Hybrid High voltage battery will not charge above halfway?

I would start with a CAN scan to see if the Hybrid battery controller is having a problem. You can get a CAN scanner (Controller Area Network) which will work on most cars from Amazon.

Here is a video to show you how:

https://youtu.be/u-4syLc-ifQ

and

https://www.2carpros.com/articles/can-scan-controller-area-network-easy

Here is one for about $99.00 if you need it:

https://amzn.to/3ZixY4v

There are a few things that could cause your 2013 Lincoln MKZ Hybrid's high-voltage battery to not charge above halfway. Here are a few possible causes and solutions:

Faulty hybrid battery pack. If the hybrid battery pack is faulty, it may not be able to hold a charge. This can be caused by a number of things, including old age, excessive heat, or physical damage. If the hybrid battery pack is faulty, it will need to be replaced.

Faulty hybrid battery control module. The hybrid battery control module is responsible for managing the charging and discharging of the hybrid battery pack. If the hybrid battery control module is faulty, it may not be able to charge the battery pack properly. If the hybrid battery control module is faulty, it will need to be replaced.

Faulty wiring or connectors. The high-voltage battery is connected to the vehicle's electrical system by a series of wires and connectors. If any of these wires or connectors are damaged, it can prevent the battery from charging properly. If there is a problem with the wiring or connectors, it will need to be repaired or replaced.

Low coolant level. The hybrid battery pack is cooled by a special coolant. If the coolant level is low, it can cause the battery to overheat and prevent it from charging properly. If the coolant level is low, it will need to be topped up.

Defective cooling fans. The hybrid battery pack is cooled by a series of fans. If the fans are defective, they may not be able to cool the battery properly. If the fans are defective, they will need to be replaced.

If you are experiencing this problem, it is important to have your vehicle diagnosed by a qualified mechanic. They will be able to identify the cause of the problem and recommend the best course of action.

Here are some tips to help prevent this problem from happening in the future:

Get regular maintenance. It is important to get regular maintenance on your Lincoln MKZ Hybrid, including oil changes, tire rotations, and brake service. This will help to keep the vehicle's systems in good working order and prevent problems from occurring.

Avoid extreme temperatures. The hybrid battery pack is sensitive to extreme temperatures. Avoid parking your vehicle in direct sunlight or in very cold weather. If you must park your vehicle in extreme temperatures, try to park it in a shaded area and keep the battery charged.

Avoid overloading the battery. Do not overload the hybrid battery pack by driving at high speeds or using the air conditioning for extended periods of time. If you must do these things, try to do them in short bursts.

Please let us know what you find. We are interested to see what it is.