How to Choose Battery for 500KW Diesel Generator Set

Battery is one of the important components of 500kw diesel generator set. Before we choose battery, we should know first its function in diesel generator set.

What is function of battery for diesel generator set?

1.The battery is mainly used to start the diesel engine. There are one or more starting motors on the side of the diesel engine. They use DC 24 V (some small diesel generator sets will use DC 12V) to drive the starting motor to start the diesel engine.

2.To monitor the power supply, which is the power frequency alternating current (AC). The frequency of AC power is 50Hz and 60Hz, which is commonly used in various countries in the world. The distribution of civil AC voltage varies from 100 V to 380 V, and the domestic genset room generally use three-phase 380V) and the conditions of diesel oil, engine oil and coolant should meet the starting requirements before starting the diesel engine.

3.It is used for excitation (some types of diesel engines need to be excited after starting).

What are types of commonly used battery?

1. Maintenance free battery

Due to the advantages of its own structure, the consumption of electrolyte of maintenance free battery is very small, so It is not necessary to add distilled water within the service life. It also has the characteristics of shock resistance, high temperature resistance, small volume and small self discharge. The service life of the battery is generally twice that of the ordinary battery. There are also two kinds of maintenance free batteries on the market: the first one is to add electrolyte at the time of purchase, and then there is no need to maintain it when using; the other is that the battery itself has been added with electrolyte and sealed when it leaves the factory, so the user can't add the supplementary liquid at all.

2. Ordinary battery 

The plate of ordinary battery is composed of lead and lead oxide, and the electrolyte is an aqueous solution of sulfuric acid. Its main advantages are stable voltage and low price, while its disadvantages are low specific energy (i.e. the energy stored in per kilogram battery), short service life and frequent routine maintenance.

3.Dry charged battery

Its full name is dry-type charged lead-acid battery. Its main feature is that the negative plate has a high storage capacity. In a completely dry state, it can keep the electricity obtained within two years. When using, it only needs to add electrolyte and wait for 20-30 minutes to use.

4. Wet charged battery

A battery in which the plates are charged with a small amount of electrolyte, and most of the electrolyte is sucked into the separators and plates for storage.

Which type of battery is better?

Due to the maintenance free battery in normal use conditions, there is no need to add electrolyte in the process of use. The self discharge is only 1/8~1/6 of that of ordinary battery, so it can be stored in wet condition for a long time. The internal resistance is small and has good starting performance at room temperature and low temperature. Under the same charging voltage and temperature, the overcharge current of the maintenance free battery is smaller than that of the ordinary lead-acid battery, and the current is close to zero after full charge, which basically does not volatilize water and consumes little electrolytic water. There is no corrosion or slight corrosion of the battery pole. Heat resistance, good vibration resistance, long service life, generally more than 4 years, more than 2 times the service life of ordinary batteries. Therefore, at present, the manufacturers of diesel generator sets recommend customers to choose maintenance free batteries.

How to choose size of battery?

First of all, the battery has two important indicators, which are starting capacity index (CCA) unit ampere (A) and capacity index (C20) unit ampere hour (AH). Starting ability index, that is, under certain conditions, the starting current measured at low temperature starting current for 30 seconds and the battery voltage above 7.2V, reflects the performance of the battery. Capacity index, that is, the time taken for the set current to discharge continuously from full state to 10.5V, reflects the storage capacity of the battery.

We should select the battery for diesel generators according to the starting current (CCA), not according to the capacity (AH). Diesel generator set is different from vehicle, because the main function of battery for diesel generator set is to ensure reliable starting. Therefore, the starting performance (CCA) value is the most important indicator of the battery for diesel generator set. The larger the starting performance (CCA) value is, the stronger the starting performance of the battery is. For example, Chongqing Cummins K38 series diesel engine only specifies the starting current (CCA) value of the battery required by the starting motor in different temperature ranges in its technical documents, but does not require the capacity (AH) of the battery.

After you read this article, maybe you have known how to choose batteries for diesel generator set. If you sill have questions, maybe you can contact us, we will answer for you. Our factory diesel generator set is usually equipped with maintenance free batteries with battery charging line. Because maintenance free batteries are better than other types batteries. If you have purchase plan of diesel generator set, welcome to send us inquiry with your main specifications, we will send you price and technical specifications. We believe we can supply good product to you with our 43 years’ experiences.