350 watt panel but only 13v on charge Controller

[endaman]

I just setup a small solar system in my shed.

I have an epever charge controller 20amp, 12v\24v, PCM, this one: https://www.amazon.co.uk/gp/product/B07R5SVGQF

I have a 350 w Solar panel, here are the details
https://static.solartricity.ie/wp-content/uploads/2020/04/Longi-350-Watt-panels.pdf

I believe that panel can do up to 35 volts.

I have a 12 v 120 amph deep cycle lead acid battery, this one: https://www.amazon.co.uk/gp/product/B01DT5564C/ref=ppx_yo_dt_b_asin_title_o09_s00?ie=UTF8&psc=1

My problem is I can not get higher that 13 v on my charge controller. The most I got from the panel was 150 watts with blue skies.

Could the charge controller be staying at 13 v because I have a 12 v battery, just wondering how I can not get the max out of my new solar panel.

Thanks, em

 

[snoobler]

40.5Voc
33.3Vmp


That's a PWM charge controller. Your panel voltage is too high. The PWM controller pulls the panel down to battery voltage and the panel can only put out somewhere between its Isc and Imp. 13V * 8.5W = 111W

Replace panel with panels having Vmp around 18V or replace PWM controller with MPPT controller.

 

[Bob142]

I just setup a small solar system in my shed.

I have an epever charge controller, PCM, this one: https://www.amazon.co.uk/gp/product/B07R5SVGQF

I have a 350 w Solar panel, here are the details
https://static.solartricity.ie/wp-content/uploads/2020/04/Longi-350-Watt-panels.pdf

I believe that panel can do up to 35 volts.

I have a 12 v 120 amph deep cycle lead acid battery, this one: https://www.amazon.co.uk/gp/product/B01DT5564C/ref=ppx_yo_dt_b_asin_title_o09_s00?ie=UTF8&psc=1

My problem is I can not get higher that 13 v on my charge controller. The most I got from the panel was 150 watts with blue skies.

Could the charge controller be staying at 13 v because I have a 12 v battery, just wondering how I can not get the max out of my new solar panel.

Thanks, em

Welcome to the forum.

The short version of the story is that you need to upgrade to an MPPT charge controller to take full advantage of your solar panel with a 12V battery bank.

PWM controllers are basically just a switch that connects the panel to your battery. That pulls the panel voltage down to battery voltage while charging. That's why you only see 13V. MPPT charge controllers are DC to DC converters designed to optimize the power from your panel to your battery. Some light reading from Victron on the subject: https://www.victronenergy.com/uploa...Which-solar-charge-controller-PWM-or-MPPT.pdf

 

[endaman]

Thanks, this is great information for me, I really appreciate it.

I like my 350 watt panel so maybe I will move to an MPPT charge controller,

would this suffice: https://www.amazon.co.uk/Fuhuihe-Controller-Display-Multiple-Control/dp/B07H4J1C7X/ref=sr_1_5?dchild=1&keywords=mppt+solar+charge+controller&qid=1599427323&refinements=p_76:419158031,p_72:419154031&rnid=419152031&rps=1&sr=8-5

Or maybe I need a better one? The comments are not very promising on that one.

 

[snoobler]

That is not MPPT. It is a fake. You're going to have to spend $100-ish

 

[snoobler]

This 30A should do it;

Fuhuihe MPPT Solar Charge Controller 30 amp 12V 24V Auto, 30A Solar Charge Controller Max 100V Input Negative Grounded Solar Reulator : Amazon.co.uk: Business, Industry & Science

Fuhuihe MPPT Solar Charge Controller 30 amp 12V 24V Auto, 30A Solar Charge Controller Max 100V Input Negative Grounded Solar Reulator : Amazon.co.uk: Business, Industry & Science

www.amazon.co.uk

 

[endaman]

I should have spent time on this forum before starting my project.

Let me check that one out, thanks.

 

[endaman]

I would like to get another of those 350w panels sometime. Would this still be a good option: https://www.amazon.co.uk/Fuhuihe-Controller-Monitor-Temp-Sensor-Package/dp/B07H5FNXCR

 

[snoobler]

It looks as though you linked the same thing. Looking back at your battery capacity, you don't want much more than 12-18A of charging, which means your existing panel is too much and you should either limit the peak charge current in the controller (if that's an option), or add a battery.

In any case, if you added another panel, you'd need a controller or additional controllers capable of a total of 750/12 = 62.5A, and you would need over 420Ah of battery capacity to handle that current.

 

[ghostwriter66]

This 30A should do it;

Fuhuihe MPPT Solar Charge Controller 30 amp 12V 24V Auto, 30A Solar Charge Controller Max 100V Input Negative Grounded Solar Reulator : Amazon.co.uk: Business, Industry & Science

Fuhuihe MPPT Solar Charge Controller 30 amp 12V 24V Auto, 30A Solar Charge Controller Max 100V Input Negative Grounded Solar Reulator : Amazon.co.uk: Business, Industry & Science

www.amazon.co.uk

Figure out what your think your final PROJECT looks like and then get the right MPPT to fit it ... otherwise you are going from 20A to 30A to 40A to ....

.02

 

[endaman]

Thanks,

My final project will be 220 ampH, which I think will give me light and the ability to run a stove pump for a few days in the event of a power outage, I also will run a dog electric fence from this as well also low wattage and maybe another low watt water pump for an oil burner.

I was hoping that 350 watt solar panel would be enough to keep those two batteries topped up, even here in Ireland. 2 x 120 ampHr, deep cycle lead acid flooded.

So maybe this is the CR for me: https://www.amazon.co.uk/Fuhuihe-Controller-Monitor-Temp-Sensor-Package/dp/B07H5FNXCR

and in time I can add another battery, or are you saying I should add that other battery now?