Battery charge indicators (BCI) are great simple gauges which measure battery voltage to provide an estimate to the user of how much range you have left. Range, as pertaining to an electric golf cart, is defined as the total distance you can travel on a single charge. They are fairly simple to install and I’ll discuss the installation and applications below.
There are two basic types of battery charge indicators commonly used in the golf cart and electric vehicle community. They are analog and digital (typically LED).
An analog gauge is a very simple, basic gauge which uses voltage to move a needle across a background indicator to reveal the state of charge. They appear very similar to a typical gas gauge on an automobile. The indicator background typically has an “E” for Empty to the far left and an “F” for Full to the far right. A digital gauge is generally an electronic device, usually with LED’s to display the same type of information. They usually have a series of LED’s which light up as the charge level changes. More LED bars indicate a greater level of charge, while fewer bars indicate less charge. Let’s discuss below how to install each type of gauge into an electric vehicle or electric golf cart.
• Analog Battery Charge Indicator:
Most analog battery charge indicators are very simple to install on a wide variety of electric golf carts. They normally have two power connection terminals per gauge. One is the negative and the other is positive connection. Specific details may vary slightly between manufacturers but the principles of installation will apply to all. The negative terminal of the BCI is connected to the main battery bank negative terminal (or the last negative in series of the bank). The positive terminal picks up the battery positive from the key switch rather
than directly from the battery. If you connect the positive lead directly, the gauge will pull a small amount of power all the time, regardless if the key is off or not. This could potentially drain your batteries during an extended leave. The positive lead should be connected to the “switched” side of the key switch. This is the terminal of your key switch which only has power when in the ON position. Wiring in this manner will turn the gauge off completely when the cart is not in use and the key is OFF.
• Digital (LED) Battery Charge Indicator:
The digital BCI’s are only slightly more difficult to install as they require one extra connection as opposed to an analog gauge. They typically have three terminals labeled 1, 2 & 4. Terminals 1 & 2 are connected directly to the main battery bank positive and negative, respectively. Yet, the gauge still will not light up, thus the need for the third connection. Terminal 4 is an additional positive needed to power the lights (LED’s) of the gauge. This extra positive picks up its positive feed from the “switched” side of the key switch as mentioned above. This will also cause it to power down and not draw current when the key is in the OFF position.
Click to view BCI DIAGRAM
By Michael Williams