PWM5 Solar Charge Controller
Thank you for buying the PWM5 Solar Charge Controller from 256.co.uk – this guide will help you get the most from the product.
The PWM5 is a 6 amp solar charge controller using pulse width modulation for precise voltage control. Designed to be connected between a solar panel (up to 100 watts) and 12 volt lead-acid battery, the PWM5 ensures maximum battery life by preventing overcharging and maintaining maximum possible state of charge. The 3-stage charge sequence ensures that electrolyte is regularly mixed and acid stratification is minimised. Power consumption of the PWM5 is extremely low so more power ends up in the battery. The LED can be disabled if desired for even lower power usage.
- Pulse width modulation charge control system
- Solid-state microcontroller and MOSFET circuit
- 3-stage charge sequence for safe rapid charging
- LED voltmeter (0.1V accuracy) and PWM indicator
- For use with 12 volt lead-acid battery systems
- 6 amps maximum current handling
- Compatible with solar panels up to 100 watts
- Multiple controllers can be used in interesting configurations
- Intelligent co-operation with grid tie inverter
- Extremely low self consumption (less than 1mA)
- Protected against short circuit and reverse polarity
- Very low emission of radio frequency interference
- 100% waterproof
- UK designed, manufactured and supported
The red and black wires should be connected to a 12 volt lead-acid battery – red to positive, black to negative. Keep the battery connections as short as possible, ideally attach battery clamps directly to the ends of the red and black wires. For safety, an 8-amp fuse should be connected into the red wire.
The yellow and black wires should be connected to a 12 volt (nominal) solar panel – yellow to positive, black to negative. The solar panel cables can be extended, but keeping them as short as possible will minimise power loss.
Please note – The PWM5′s two black wires are connected together internally.
Upon connection, the charge controller’s blue LED will light for 2 seconds then extinguish. If the charge controller is disconnected during this 2 second period, LED operation will be disabled when next connected. This reduces the controller’s current consumption below the 1mA average (to around 650uA). To re-activate LED operation, disconnect the charge controller from the battery at any time other than during the 2 second period.
Please note – disconnect the battery clamps at dawn, dusk or when skies are overcast. There could be some pretty big sparks if you disconnect during full sun!
Bulk Charge (LED voltmeter)
During bulk charge, the LED indicates battery voltage – slow flashes for volts and faster flashes for tenths of a volt. Volts are displayed with 10 subtracted to make counting easier (you must add ten volts to determine the actual battery voltage). Tenths of a volt are displayed in full (up to 9 rapid flashes). It may not be possible to determine the exact number of rapid flashes.
Saturation/Float Charge (LED PWM indicator)
During saturation and float charge, the LED indicates PWM operation. The brightness of the LED indicates the amount of surplus energy. If the LED is bright, the battery is more fully charged. There is a perceptible flicker of the LED during PWM operation to indicate pulse width modulation.
During the saturation charge phase, the charge controller will hold the battery at 14.4 volts. After a period of time, the PWM5 will switch to the float charge phase and hold the battery at 13.5 volts. Overnight, the controller switches back to saturation charge mode to ensure the battery is charged as fully as possible, early the next day.
Low battery Indication
If the battery voltage is low (below 11 volts), the LED will pulse at a regular rate. This indicates that the battery requires charging. Additional charging (using a battery charger) may be required during winter months.
Extending the 6A Limit
Multiple charge controllers can be used to connect multiple solar panels to a single battery. Each PWM5 can have a solar panel up to 100W connected to its yellow/black wires. Then all the red/black wires are connected in parallel and hooked up to the same battery.
Charging 2 (or more) Batteries with 1 Solar Panel
Multiple charge controllers can be used to charge more than one battery from just one solar panel. This time a single solar panel up to 100W is connected to the yellow/black wires of multiple PWM5s (in parallel). The controllers’ red/black wires go to the batteries (one controller per battery).
Compatibility with Grid Tie Inverters
If you have a grid tie inverter (the type that operates between 14 and 28 volts), you can connect both your solar panel (up to 100W) and the grid tie inverter to the yellow/black wires of the PWM5. The red/black wires connect to your battery. In this configuration, your battery will be charged first, then surplus power from the solar panel will be drawn by the inverter and fed into your mains. The best of both worlds – a fully charged battery and solar power offsetting your electricity usage and lowering your bill!
Please note – you can connect the yellow side of multiple PWM5s together or the red side, but not both. Controllers cannot be paralleled up. Solar panels larger than 100 watts cannot be used with this controller.
The controller is protected against short circuit and reverse polarity at both the battery and solar panel connections.
The PWM5 is also protected against interference from radio transmissions and electrical activity. A watchdog circuit ensures its continued reliable operation. Radio frequency emissions are extremely low.
A diode is fitted into the yellow wire. This protects the charge controller against short circuit and should not be removed during the warranty period. If product warranty is not required, the diode can be removed for a small performance improvement. If the diode is removed, ensure that your solar panel is fitted with a blocking diode and that the solar panel connections are not shorted when the controller is hooked up to a battery.
Please note – never short circuit the terminals of a lead-acid battery.
The PWM5 comes with a 1 year warranty. The warranty will be void if the diode is removed from the yellow wire, or more than 6 amps are passed through the controller. Solar panels larger than 100 watts cannot be used with this controller.
Problem: The LED has stopped working and disconnecting the battery hasn’t fixed it.
Solution: This can happen when there’s power coming from the solar panel. Cover the solar panel and try disconnecting the battery again. Or wait until dark and disconnect the battery. The LED function will be restored.
Problem: My panel is connected but there’s no output.
Solution: Connect the red/black wires to a 12 volt lead-acid battery.
Detailed Explanation: The charge controller does not work like a voltage regulator. If you connect a solar panel to the yellow/black leads, you will measure nothing on the red/black leads unless they are connected to a battery. In fact the only meaningful voltage measurements you can make are at the battery terminals.
- Maximum current handling: 6 amps
- Maximum solar panel power: 100 watts
- Current consumption (LED indicating voltage): 1mA average
- Current consumption (LED off): 650uA typical
- Dimensions: 68mm x 35mm x 17mm (approx)
- Cable lengths: 220mm (approx)