I suspect this 2 misunderstanding is where companies like west marine advise readers that a solar panel with 1 5 of amp hour capacity in current potential does not need a controller.
Do solar panel need to match the controller.
The safest way to figure out if you need a charge controller is to take battery amp hour capacity and divide this by the solar panel max.
Again this is not chock full like unregulated solar can do just full enough to stop pushing them at absorption levels and switch to a float voltage.
You connect solar panels in series when you want to get a higher voltage.
That way you get 11 7 x 5 2 60 watts going into your battery bank instead of 100 watts.
In a 12v battery system you took a 12v solar module watched carefully that the maximum pv current would not exceed the charge controller maximum current and the system would work.
Unfortunately due to the fact that with pwm controllers the pv module is not feeding the battery from its maximum power point mpp the system loses a lot of energy.
The pmw solar charge controller will match the solar panels voltage to that of the battery bank that is 11 7 v but keep the current at 5 2a.
Do i always need a solar charge controller.
There are two main types of connecting solar panels in series or in parallel.
For example if you have a 100 amp hour battery and a 10 watt panel you take 100 and divide it by 6 600ma and you get 166 6.
Anything beyond that and you do.
If the number is less than 200 than you need a controller.
The solar power you want to generate the other system components such as a charge controller battery and inverter.
Different types of solar charge controllers.
Amperage ratings can be between 1 60 amps and voltage ratings from 6 60 volts.
There are three different locations that we recommend installing fuses or breakers.
The charge process is performed in a smart or intelligent way.
If a panel puts out 2 watts or less for each 50 battery amp hours you probably don t need a charge controller.
You don t need a charge controller with small 1 to 5 watt panels.
First between the charge controller and battery bank second between the charge controller and solar panels and third would be between the battery bank and inverter to determine the fuse size needed between the charge controller and battery bank you simply match the amperage rating on the charge controller.
The load is then responsible for the discharging function from the controller if it is connected to the controller.
A solar charge controller is designed to receive power from a solar panel or array of panels and use it to charge a battery or bank of batteries.
The good news though is that the power going into your battery array increases as it gets charged.
Life used to be so simple.
The most common pv charge controllers come in 12 24 and 48 volts.
The solar panel connects to the controller through positive and negative leads only creating a charging function when the controller is connected to a battery.
