The nickname for these lights are called "idiot" lights. I doubt they are very accurate, or they have a range value, so they are in the red, yellow, or green range.
Buy a good voltmeter, or better yet buy this. I think every RV should have one.
Trimetric 2025RV Battery System Monitor
06 Hurricane 34FT WH W20 Chassis 8.1L 120K, Steersafe, Koni Shocks, DIY Trac Bar, Tri-Metric 2025RV Battery Monitor, 4-6V Batteries, Scan Gauge 2, Crossfires, 735W Solar Morningstar MPPT-60, KVH R5 In-Motion Sat, XM Radio, 07 Chevy Malibu Maxx Toad, Falcon 2, Brake Buddy, Escapee