Looking after a solar kit
We've compiled some hints and tips to help you install and maintain your solar kit:-
1) Solar Charge Controllers
A common mistake when connecting up a solar charge controller is the order in which you attach things. Always connect the battery first. This gives the solar panel charge controller a chance to analyse the battery voltage before any external influences effect it (Inverters and solar panels) After connecting the battery(s) you should connect the solar panels.
Never connect an inverter to the output of a charge controller even if it's off. Most inverters have large capacitors that will pull a large current to charge them. This large current will likely damage the charge controller in your solar kit.
If you look after your batteries they will last years if you don't they will last months!
Batteries need to be fully charged on a regular basis. If they aren't then they degrade rapidly. During the normal discharge and recharging of solar batteries the lead plates contained in them shed and collect sulphur. If the sulphur remains on the plates too long it hardens and won't come off during the charging process. Hardened sulphur reduces the storage capacity of your batteries. Under some circumstances it is possible to use a controlled charging method to remove sulphur that hasn't hardened too much. Contact the battery manufacturer for information on how to do this.
Charge controllers have an option to perform what's know as an equalisation cycle. This cycle must performed to stop the acid stratifying in the batteries and helps prevent the build up of sulphur on the lead plates. Make sure your inverter/charger or solar charger is performing this function on a regular basis. Some batteries used to have a tube that could be attached to a small pump for bubbling air in the acid. This was quite an affective way of agitating the acid to prevent stratification.
3) Solar Panels
When calculating the maximum output of your solar panels make sure you take the temperature coefficient into consideration. The VOC (Voltage open circuit) of solar panels is given at +25Deg C. the VOC at -10 on a cold, frosty morning can be as much as 5 Volts more. Don't blow up the charge controller in your solar kit by connecting it to solar panels that exceed it's maximum input VOC. Some solar charge controllers have protection against over voltage but others don't. Make sure you check the maximum input voltage for your charge controller.
Most inverters have three power ratings. Continuous , short period and surge. The continuous value refers to the amount of power the inverter can supply all the time without any problems. The short period is generally a little more to cope with peak requirements over a 20 min period. The surge is available for a second or so to provide additional power for starting pumps etc. The surge power can be as much at three times the continuous rating. Always check the manual for your inverter.
We often get asked what the difference is between pure sine and modified sine wave inverters. An inverter with a modified sine output (or anything else that isn't pure sine wave) can damage electronic equipment. We only stock and sell pure sine wave inverters. In our experience it isn't worth the risk.