Solar Panels Batteries

 How long will it take to recharge my battery?

The time needed to fully recharge your battery with solar depends on 1) how much stored energy you need to replace in your battery/battery bank, 2) the efficiency of your solar regulator and the charging method it uses and 3) the amount of solar energy you can provide.  For the following example we will assume the regulator is 100% efficient.

Let’s say you need to replace 50A/h of stored energy into your battery via 300W of solar panels.

300W @ 12V = 300/12 = 25A

50A/h @ 25A = 50/25 = 2 hours

So as a rough estimate it would take around 2 hours to recharge your battery.  In a real life situation you would need to take into account the efficiency of your regulator and its ability to charge the battery to 100% (multi-stage charging), and the fact that the charger will output at least 13V to charge the battery (not 12V).

How do I connect my panel to my battery?

Your solar panels should always be connected through a regulator and then the regulator connected to the battery/s.  A regulator is required to ensure that none of the high voltages present at the output of a solar panel during good light level conditions can damage the battery/s.  Each panel/regulator comes with a set of instructions outlining how the panel/regulator should be connected to the system.  If after reading the instructions you are still unsure of how to connect your devices please contact a qualified auto-electrician or Redarc electronics on (08) 8322 4848.

What type of battery do I need for my solar setup?

The type of battery you choose depends on the application for which you are using it.  It is recommended that a deep cycle battery be used as an auxiliary battery because generally an auxiliary battery is discharged to a lower level and then recharged as opposed to a starter battery which is generally kept at a particular charge level. 

It is important to ensure that your regulator is designed to charge the type of battery you plan to install in your setup.  Most regulators will have specific charging profiles for the four different types of automotive batteries commonly used today. 

It is also important to consider where the battery is mounted.  If you plan to have the battery inside a caravan for example, you must get a sealed battery because an unsealed battery will generate harmful gases during charging.

Your best bet is to contact a battery supplier and discuss your requirements with them.