I know that. The point is, if I want to sell a kit (for the Brompton) with a custom battery, I have to get the battery tested for all the regulations listed above. It is a sizeable investment. You are looking at at least £10k in fees, £15k to be realistic, on top of tooling costs. I approached a few battery factories, they all run a mile as soon as I ask for a custom case. A commitment to 1,000 sets would still not cut it. Would the kit sell in sufficient quantity to recoup the investment? I doubt it. Even if it does, how long would it take to sell 1000 kits for one particular bike?Unfortunately UN38.8 isn't an EU norm, it is a UN norm. Most EU norms are based on ISO or other international norms. Sorry to disappoint you...
assembling e-bikes in the UK presents a similar problem with EU regulations because the certificates that were obtained for the imported bikes won't be valid for the bikes assembled here.