Combining 2 solar panel pairs

[jwcole04]

I have a failed naturesgenerator elite system which I expanded to 2 pods and 4 solar panels. I tried working with ng support to fix the system to no avail. It's a long story I don't need to go into, but suffice it to say their claim of lifetime support is BS.

I have 4 perfectly good panels I mounted on my patio roof and want to use them with a diy system - and have been researching charge controllers and inverters.

The panels are configured in pairs with parallel connections on each pair. To see if they were working I cut the cable and stripped the wires for the first pair and used a multimeter to test them. On a partly cloudy day I got a reading of 18v for one pair - same on the second pair. I twisted the 2 positive wires together from each pair - same negative wires and still got a reading of 18v.

Now my question - why didn't I get a reading of 36v?

Thanks to anyone who can help. I'd like to use all 4 panels if possible.

 

[timselectric]

When connected in series.
Voltage is added together, and amperage remains the same.
When connected in parallel.
Voltage remains the same, and amperage is added together.

 

[Supervstech]

In parallel, the amperage goes up, the voltage stays the same.

 

[Supervstech]

To get series voltage rise, you need to connect the pairs positive to negative.

So, two panels will be panel 1 positive to panel 2 negative.
Panel 2 positive to the charge controller. Panel 1 negative to the charge controller.

 

[jwcole04]

To get series voltage rise, you need to connect the pairs positive to negative.

So, two panels will be panel 1 positive to panel 2 negative.
Panel 2 positive to the charge controller. Panel 1 negative to the charge controller.

Thanks Supervstech - I'll try it when we have some light - it's 6:30am now in Seattle.

 

[jwcole04]

To get series voltage rise, you need to connect the pairs positive to negative.

So, two panels will be panel 1 positive to panel 2 negative.
Panel 2 positive to the charge controller. Panel 1 negative to the charge controller.

That's it- thanks man!

Each pair showed 19v .38a
Connected each pair per your instructions showed 39v .22a

Does the lower amps for 4 panels look right? I don't really understand, but don't need to. Also, these are 100w panels.

I'm going to use one of my boat batteries for storage, and possibly add a second. It's a West Marine lead calcium battery, and although it doesn't say so, I'm pretty sure it's a deep cycle. Is there something better I can use?

Thanks again for your help.

 

[Supervstech]

Amps will change based on sunlight intensity and load demands.

I am not familiar with that type of battery, so i cant say.
I do like the LiFePO4 batteries, but they cant tolerate cold weather.

Post your plans, and the specs on your equipment if you need help with anything.

 

[jwcole04]

Amps will change based on sunlight intensity and load demands.

I am not familiar with that type of battery, so i cant say.
I do like the LiFePO4 batteries, but they cant tolerate cold weather.

Post your plans, and the specs on your equipment if you need help with anything.

Thanks Supervstech!

 

[jwcole04]

I have a Victron energy smartsolar mppt 100/30 charge controller hooked to a LiFePO4 battery. The multimeter shows 42v coming from the panels, but I get no readings (solar volts, current, solar watts, etc.) in the phone app except battery volts (13v). The app gives a message that the panel volts must be 5v above the battery volts which they are obviously. Do you have any idea what the problem could be?

Thanks

 

[Supervstech]

What are the charge settings on the controller?
It may think 13v is full.

 

[jwcole04]

What are the charge settings on the controller?
It may think 13v is full.

the charge setting is 7 which is Lifepo4. The battery is new and is 100% charged - I checked it with a meter. Is that the problem? Should I run an applicance on the inverter for a while to draw down the battery charge?

 

[FishHog]

If your battery is fully charged the charge controller isn’t going to put any power to the battery. Drain the battery some and then watch what is being generated

 

[jwcole04]

If your battery is fully charged the charge controller isn’t going to put any power to the battery. Drain the battery some and then watch what is being generated

Thanks FishHog!