Thanks for your question!
You’re right—most smaller cordless rotary mowers have a minimum cutting height of around 25mm, which can be limiting if you’re looking for a really close cut. If achieving a lower mowing height is a priority, you might want to consider a cylinder mower rather than a rotary mower, as cylinder mowers are designed to cut much lower and give a finer finish, especially for lawns that are maintained like a bowling green or ornamental lawn.
Brands like Allett and Cobra both offer cordless cylinder mowers with cutting widths in the 30–34cm range and the ability to mow well below 25mm—some models can go as low as 6–10mm. These could be a great fit if you want that lower cut.
If you prefer to stick with a rotary mower, Hayter does make a cordless rotary mower (the Hawk 36, for example) that can cut down to 19mm, which is lower than most in this size category.
Hope this helps! If you need any specific model recommendations or have more details about your lawn, feel free to let me know.
Best regards,
Mark