Understanding Battery Specifications
Understanding Yuasa Battery Codes and Performance
When you're choosing a battery, you'll see a few different numbers. Here's a quick guide to what they all mean, especially for the UK market.
Part Numbers: Finding the Right Fit
Yuasa Number (UK Standard)
Yuasa part numbers are based on the BBMS (British Battery Manufacturers Society) standard. This has been the widely used and well-understood code system in the UK aftermarket for many years, making it the most familiar to local businesses and customers.
ETN (European Type Number)
The ETN is the modern European standard, replacing the older DIN (German Industrial Standard) number.
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It's a 9-digit code (e.g., 536 046 030) that combines the older DIN system with extra technical details.
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The first digit tells you the voltage: 5 to 7 means it's a 12-volt battery.
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The second and third digits relate to the battery's nominal capacity (e.g., 560 means 60 Ampere-hours (Ah) at the 20-hour rate).
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The rest of the digits detail the battery's specific features, performance, and cold-cranking rating.
A quick heads-up: Because the ETN system led to thousands of new numbers, cross-referencing can be tricky without formal records. This is one reason why many UK businesses still rely on the familiar Yuasa/BBMS codes.
Performance Ratings: How Well It Starts and Lasts
Cold Cranking Performance (CCA)
This is the most important rating for starting your car. The CCA measures the battery's starting power at a cold temperature (-18^\circ C).
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Simply put: the higher the CCA, the easier your vehicle will start.
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Yuasa typically uses the SAE (American Standard) CCA rating as the norm. We find it gives a clear, balanced view of both the initial starting power and how long that power lasts (starting endurance).
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Please note: According to EU regulations (EU1103:2010), batteries must also display the 20 hour capacity (Ah) and the EN1 CCA rating.
Reserve Capacity (RC) in Minutes
The Reserve Capacity tells you how long, in minutes, your vehicle could run if your alternator or fan-belt were to break.
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This is the time a fully charged battery can continuously power a typical electrical load (25 Amps) before its voltage drops too low.
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It's a great practical test to show the battery's endurance.
Ampere-Hour Capacity (Ah) at 20 Hour Rate
The Ah capacity measures the total amount of electricity stored in the battery.
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This is calculated by seeing how much current the battery can deliver over 20 hours until the voltage drops.
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For example: A 60Ah battery will deliver a current of 3A for 20 hours (3A times 20h = 60Ah).
Where to Find Specific Details
Looking for technical specifics like terminal type, cell layout, or dimensions?
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Dimensions (Length, Width, Height): These are always in millimetres (mm) and include any parts that stick out, like terminals or hold-downs. Weight with Acid (kg) is the average supplied weight.
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Layout and Features: You'll find diagrams for the Cell Layout, Terminal type, Container Features (e.g., hold-downs), and Handles in the 'diagrams' or 'technical specification' tabs on each Yuasa product page.
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End-Venting: Some modern batteries now have a vent at the negative end for remote venting, which is handy for some vehicle setups. You'll find this detail in the 'technical specification' tab.
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State of Charge Indicator: This is a simple visual tool (a floating ball/prism) on one cell that gives you a quick check of the charge level and electrolyte within the battery.
A Note on Battery Match-Ups
Our GS Yuasa Automotive Online Battery Look Up Tool aims to give you the most accurate match possible between your vehicle's Original Equipment (OE) battery and our range.
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You might notice tiny differences in the CCA or Ah ratings between the OE part and our replacement. Don't worry—these small variances won't harm your vehicle's electrical system.
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If you're having electrical error codes after fitting a new battery, it's highly likely they are residual codes caused by the old battery's failure and not by the new one.