Schneider C40 charge/load controller

[Chacabuco]

Greetings,

I'm just trying to do a quick test, I have a schenider C40 charge/load controller, a 75 watt solar panel with a maximum voltage of 14.67 Volts and a 12 volts deep cycle battery. As far as I understand, I just have to make the connections of the panel to the controller and to the battery. My question is: what happens if the battery has a voltage higher than the one the panel is giving out? Will it not charge the batteries? What is normally done in this case?

Thank you.

[inetdog]

Greetings,

I'm just trying to do a quick test, I have a schenider C40 charge/load controller, a 75 watt solar panel with a maximum voltage of 14.67 Volts and a 12 volts deep cycle battery. As far as I understand, I just have to make the connections of the panel to the controller and to the battery. My question is: what happens if the battery has a voltage higher than the one the panel is giving out? Will it not charge the batteries? What is normally done in this case?

Thank you.

To charge a nominal 12V battery requires a panel with a maximum power voltage (V_mp) of around 18V.
Your panel will not do the job, period. It will be at its best connected directly to the battery without a CC in between, which may be OK for that small a panel, depending on the AH rating of your battery.

[Sunking]

Very simple you have a PWM Controller. That makes the math very simple.

Input Current = Output Current.

Simple?

It takes a minimum 17 to 18 volts for every 12 volts of battery to charge it. 18 for a 12 volt battery. 36 volts for a 24 volt battery
Understand the simple math?

Very expensive battery panels have 36 cells for every 12 volts of battery. Each cell develops 1/2 volt.

36 cells is 18 volts right? Again simple math right?

A 100 watt 12 volt battery panels with 36 cells has a Vmp (voltagge at max power) = 18 volts, and an Imp = 5.3 amps. Power = Voltage x Amps so 18 volts x 5.3 amps = 100 watts.

Again very simple math right?

So with a 100 watt panel on a 12 volt battery 5.3 amps x 12 volts = 66 watts.

Again very simple math right?







But what if we used a inexpensive Grid Tied panel or even a expensive battery panel with a MPPT controller. What changes? .

MPPT Output Current = Panel Wattage / Battery Voltage.

Simple again right?

A 100 watt panel / 12 volts = 8.3 amps.

Simple right? 8.3 is greater than 5.3 right?