[gbgb]

In theory a gel cell can be mounted in any position except upside down. But, frankly I think you should keep resisting unless you are really really stuck.

Two reasons:

The structure of the battery is stronger when on its bottom. On it’s side and especially on its end it is POSSIBLE for the plates to separate from the gel mat. This may be worse with the bumping and banging it will get in handling and landing.

The gel mat shrinks a little during the life of the battery. placing it on its side MAY cause gaps between the plates and the mats.

Both of these reasons can affect the capacity and life of the battery. I don’t think anyone has tested this empirically, but you don’t need to test it at your expense