Sizing Guide for Solar Charge Controllers

Wednesday, 3 August 2016  |  Admin

Sizing guide for solar charge controllers

We stock a wide range of both PWM and MPPT solar charge controllers. The majority of charge controllers are designed to work on both 12V & 24V battery systems; they will automatically detect whether your battery configuration is 12V or 24V. We also stock a small range of MPPT solar charge controllers that are capable of work on 36V & 48V battery systems.

Each manufacturers charge controllers may differ slightly in what their capabilities are, in terms of Voltage & Watts input and along with the amounts of Amps they can handle.

When choosing your solar charge controller, make sure it is compatible with your battery i.e. standard sealed lead acid leisure battery, AGM, GEL or even Lithium. The majority of standard PWM and MPPT solar charge controllers we sell are capable of running the above battery types but not lithium.

If you are running a 24V battery systems (2 x 12V battery connected together in series), you can usually double the input of the solar panel input. However please be aware to check the maximum voltage input of the solar charge controller, to make sure you do not overload it.

The charge controller you require will depend on the number and type of panels you wish to run.


Charge controller recommended (when you have a 12V battery)

Design notes

100W Ulica panel

10A charge controller

12V systems

150W Ulica panel

20A charge controller

12V systems

250W Ulica panel

20A MPPT charger

12V systems




Using your own panels?



12V panel rated up to 120W

10A charge controller PWM

240W for 24V systems

12V panel rated up to 240W

20A charge controller PWM

480W for 24V systems

30V panel rated up to 300W

30A MPPT charger





Installing more panels?



2 x 100W Ulica panels

20A charge controller

Connect the panels in parallel

2 x 150W Ulica panels

30A charge controller

Connect the panels in parallel

2 x 250W Ulica panels

40A MPPT charger

Connect the panels in series or parallel