As you don't make 24 volt batteries can we use 12 volt instead. If so, how do we hook them up?

Yes you can use two 12 volt batteries by connecting them in series, as shown in the diagram below. Positive is connected to negative and negative is connected to positive. It is important that you access our Technical Manual page 17 for further information. To access our Technical Manual please visit the SLA Batteries section in our Datahub.