A battery bank for an Off-Grid solar powered alternative energy system will consist of a number of batteries and their interconnecting terminal cables. The batteries will be connected together in various series-parallel configurations depending on your schematic design to achieve a desired voltage and capacity to work. How big should the cables be? First you will need to calculate the maximum current that could flow through the various interconnecting cables. The following maximumamps versus cable size (AWG) come from the NEC version 2011. As far as I know these values are valid as of today. For more detail though, check with the National. Eventually I decided to do-it-yourself for making heavy duty cables for my battery bank. I purchased bulk cable (just pick your size). And a heavy duty cable crimper (and the associated wire.
Choosing the correct size (diameter) and length of cable is important for overall e ciency. Cables that are too small or unnecessarily long will result in power loss and increased resistance. When connecting batteries in series, parallel or series/parallel the cables between each battery should be of equal length.
The battery cable size you need depends largely on the specific application requirements and current capacity. And the size is usually represented by AWG, which indicates the cross-sectional area. When determining the battery cable size, you should consider the following factors:
Wiring multiple batteries together as one big bank, rather than having individual banks makes them more e cient and ensures maximum service life. Wiring batteries together in series will increase the voltage while keeping the amp hour capacity the same.
How do I choose the right battery cable thickness?
There are ways to help you with selecting the correct cable thickness: Look in the product manual. The rule of thumb. Recommended battery cables table. All our manuals recommend the DC battery cable size (and fuse size) that needs to be used for the product. The Victron app helps you calculate cable size and voltage drop.
When connecting batteries in series, parallel or series/parallel the cables between each battery should be of equal length. As you can see in the diagrams below all the short cables connecting the batteries together are the same length and all the long cables are the same length.
The importance of batteries is self-evident, but people often overlook the role of battery cables. Whether in vehicles or other applications, they all require battery cables to transfer the power from the battery to connected devices.