A dedicated section on starter batteries is essential because proper maintenance is crucial for starting the generator. If not maintained well, the generator won’t start.
Some diesel engines use compressed air as a starting choice, but this will be covered in a different section.
Today, starter batteries come in various types, brands, and models. For clarity, I will discuss two main types: sealed and unsealed. The unsealed type is often referred to as “with caps” and the sealed type as “without caps.”
Sealed batteries do not allow for checking the electrolyte level in individual cells. Nonetheless, some newer models have a small indicator. This indicator changes color to show the electrolyte level. You can check the battery’s health using external visual checks and electrical tests to see if it is still charged.
First, disconnect the static battery charger from the panel. Next, remove the two terminals from the battery poles. Use a tester to measure the no-load voltage. This voltage should not drop below the manufacturer’s lowest, which is usually above 12 V.
A specific tool can also help measure performance and give a report on the battery’s condition.
After testing, clean the battery poles thoroughly and reconnect the terminals, starting with the positive terminal, then the negative. Tighten the clamps firmly, but avoid damaging them, as they are soft metals. You can apply a protective spray on the pole, easily found in stores. Once you recharge the battery, check the terminal voltage and make sure the current is within acceptable limits. The correct voltage indicates proper operation, and the charging current should decrease gradually.
Now, regarding the batteries “with caps,” you should open them after wearing gloves, goggles, and a mask. Top off the electrolyte level with distilled water, specifically made for battery maintenance. A semi-automatic top-up tool can help, stopping automatically when the level is right. If you use a funnel, refer to the MIN and MAX lines on the battery. Remember, never add new acid; only distilled water. Adding acid can cause dangerous reactions with the charged electrodes.
Do not fill the battery if the caps show that the cells are dry. This dryness suggests poor maintenance, an overly charged battery, or a malfunction. Dry cells can overheat and generate gases, which can react dangerously with the distilled water you add.