How do I know my battery is going bad?

Your average battery seldom reaches its life expectancy. In fact only about 30% of the batteries sold today reach the 48th month mark. This is often due to poor maintenance and use. Think of SLA batteries as a children’s piggy bank – if all you do is take money out, without putting any in, chances are you will be broke very soon. It is very important to charge your batteries immediately after discharge. Do not put off recharging them! Another good thing to remember is that batteries are actually not some kind of reservoir of electricity. They actually produce the electricity via chemical reactions occurring inside them. So it is very likely that the problem with your battery is chemical.

Inspect your battery

It is often easy to understand that your battery is bad by a simple visual inspection. When inspecting the battery pay close attention for broken terminals. They can be very dangerous as they can cause a short circuit to occur leading to possible explosion. Also look for bumps and cracks. Bumps are sometimes due to overcharging and cracks in case are often caused by mishandling.

Measure the voltage in idle

A good way to diagnose your battery is to measure its voltage.You can do so with a digital voltmeter. If fully charged a 12 volt battery should read about 12.65 volts. A reading of 12.4 – 12.45 equals about 75% charge. Anything less means the battery is sulfated. Sulfation is a natural process in batteries during discharge. When recharging the process is reversed. If the battery was discharged for long periods however, the sulfation crystals will harden on the battery plates. This hinders the full charge capacity and makes the battery discharge quicker.

Measure the voltage during load

The next step is to do a load test. You can do it yourself or ask your local car shop. You will need a digital voltmeter and a fully charged battery. If you do the test on a motorcycle battery you will need to remove the seat, expose the battery (check out how to do this) and hold the prongs of your voltmeter to the battery terminals. Now push the starter button and take the voltage reading.

A 12 volt motorcycle battery in a good state should be able to maintain 9.5 – 10.5 volts for 30 seconds. If it steadily drops in voltage or instantly drop to zero – we have a problem. In the later case we are often talking about a so called open cell. This problem can be caused by the dreaded sulfation buildup or can be due to manufacturing flaws. It occurs when a weld piece connecting the cells comes loose due to the heat of the load and cuts the current. When the battery is cool the pieces will not be separated and your voltage reading will seem normal, so this problem will be visible only under load.

If your battery has any of the symptoms described above then maybe it’s a good idea to buy a new one. At BatterySharks we carry a wide variety of batteries including AGM and Gel batteries used to power motorcycles, UPS devices, wheelchairs and scooters, alarm systems and many more.