Use these battery gauges to monitor your batteries.
Permanent Battery Gauges work with any 12-volt lead-acid battery. Internally lit for day or night use, they are easy to mount and include step-by-step instructions. In-dash single gauge requires 2" to 2-1/16" diameter hole. Available: Single-Battery Gauge, Two-Battery Gauge, Four-Battery Gauge.
The Handheld Portable Battery Gauge fits easily in a toolbox or tackle box and includes probes for testing battery charge without complicated wiring. Works with any standard 12-volt lead-acid battery.