Solar charge controllers transfer produced energy in solar modules to DC bus from which battery is charged and DC loads get power supply.
According to energy during transfer, solar charge controllers can share in two groups:

Almost all controllers on the market belong to this group. Solar modules in system with this controllers never work with maximal possible power, because controller force the voltage of solar module to value of battery voltage. Energy which stays unuse is higher if the battery is more empty (because the difference between voltage at which modules production is maximum and battery voltage is bigger and bigger). Exactly when the energy is most necessary, result is the biggest losses of energy which can be above 30%, from total produced energy by solar modules.

This technology is called MPPT (Maximum Power Point Tracking) and because of their price applyed just in bigger solar systems. Decreasing the prices of electronics, recently the use of MPPT controllers became more repay even in the smaller systems.

MPPT controllers on their input always keep solar module voltage on value at which the power of modules is maximum. The voltage of solar module for maximum power is always higher than the battery voltage. Controller actually works as transformer connected between solar modules and battery. In transfer of power from module to battery, charging current increases proportionally to reduction of voltage. Boost of charging current in relation to other type charge controllers is bigger if the battery is more empty (more charging when more is needed).

Additional advantage of MPPT controller is that they can work with modules totally unstandard voltages. Beside that it is provided that in the same system you can have solar modules and and batteries with different voltages.

Our offer includes both type controllers with module voltage area from 12V to 140V, voltage battery from 12V-60V and charge current per controller 5A-60A.