Each manufacturer has methodology and equipment to test their hybrid batteries. The results of these tests will determine the serviceability of the batteries. In some cases, individual cells have been replaced to correct a faulty battery, but this is not common professional practice, so the individual cells are not likely to be tested.

Replacing the hybrid drive high voltage battery will be done by disconnecting the 12-volt and high voltage battery in the manufacturer specified manner and order. Once disconnected, protective covers may be used for the battery terminals. The battery access panels, if not already removed, will be removed to access the battery before lifting it out of the vehicle. Since the battery for a hybrid drive system is both bulk and heavy, it is important that the battery be lifted properly, and, in some cases, a hoist be used. Reinstallation requires the reverse of operations, but some software updates and operations may be required.

We do not recommend attempting to service the hybrid high voltage battery. There are may videos of people who have chosen to service these batteries in hopes of saving money, and there are also many failures, injuries, and destroyed electronic components from the same.

The term 'high voltage' is placed around every connector for the hybrid drive system, and the high voltage power wires for the hybrid high voltage battery are typically coated in a very obvious color like red or yellow. This is to prevent the connections, wires, and, generally, any part of the system from being contacted by the consumer. Read the owner's manual before attempting to open the hood or battery compartment. It may prevent serious harm or death.

This repair is not recommended for the DIY mechanic unless the proper high voltage hybrid drive battery service training has been completed. Not only is this a dangerous operation if done improperly, but it can damage many components in the vehicle if service improperly as well.