Battery Monitors
Overview
Overview
Battery Monitors Overview
About Battery Monitors
About Battery Monitors
Voltage tells you almost nothing about a battery. A monitor tells you what is actually in it.
A lithium battery sits at nearly the same voltage from full to almost empty, which is one of its strengths and one of its traps. Read the voltmeter and it says fine. Read it an hour later and it still says fine. Then the fridge stops. An AGM is a little more honest, but only after it has been resting for hours, which it never has.
A battery monitor solves that by counting rather than guessing. A shunt sits in the negative lead and measures every amp that goes in and every amp that comes out. The monitor keeps the tally and turns it into a percentage, a time remaining, and a history. It is the fuel gauge the battery never came with.
The range runs from simple displays with a shunt through to Bluetooth units that put the whole picture on a phone, and complete power systems with the monitor already built in. Remote displays for chargers sit here too, for installs where the charger is out of sight and its status needs to be somewhere you can see it. A monitor that shows a percentage on the wall by the door gets looked at ten times a day. One buried in a cupboard gets looked at when something has already gone wrong.
Fit the shunt on the negative side, with nothing else connected to the battery's negative post. Every load and every charger goes through it, or the count is wrong from the first day.




