2015 Jaguar XJ - low battery start engine light

My car continuously displays the warning: “low battery start engine.” I have had the battery checked and was told the battery is fine but is a little low on its charge. When I take a long trip, the warning does not appear for a few days. What should I do to ensure that I am not left somewhere?

Do you normally just do short, low speed driving? Is this a daily driver or only used occasionally? If rarely driven, you might want to consider a battery maintainer.
Have your charging system checked,.
The battery should be load tested. If it is the original battery, it may be time for a replacement, the load test may show that,

I think that is it right there… You aren’t driving the car far and long enough to recharge the battery between drives.