SunGuard 4.5A Solar Charge Controller


A Solar charge controller (aka solar charge regulator) is a device which manages the current flowing into and out of the battery bank of a solar power system.

The SunGuard range of solar charge controllers are manufactured by MorningStar Corporation of the USA who sell some of the world’s leading solar controllers and inverters. The unit itself is manufactured in Singapore.

SunGuard 4.5 Amp Solar Charge Controller

SunGuard 4.5 Amp Solar Charger Controller

The SunGuard 4.5A Solar Charge Controller is the most technologically advanced, economical, small solar charge controller available on the market. It is fully weatherproof and rated for inputs of up to 4.5 Amps from 12V solar panels making it ideal for solar power systems rated at up to 60 Watts.

Prices start from around US$30 in the USA and £20 in the United Kingdom from a wide range of RE system suppliers.

Installing the SunGuard Solar Controller

Installing a SunGuard Solar Charge Controller

Installing a SunGuard Solar Charge Controller in a PV solar system is very simple. On the front of the unit the four wire input/outputs are labelled very clearly. One each for the positive and negative inputs from the solar panel(s), and one each for the positive and negative outputs to the battery / battery bank.

To protect against overloading the charge controller a 5 Amp Fuse should be connected in the positive lead from the solar panel.

When using a solar charge controller such as this it is not necessary to use a blocking diode to prevent batteries draining through the solar panel at night. The SunGuard 4.5A Charge Controller has integrated reverse current protection (<10mA reverse current leakage).

SunGuard 4.5A Specifications

Rated Solar Input: 4.5 Amps constant (5.5 Amps for no more than 5 minutes).
System Voltage: 12 Volts.
Charging Mechanism: Series PWM (pulse width modulation) with temperature compensation.
Regulation Voltage: 14.1 Volts (not adjustable).
Max. Solar Voltage: 30 Volts.
Reverse Current Leakage: <10mA.
Weight: 90 grams.
Dimensions: 2.5 x 2 x 1.5 inches.
Wire size: 16 AWG (2mm2).
Operating Temperature: -40 to 85 degrees Celcius.

– The SunGuard 4.5 Amp solar charge controller is full encapsulated in an outdoor rated ABS plastic case, and all circuitry is protected from the elements by epoxy potting. Any water which gets into the case will simply drain out and will not affect the electronic components.
– Just 6 mA are consumed by the SunGuard 4.5A controller.
– All specifications are rated for 25% overloads.
– The controller compensates for ambient temperature – for example, at 0 degrees Celcius the regulation voltage is increased to 14.8V.

The full SunGuard 4.5A Solar Charge Controller specification sheet (PDF) can be downloaded here.
The SunGuard 4.5A operator’s manual (also PDF) can be downloaded here.

Buy a SunGuard 4.5A Charge Controller in the UK

NEW – We have limited supplies of the SunGuard Solar Controller available in the REUK Shop at just £19.99 plus £1.95 postage. We also have other solar charge controllers in stock.


A wide range of MorningStar Solar Regulators are also available in the UK from Midsummer Energy (midsummerenergy.co.uk). Click here to view their MorningStar Solar Regulators web page.

Midsummer offer the SunGuard 4.5A solar regulator at £26 with a £4 delivery charge. Also available are the SunSaver 6A and 10A models (with or without automatic low voltage disconnect) from £40-£59, and the ProStar 15A and 30A models which are priced at £95 and £125 respectively.