DC 7–40V Battery Level Indicator & Voltmeter Module

Compact open-frame battery monitor that shows live pack voltage and a five-step, voltage-derived charge-level estimate. The numeric display helps you check system voltage at a glance. The bar display is an estimate based on voltage; it does not count amp-hours or watt-hours and is not a coulomb counter. Load, charging state, temperature, battery age, and chemistry can all affect the indicated level. Received display-color options Blue Green Red Each selection includes one indicator module in the chosen display color. Electrical limit Supplier-stated input range DC 7–40V Connection points Board pads marked VCC and GND Display Digital voltage reading plus five charge-level segments Use the battery’s highest possible charged voltage—not only its nominal label—to confirm compatibility. A battery described as “36V” or “48V” may exceed 40V when fully charged, so those nominal labels do not establish safe compatibility. Similar-looking revisions are sold with different voltage limits by display color. DIY500AMP applies the conservative 40V maximum to every received color unless that exact unit is independently verified. Installation and verification Disconnect the battery and confirm the pack’s maximum charged voltage is within the stated range. Connect VCC to battery positive and GND to battery negative with correctly rated, insulated wiring and appropriate branch-circuit protection. Verify polarity before applying power. Reverse polarity or overvoltage can damage the module. Compare the displayed voltage with a trusted meter at several operating points before permanent installation. Treat the bar display as a relative guide until its full-to-empty behavior has been checked with your specific chemistry and pack. Indicator only. This module is not a charger, BMS, cell balancer, fuse, low-voltage disconnect, or other safety device. The board is open-frame and is not advertised as waterproof. Mount it where the electronics and connections are protected from shorts, conductive debris, moisture, vibration, and strain. Ships from DIY500AMP.COM in Florida when in stock.