Battery holders: what you need to know
Battery holders: what you need to know
The primary function of a battery holder is to keep cells securely fixed in place while providing power for an application. Developers may incorporate them within the body of an electrical item, but they’re also frequently used as external compartments or attachments.
They can be highly beneficial to some devices, particular in consumer applications (e.g., remote controls) where batteries can be replaced with ease.
But there are drawbacks to relying on battery holders.
Here we explore the pros and cons of battery holders and explain what you need to know before designing your application.
A solution with drawbacks
Battery holders can remove the need to distribute thousands of devices with batteries included. It allows the end user to exchange batteries and use their own supply to power the device – removing the burden from the device manufacturer.
This allows for flexibility, particularly for popular battery sizes and shapes, including both AA and AAA versions.
However, despite this, Saft tend to not recommend battery holders for industrial applications due to the risks involved.
Poor cell quality
First and foremost, giving users the chance to switch to sub-standard batteries poses a risk to the device – in terms of performance and lifespan.
Sub-standard quality batteries might not meet the requirements of the device itself. We pride ourselves on our accurate datasheets that align with the performance of our batteries, but that might not always be the case for off-the-shelf alternatives. It runs the risk of users substituting in batteries that:
- Cannot deliver the required power across the device’s range of operating temperatures.
- Do not have the capacity to deliver the required power over their lifetime.
- Do not have the capacity to deliver the required energy during their lifetime.
These issues of sub-par performance can all increase the risk of critical failure. That’d be bad news for a remote control, but potentially devastating for an industrial application. They can also make the device unsuitable for use over the intended lifespan and that will mean more regular replacements and, ultimately, a higher total cost-of-ownership.
There is a risk of user error, in which batteries are placed improperly into the battery holder and positive and negative polarity of the battery is reversed.
This may draw enough current to damage the battery itself, but the bigger concern would be a short circuit of the device that causes irreparable damage.
There are batteries that have battery reversal protection (whereby protection on the negative end of the battery prevents an electrical contact between the negative ends of a reversed battery and the battery next to it in the holder) – but there is no guarantee that the device’s user would select batteries with such a feature
Corrosion occurs when volatile chemicals or gases inside a battery escape and come into contact with the highly-conductive metal of the battery holder. Lithium-ion batteries are less likely to leak electrolyte or any other chemical materials in normal conditions – but the risk of this is heightened with poorer quality batteries.
Another common cause of corrosion is exposure of battery terminals to bad weather conditions. Where battery holders are external or separate to the device itself, it can make it more difficult to protect batteries against the elements (wind, rain, heat) and so corrosion is more likely
When corrosion in a battery holder occurs, it can impede the flow of power from the battery to the device using it. This less-efficient power transfer means a decreased power output from the batteries and poor performance and, in extreme cases of corrosion, total device failure.
While the above risks exist for poor quality substitutions in single cell applications (using one battery), they are amplified in battery holders with multiple cells.
For a better connection between the cell and the device, and for optimum performance over the device’s intended lifespan, we recommend steering clear of battery holders in most circumstances.