How to Select the Right Diesel Generator Battery?

Jun. 27, 2024

Batteries are an important part of diesel generator sets. Though an electrical generator can provide a backup electricity supply when the grid fails, it requires a battery to provide enough start-up power to turn on. A defective battery can result in generator failure. Read on and you will understand the function of diesel generator battery and learn how to choose the right battery for your generator.


Why does a diesel generator need batteries?

The battery is one of the essential components of a diesel generator set. It’s mainly used to provide reliable starting power for diesel engine in the generator set. There are one or more starter motor(s) on the side of the diesel engine that require batteries to offer the juice to get the engine running. Usually, diesel gensets have more than one battery as the engines are large and heavy, which require a lot of energy to turn over.

How to Select the Right Diesel Generator Battery?cid=4


Depending on the design of the engine, the battery may have other functions:

Activate the glow plugs to start the generator.

Activate fuel shut-off value.

Power any electrical or digital control panel the generator may have.

Power to monitor the utility power or whether the fuel, engine oil, coolant and other conditions meet the starting requirements before starting.

Power ancillary panes and small motors that operate on DC current and any DC supplied device within the enclosure.

Power the secondary or redundant batteries or genset (if any).

Power for excitation (Some diesel generators require excitation after starting).


Types of battery used in diesel generator sets


The lead-acid batteries are commonly used in diesel generator set. The can also be used in cars and trucks. Lead-acid batteries are the oldest type of rechargeable battery and typically less expensive than other types of batteries. Diesel generator lead-acid batteries are mainly divided into two categories: dry-charged batteries and maintenance-free batteries.


Dry-charged batteries

The main feature of dry-charged battery is that its negative plate has a high storage capacity. It can save the obtained electricity in two years in a completely dry condition. When needed, just add the electrolyte and wait for 20-30 minutes, they will work. Dry-charged batteries have the advantages of stable voltage and low price. The advantages are low specific energy (electric energy stored per kilogram of battery), short lifespan and frequent routine maintenance.


Maintenance-free batteries

Due to its own structural advantages, the electrolyte of free-maintenance battery is consumed in a small amount, and there is little need to supplement distilled water during the service life. It also has the characteristics of shock resistance, high temperature resistance, compact size and low self-discharge. Its service life is generally twice that of ordinary batteries. There are two types of maintenance-free batteries on the market. One type is that the battery is added electrolyte all at once when purchased and no maintenance (adding supplementary liquid) is required in use. The other is that the battery itself has been filled with electrolyte and sealed when it leaves the factory. Users can’t add supplementary liquid to the battery. Read more about advantages of using maintenance free battery.


How do I choose a diesel generator battery?


Choosing the right battery is vital to the proper operation of diesel generator set. Diesel generator set lead-acid batteries are available in 2.4 V, 4 V, 6 V, 8 V, 12 V and 24 V series, with capacities ranging from 200 MAH to 3000 MAH. Usually, the battery used in a diesel generator is 12V DC battery or 24V DC battery. The size of the battery is dictated by generator size and what components the battery needs to power.


To choose the right diesel generator battery, there are a few factors you need to consider:


Check diesel generator manufacturer specifications for the battery recommendations and choose the correct size battery for the application.

Consider the ambient conditions like high temperature or low temperature and make sure the battery is suitable for the application.

Compare the currently installed battery against the manufacturer specifications. Installed batteries that exceed manufacturer’s specs are acceptable.

Review data from research to insure accuracy and purchase.

Ensure the availability of the battery in your area.


Generally, a well-maintained high quality diesel generator battery can last for 3-5 year, depending on use, charging setup and application.


Need advice on diesel generator batteries? Contact Dingbo Power!


If you are not sure which type of battery is right for your diesel generator set, contact us today. Dingbo Power is a professional diesel generator manufacturer with over 17 years’ experience and we can help you choose the best battery for your generator. We are an authorized OEM supplier of diesel engines for generator sets including Cummins, Perkins, Deutz, Yuchai, SDEC, MTU, Ricardo, Volvo, etc. Feel free to contact us with any questions, concerns, or inquiries to learn more about the products & services we provide.

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