Battery Terminals

When using a battery or battery bank in a renewable energy system it is essential to ensure that all cables are fastened very securely to the terminal posts of the battery. If you look under the bonnet of a car at the battery you will see that the positive and negative cables of the electrical system are bolted to the battery using battery terminals. These should also always be used in renewable energy system battery banks.

Battery terminals bolted to a car battery

If for example a wind turbine is connected to a battery bank and one of the power cables disconnects from the battery, the wind turbine will spin faster and faster out of control. This is dangerous both to the turbine itself and to people, animals, and property nearby.

Battery Top Post Terminals

Pair of battery top post terminals

Pictured above is a pair of battery top post terminals (available on sale in the REUK Shop). These can be bolted onto the terminal posts of 12 Volt leisure, marine, and motor car batteries. The red terminal should be fixed to the positive post of the battery, and the black to the negative post. The cable which is to be connected to the battery is then sandwiched between two metal plates on the terminal and can be bolted safely and securely in place.

These battery terminals will accept cable up to 40mm2 in area – equivalent to a diameter of around 7.2mm corresponding to AWG 7. (click here to view our AWG wire size converter. The majority of battery terminals accept wire with a diameter of up to 8mm however battery terminals from lorries and other heavy vehicles can sometimes have a 10mm cable entry.

Zinc coated battery terminals

Where different colours are not used (see image above), battery terminals will be marked with an N for negative, and a P for positive as shown below.

Battery terminals marked with N and P