Cabling should be proportionate to the amperage of your system. The following table notes the maximum current carrying capacity based on cable gauge. Battery cables should be selected allowing a maximum voltage drop of 2% or less across the entire length of the cable. Interconnection cables (battery to battery) should also be sized at the same gauge and of equal length between connections. When choosing interconnect cables or custom bus bars, size to allow adequate spacing between batteries for airflow as outlined above.
Wire gauge sizing by Amperage:
TERMINALS & CABLE CONNECTIONS
All cable connections should be adequately sized, insulated and free of damage. The cable connectors should be clean and properly mated with the battery terminals to ensure a snug connection.
Electrolyte spills and corrosion buildup will damage cable connectors and terminals. It is recommended that terminal connections are disconnected, cleaned and re-torqued periodically as part of the regular maintenance routine. This also applies to connections using bus bars. Check and recalibrate the torque wrench for accuracy before use.
Visual inspections may not always detect poor connections. The use of an Infrared (IR temperature) sensor may assist in identifying poor connections when testing under load or during charge. Connections that have overheated and/or developed problems will often be welded to the terminal. Loose connections may result in the ignition of hydrogen gas during charging or cause a short, melting of the terminals.
Loose or overtightened connections may also cause high resistance. The result is an unwanted voltage drop as well as excessive terminal heating which causes the terminal to melt or even catch fire. To limit the possibility of damage or fire, use a torque wrench to properly adjust terminal connections during your regular maintenance schedule.
As batteries are cycled and heat up during charge, under-torqued connections may become loose over time as the terminals heat & cool, causing possible arching and risk of spark. Over-torqued connections may indent, crack or bend the terminal and/or washers or terminal connectors.
Damage to terminals and/or batteries caused by under/over-torque is often unrepairable and is not covered under manufacturer warranty. Follow the recommended torque settings for each terminal type. Battery distributors or dealers may offer replacement or repair, where possible, at the customer's expense.