Hi @christiangudito
A blinking amber battery charging indicator means that the AC adapter is connected but the rechargeable battery cannot be charged as the battery is too hot or too cold for charging. The charging process is continued as soon as the rechargeable battery has reached a permissible temperature again.
Assuming that the ambient temperature around the laptop is OK perhaps the battery is failing (faulty?) and needs to be replaced.
Here's a [https://www.manualslib.com/manual/2253335/Fujitsu-Lifebook-E546.html?page=35&term=battery&selected=2#manual|link] that shows how to remove the battery pack from the laptop.
Search online for ''Fujitsu Lifebook E546 battery'' to find suppliers that suit you best.