kzeise.com

The EU is currently considering a new battery directive¹, and as it stands, it will effectively ban AirPods, and probably even smartwatches.

The problem is article 11, which basically forces everything using batteries weighting less than 5 kg to use user replaceable batteries, with only one exception when “specifically designed to operate primarily in an environment that is regularly subject to splashing water, water streams or water immersion, and that are intended to be washable or rinseable”. That makes it applicable for earbuds, smart watches, phones, and tablets. All of these will become seriously worse products because of this misguided law.

To understand why, a user replaceable battery needs to be more robust. It will have a plastic housing instead of directly fitting the battery pack, the housing will have significantly less flexibility to fit a battery tightly, and you need to properly secure the pack. User replaceable also means that you no longer can use glue to seal your device water tight. Instead you will use some kind of rubber seal, as they were used in tough compact cameras, like the Olympus TG-6. From experience, you need to be careful. The surfaces for the seal must be clean for the seal to be any good, especially there must never be any sand on them. Then you need to fasten the seals and batteries. You can either use a cap as in cameras, which use up a lot of space, or you use screws, which are a potential ingress point for water, and you also run the risk that users will fasten them wrongly. You really want a torque sensor to tighten them properly. In short, a user replaceable battery increases weight, and volume, and makes environmental sealing heavier. And for batteries that last at least as long as the product, they add avoidable waste.

Looking at the Fairphone and the iPhone 14, you see the impact a replaceable battery can have: 225g instead of 172g, IP54 rated instead of IP68. Apart from a few idealist, people just prefer the much better phone, and with Apple offering battery replacement for €119, this is a tradeoff many are willing to make.

For smartwatches, this is a disaster. I want my watch on during a swim, so it needs really good protection, and I want it to be smallish². Design goals that currently cannot be achieved with replaceable batteries. But a watch is primarily used outside the water, even if swimming is critical use case, so the exception in the law does not take.

And for AirPods, they are worn inside our ears, so from an ergonomic perspective they need to be as light as possible. One AirPod Pro is just 5.3g, so even adding 1g to support a replaceable battery is bad. Apple uses a 25mAh battery, which I estimate to weight around 500mg, comparing them with a 210mAh, 3.2g CR2032. And the environment calls for good sealing, as you do not want your sweat to destroy them.

These are real design tradeoffs, and the law needs to recognize this. This means that it should be possible to have a battery replacement service as an alternative, when other design goals would be compromised. Difficult to put this into legal requirements, but let us try.

Amendment to Article 11:

1. Devices are conditionally exempt from the user changeable requirement when one or more important design goals recognized in this article would be negatively impacted

2. Exempt devices need to conform to all of the points below

   1. be designed that their batteries allow at least 1500 charge cycles, or that they last for at least 3 years for at least 95% of users before needing replacement.

   2. provide a battery replacement service that costs at most 50€ in 2023 euros more than a typical battery of roughly the same capacity, volume and endurance.

   3. once the battery replacement service is stopped, the necessary documentation must be provided free of charge for third parties to provide this service instead. Any necessary patents and other rights need to be licensed on a FRAND basis. This obligation includes tools, processes and replacement parts.

   4. use at least 20% of their volume or weight for batteries, or weight less than 100g.

3. Important design goals are for

   1. Asset trackers:
      1. Robustness against manipulation

      2. Environmental sealing

      3. Weight

   2. Devices that are designed to be worn on the body, taken with you all day, or to be used handheld for at least 15 minutes continuously:

      1. Weight

      2. Size

      3. Environmental sealing

      4. Robustness against rough handling

   3. Devices intended to be portable, and be used at multiple locations. These can be exempt if the smallest dimension of their rectangular bounding box is less than 20mm.

      1. Weight

      2. Size

   4. Devices intended to be used regularly in a harsh environment. These devices do not need to meet the volume/weight threshold from 2.4.

      1. Environmental sealing

      2. Robustness against rough handling

4. This conditional exemption is valid until two years after a comparable device with a user replaceable battery is available on the market that provides for those design goals at least as well, and with a volume and weight penalty of at most 5% of the entire device, with comparable life time hardware costs.