Why do we use battery holders when testing cells?

Holders? Fixtures? Contacting Systems? Jigs? Whatever you call them they ensure reliable, accurate results and are essential for lab efficiency when performing cell testing.

Battery cell testing is essential for evaluating the performance, safety, and reliability of battery cells used in various industries such as the EV market. Proper electrical contact is important for achieving accurate test results, and holders ensure this consistency. Below, we outline why holders are crucial in a battery test lab and how Cognition Energy can provide industry-leading solutions.

Why do we need battery holders for cell testing?

Accurate, high quality data

High quality electrical connections are essential when cell testing, ensuring the data being used for analysis is accurate and fit for purpose. Poor electrical connections can introduce resistance variations and overheating, leading to inaccurate voltage, current, and impedance readings. Holders ensure minimal contact resistance (typical <1mΩ), leading to reliable and repeatable results.

Improved data analysis

Consistency in testing is key for accurate performance assessments. Standardised holders eliminate variability introduced by different test setups, ensuring each battery is tested under identical conditions. This leads to improved comparative analysis and compliance with industry regulations.

Easy to use and efficient

Handling battery cells manually can be inefficient and prone to errors, causing costly delays and potential errors within the data. Holders streamline the testing process by securely holding the cells in place, enabling quick, easy and repeatable loading and unloading of cells. This reduces the lab’s down time, increasing overall efficiency.

Safety

A well designed battery holder enhances safety by reducing the risk of accidental short circuits, overheating, or mishandling of the cells.

What other things can you do with battery holders?

Not only are battery holders an essential piece of equipment when cell testing for performance, characteristics and storage, they can also assist by creating conditions that mimic the real-world situation the cell may be used in.

Compression

For both pouch and prismatic cells, it is common for these cells to be under pressure when used, which improves performance and lifespan. Therefore when testing, it is ideal if the same pressure can be applied to mimic these conditions. Compression holders with integrated pressure monitoring enable this.

Pouch cell expansion

If compression of the pouch cell is not done, swelling is likely (or will occur). It is useful to measure the level of expansion during testing, to understand how this may affect the real world scenario. There are multiple options available to measure this as part of the battery holder.

Thermal management

In real world conditions such as in EV’s the cooling system for the cell is done via liquid cooling rather than air cooling. Thus testing in a traditional thermal chamber which is heated & cooled via air, does not mimic the conditions the cells will be used in. In order to get results most similar to this scenario a thermal battery holder should be used, for example the CellPod One.

How can Cognition Energy help your next battery cell testing project?

Cognition Energy are experts in designing and fabricating battery cell testing holders. With our in-house R&D team and workshop we have the expertise to design and create holders to customer specification, with rapid turnaround times. Our holders are high quality and proven, used by ourselves in our test services.

From coin to blade cells, we can create holders for all cell types. Examples of the cell holders we produce include:

Individual battery holders

We produce all standard sized battery holders from coin cells to blade cells, with customised sizes as required. All holders are designed and created by our in-house engineering team, guaranteeing that our holders are reliable.

We also produce some adjustable holders such as the CF-46, suitable for 4680-46120 cylindrical cells. These holders also have more flexibility and saving time whilst cell testing.

Further to the above more complex holders are available enabling the cell testing conditions to reflect the end user environment, these include:

Compression holders for pouch and prismatic cells with integrated pressure monitoring. Both fixed gap and fixed pressure are available.

Expansion measurement systems for pouch cells via:

Archimedes principle volume change measurement
Laser thickness change measurement

Battery Holder systems

If flexibility and time management are key requirements, our battery holder systems are essential. These custom-built racks fit seamlessly into your thermal chamber and are equipped with quick-release battery holders, which easily swap with just a push and a click. This approach eliminates the need for users to handle cables within the thermal chamber, boosting efficiency, reducing the risk of errors, and enhancing staff safety.

Are you interested in some new battery holders for your next project? Contact us now to discuss your requirements.