A battery can also fail – The most common defect is a dead cell. The Battery Life Saver™ electronic device will not help a battery or batteries that have an open or shorted cell. Larger devices and appliances may run on batteries or battery packs that put out 12-24 volts. So next I did a volt test, battery 1 – 6.1v 2 -6.33v 3- 6.03v 4-6.33v 5 & 6 – 6.0v each. This should be very easy. I then did a total volt test across all 6 batteries and got 37.35. The correct fully charged specific gravity of your 6-volt deep cycle battery is: 1.265 (will vary dependent on battery age, condition and ambient temperature) Battery life is directly related to keeping your batteries fully charged. First, find the positive and negative terminal on the battery. A dead cell means that the connection between one of the cells on the inside has been broken. Take a battery or battery pack that's compatible to your battery charger. With Lifeline batteries a dead cell is very uncommon but not impossible. A parallel RV battery bank increases the current but allows the voltage to stay the same. This creates a negative negative and a positive positive. For reference, a standard lithium ion battery is rated for around 4 volts of electricity. Measure the voltage of each battery. In order to tell if a battery as an open or shorted cell, simply perform the following tests. Take the black test probe and place it on the negative side of the battery. Then, take the black lead and place it on the negative terminal of the battery. Make sure the battery has no corrosion and is not leaking fluid. Touch the positive end of the battery with the red probe. a.) We hooked up a simple 12-volt halogen light to the terminals on the battery along with our meter to monitor the voltage drop. If the battery voltage spread exceeds .15 volts for a 6-volt battery, or .22 volts for a 12-volt battery a problem is indicated. Battery voltage alone does not confirm a problem. Allow each battery in the system to stand on open-circuit for about one hour. 10.5V is a destroyed battery for a normal (not deep-cycle) automotive battery. Flashlights that hold a 6-volt battery are larger than ones you can grip with one hand and they have handles for easy carrying. If your battery charger tests well below the recommended output, it may be time to invest in a new one. In a car 12V is dead, a “12V” lead-acid battery should be above 12.5V at rest. Well I still didnt believe what I was seeing, so I did a draw test on all 6 bateries and the voltage dropped to 24 volts within 10 seconds. However, a dead battery makes the flashlight useless, and fumbling around in the dark is not the best way to replace a battery. Parallel connections are done by connecting two positive terminals to two negative terminals. Next, take the red lead of the voltmeter and place it on the positive terminal. If you join two 6-volt RV batteries in parallel, you will get 6 volts, but the amps will now be increased. Use a temperature compensating battery hydrometer for this test. Okay, here’s how you test the battery. How to Test for a Bad Battery. Example: If a 6 volt battery is reading below 4.3 volts it has a short cell . If your battery has a dead cell it will not register any higher than 10.5 volts. Running cars have alternator voltage regulators set between 13.5 and 16V. Step 3. Today we are taking a look at the TT TOPDON AB101 Automotive Battery Tester. Step 4: Testing for an Open Cell in a Flooded/Wet cell battery. A flashlight is one of the first things we look for when there is a power failure. Using a voltmeter will only tell us if the battery is bad. You will need a voltmeter and a hydrometer to perform both of these tests. Batteries are more resistant to degradation and freezing when they are … If you have the sealed type batteries, this test method cannot be used.