#Digital 12 volt battery meter full

You aren’t maintaining multi-million-dollar military defense systems, so you can handle a bit of estimation – and don’t have a choice, really! Measuring Voltage:

#Digital 12 volt battery meter full

Knowing that you can’t accurately measure how full they are without some rather inconvenient steps, you can change your mindset to keeping the batteries “ good enough”. The main goal of a battery monitor is to help keep your batteries healthy. Let’s step back here and look at the big picture. After that time, you need to re-set the batteries like discussed before: disconnecting them and letting them sit for 24 hours after a proper full charge. They might be relatively accurate after 3 days or a week, but they’re still not going to give you a very good picture of how “full” your batteries are after constant use. But in the end, this is just delaying the inevitable inaccuracy. Some have temperature sensors and can be programmed for specific chemistries of batteries. More expensive battery monitors do take some of these variables into account. But the size of the container changes with temperature and how fast you’re pouring, and you don’t know how much you’re spilling, but you are sure you’re spilling a little bit. So trying to total the number of Amps being absorbed when you don’t know how efficiently they are being absorbed is nearly impossible.Īgain, this isn’t much different than trying to measure how much water is coming out of a container using measuring cups.

The reason is that lead acid batteries’ efficiency varies due to things like temperature, size, discharge rate, age, etc. Most battery monitor systems lose their accuracy and utility after a short period of time. Where this method breaks down is that while it’s relatively easy to measure Amps going through a system at any given instant, trying to count those Amps over a period of time is difficult to do with lead acid batteries. Measuring Batteries Doesn’t Sound too Bad, Right? This is the basic theory for most battery monitors you see on market. For instance, if you have a 100Ah battery and your battery monitor measures 25Ah taken out, then you would know that you have 75Ah left in that battery. This lets the internal cells balance out properly, assuming they’re all in good condition.Īfter that’s done, you measure the Amps that are put in and taken out over a period of time to know how Amp-hours are in your battery. To be sure the battery is 100% full, you need to give it a 3-stage charge and let it sit for 12-24 hours without being used. This is similar to counting how many cups of water are being poured out of a full container to know when it’ll be empty. The next logical step is to fill the battery all the way up as a starting point, then keep track of how many Amp-hours are used to know how full your battery is at any point in time. That scenario isn’t common though, so let’s look at it when you’re in control of more variables. You’d need to be able to let it sit for 12 hours to balance and level out as well as have a machine that can load test it or use a hydrometer if you’re lucky enough to be handed an FLA battery. There isn’t a measurement that you can take to that can tell you this. If you were handed a lead acid battery off the street, it would be quite difficult to tell how “full” it is on the spot. Let’s first look at what can’t be measured realistically from a battery.