All Triumph Models
When supplied from the factory, all models were fitted with a small rubber friction pad that provided restraint to the battery, in conjunction with the restraining bar and bolts, so as to prevent movement under hard cornering of the vehicle. It is obvious that a hard plastic battery case will slide easily on the metal of the battery box. Hence the need for a friction pad to act as an anti-slip medium.
It is strongly recommended that to avoid battery movement and stressing the battery leads, not to mention the potential for a dead short should the live battery terminal contact a metal ground source, a friction material be placed between the battery case and the battery box. Note, this applies equally to a plastic or fibreglass battery box insert as it does to a a metal battery box. A friction pad can be readily made from section of protective foam plastic wrap, not bubble wrap, or a few strips of self adhesive weather-stripping such as used for sealing exterior doors on houses. Whatever is used, make sure that it will not dissolve in solvents or oils that are common the engine bays.