December 2022

How Many Volts to Start a Diesel Engine

It’s winter time, and that may mean your battery is on its last legs. If you’re shopping for a new battery for your diesel, you may be wondering how many volts it takes to start a diesel engine. 

Read our guide on everything you need to know about diesel batteries, and how many volts it takes to start a diesel engine.

How Many Volts for a Diesel Engine Battery

The best diesel engine batteries are 12 volt batteries. When starting a diesel engine, it is typical for a battery to have less than 12 volts, but then get up to closer to 14 volts and above when the engine has warmed. Diesel engines require a 12 volt starter that is able to spontaneously combust and get the engine running. That’s why even though diesel engines require 12 volt starters, they run on two 12 volt batteries that work in tandem to ensure that the starter has the juice to get the engine running. 

Can You Run a Diesel with One Battery

Most diesel engines have two batteries that are connected in parallel. Even though you need 12 volts to start a diesel engine and each diesel battery would be a 12 volt battery, it’s not recommended to run a diesel on a single battery. This is because along with needing voltage to start, diesel engines require a higher cranking amperage than gas powered engines. So although you can definitely start a diesel engine with a single 12 volt battery, you won’t be able to run the engine effectively for very long. 

Furthermore, if one of your batteries dies, it’s important to replace both. When batteries are running in parallel, it’s important that they are the same age, type, and size. This is because the size, type, and age of a battery all relate to its amperage and how current will be distributed through the engine. If the batteries aren’t working the same, it can cause issues with your engine.

Difference Between Voltage and Amperage

Volts and amperes are completely different measurements regarding electricity. A volt is a unit of electrical potential, or the size of force that would send electrons through a circuit. Amperes, on the other hand, measure electrical current and how many electrons are flowing through a circuit. Regarding diesel engines, the battery voltage is the amount of force it takes to get the engine started, whereas amperes are how much electricity is flowing through the engine when it’s running. 

Best Diesel Engine Batteries

There are plenty of diesel batteries to choose from, so we’ve compiled a list of three diesel engines that we would recommend. 

1. XS Power D3400 XS Series 12V AGM High Output Battery

This battery has a tight seal and fiberglass layers to prevent spilling and limit vibration. This battery is also incredibly powerful in the cold, making it a great choice for climates with long winters like Alberta. It can deliver steady power in frigid temperatures as well as has a fast recharge time, making it a great choice for your diesel.

2. ACDelco 94RAGM Professional AGM Automotive BCI Group 94R Battery

This battery contains high-density negative paste to increase performance as well as the batteries overall lifespan. Its vent cap design reduces acid leakage risk, and it runs great in the cold weather with 800 cold cranking amperage. With solid specs and efficient performance, it’s an ideal choice for many diesel owners. 

3. Optima Batteries 8004-003 34/78 RedTop Starting Battery

Optima batteries are a fantastic choice, and the RedTop ensures 800 cold cranking amps for those frigid winter mornings, plus it has a strong casing that gives the battery more resistance to vibration, making it incredibly durable. You can definitely trust that this battery will do its job with your diesel.

We Know Diesels

DFC Diesel are your Dodge, Fod, and Chevy diesel engine experts. Our specialized team remanufactures and refurbishes diesel engines to make them as good as new. If you have questions about your diesel or want to get started working with DFC, please contact us!