Question 1

What is a battery code?

Accepted Answer

A battery code is an alphanumeric identifier printed on battery cells by manufacturers like CATL, REPT, and EVE. It encodes information about the manufacturer, battery chemistry (LFP, NMC), capacity, voltage, and production date.

Question 2

How do I read a battery production date code?

Accepted Answer

A battery production date code records the year and month a cell was manufactured, embedded within the full battery code. Paste the complete code into the Battery Days decoder and it extracts the production date automatically, along with the manufacturer, chemistry, capacity and voltage. For Chinese GB/T-standard cells the date is encoded positionally within the 24-character code, and the decoder handles that parsing for you.

Question 3

How do I decode a CATL battery code?

Accepted Answer

Enter your CATL battery code into the Battery Days decoder. The tool automatically identifies the manufacturer, extracts the product type, battery chemistry, capacity (Ah), voltage, and production date from the code structure. It also corrects common OCR scanning errors.

Question 4

Which battery manufacturers are supported?

Accepted Answer

Battery Days supports codes from major manufacturers including CATL, REPT, EVE Energy, Gotion, BYD, and others. The database is regularly updated as new manufacturers and code formats are added.

Question 5

Is the Battery Days API free to use?

Accepted Answer

Yes, the Battery Days REST API is free to use. You can decode battery codes programmatically via GET or POST requests. An embeddable widget is also available for integrating the decoder directly into your own website.

Question 6

What information can I get from a battery code?

Accepted Answer

A decoded battery code reveals the manufacturer name, battery chemistry (e.g., LFP, NMC), rated capacity in Ah, nominal voltage, product type or series, and the production date including year, month, and sometimes the specific production line.

Manufacturer	EVE Power
Model	306Ah
Chemistry	LFP
Form factor	prismatic
Nominal capacity	306 Ah
Nominal voltage	3.20 V
Dimensions	71.7 × 173.7 × 207.2 mm
Weight	5600 g
Energy density	175 Wh/kg
Cycle life	10000 cycles

EVE Power 306Ah