Words that we want to never say and you want to never hear, "sorry we can't fix it". This applies most directly to eBike batteries.
For example Giant's "unserviceable" battery is indeed unserviceable. The whole battery set is covered in an insulating goo that is then shrink wrapped against the battery set. Great design as it reduces any chance of a contact separating, however impossible to service. The time required to dig out the goo makes repairs to this battery unaffordable.
As the variety of batteries we repair increases, we expect to discover other manufacturers creating unserviceable batteries. We will be sure to warn you of any batteries which we have previously identified as unserviceable. We will always discuss such issues with you and any other options to achieve a quality outcome.