how to wire solar panels in series”.

The fuse ranking is defined in the solar panel datasheet or on the sticker label at the back of the panel. You can use an inline MC4 port fuse.

Step 3: Connect The 2 Solar Panels To The Charge Controller

The wire from the solar panel will be too short to run to your charge controller. Use this wire to extend it so it can reach your charge controller. Most of the time, you are going to utilize the series connection. So we will continue the example with the series connection. Position your charge controller as close to your batteries as possible. Put your charge controller as near to the two solar panels as possible to lessen wire losses. If you have a remaining wire from the solar panels to the charge controller, then shorten them to decrease losses.

Your DIY planetary system will now look like this:

Step 4: Connect The Loads

Connect the loads

If you have little DC loads, you can connect them to the load terminal on the charge controller. If you want to utilize an inverter, I advise using the battery terminals. See the following diagram as an example.

The size of the wires will depend upon the present that will go through the wires. If the inverter uses 100 amps of the current, you require to size your cable and merges for that existing. 

Once completed, you can use the solar panels to heat you greenhouse or run a refrigerator,

Also Read: Best Indoor Solar Lights


Linking 2 solar panels to one charge controller and one battery is not that difficult to do. You require to follow these instructions on the page and utilize the circuit diagrams I have shown you. If you have questions, make sure to send me an e-mail or leave a remark below.


1. Can You Link Two Solar Panels To One Battery?

You might think we have already answered this. Nevertheless, there’s one consideration. To power a dual battery system, you’ll require to connect the panels in parallel.

2. How To Link Two Solar Panels In Parallel?

Linking 2 solar panels in parallel. Link the negatives to the negatives and positives to the positives.

To get maximum output, you would require both panels to have the same optimum voltage. For example, the 115W SunPower solar blanket has the following scores:

Optimum ranked voltage = 19.8 V.

Optimum ranked existing = 5.8 A.

Optimum rated power = Volts x Existing = 19.8 x 5.8 = 114.8 W.

Connecting two of these blankets in parallel will give you:

Optimum rated power = 2 x 19.8 x 5.8 = 229.6 W.

Nevertheless, if you have two panels with various output scores, the optimum voltage for the system is identified by the panel with the most affordable optimum ranked voltage.

Baffled? Let’s take a look at what takes place when we connect our solar panel and solar blanket.


Optimum ranked voltage = 18.0 V.

Optimum rated existing = 11.1 A.


Maximum rated voltage = 19.8 V.

Optimum rated existing = 5.8 A.

Connecting them in parallel will give you:

Maximum rated power = (18.0 x 11.1) + (18.0 x 5.8) = 304.2 W.

The output of the solar blankets will therefore be de-rated to (18.0 x 5.8 =-RRB- 104.4 W or by 10%.

In our case, it’s not a big offer.

It’s more when you have a bank of panels linked in parallel, for instance, 6 on the roof of a motorhome. Then you start to lose significant capability.

Also Read: Best Solar Laptop Chargers

3. How To Connect Multiple Solar Panels To One Battery?

You can link them in parallel, offering your battery management system can deal with the maximum input power. How do you calculate optimum input power? See “Can you link two solar panels to one battery?” above.

4. How Do You Match A Solar Panel To A Battery?

Figure out what gadgets you wish to run. For instance:

A refrigerator draws 7A and runs for 20% of the day (24 hours). So average existing draw in one hour is 7 x 0.2 = 1.4 Ah.

An inverter draws 45A for 5% of the day. So average existing attract one hour is 45 x 0.05 = 2.25 Ah.

USB ports and LED lights draw 5A for 20% of the day. So typical present draw is 5 x 0.2 = 1.0 Ah.

The water pump draws 7.5 A for 5% of the day. The average current draw is therefore 7.5 x 0.05 = 0.375 Ah.

Add them together:

( 1.4 + 2.25 + 1.0 + 0.375) = 5.0 Ah.

Let’s round it to 6Ah.

What does this indicate? Well, in 24 hours you.

‘ll use 24 x 6 = 144Ah. State 150Ah.

Your solar panels must be capable of providing this. Let’s size your solar panels:

Assume an optimum of 6 sunshine hours.

So in 6 hours, they must supply 150Ah to the battery or 25A (150/6).

If we assume that the solar panels supply 12V, at 25A, you will require a solar panel capable of 300W (25×12) 

Enable at least 10% additional capability:

So, you would require 300 x 1.1 = 330W of solar panels.

Your probable match will be 350W.

5. What Size Battery Do You Require?

Deep cycle batteries do not like to drop below 50% capability (Lithium batteries can go much lower without damage).

You use 150Ah in 24 hr. However, you can’t discharge listed below 50%. So you require 300Ah.

The solar panels supply 150Ah in 24 hr. They will recharge your battery to 100% every day (assuming 6 hours of available sunshine).

In Summary:

You do not simply match the solar panel to the battery. You need to understand the loads on the battery, size the battery to match the load and after that size the solar panels to match both the load and the battery.

I informed you the answer wasn’t basic!

Also Read: Best Solar Generator Reviews & Buyer’s Guide

6. Can A Solar Panel Overcharge A Battery?

Yes! Never link a solar panel directly to a battery. It requires a regulator in between the panel and the battery.

The regulator will either be mounted on the back of the solar panel or within a battery management system (BMS). The regulator controls (funny that!) the voltage from the solar panel and safeguards the battery from over-voltage.

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  1. Hi!am antony happy to know all this ur work is good.but I have one question is it a must panel to have equall watts?

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