Dismantling and Maintenance of a Toyota Hybrid Battery

Let’s see how to maintain a traction battery of a Toyota Hybrid. Dismantle the battery pack, remove and clean all contacts, and take apart each cell, cleaning all the channels where the fan circulates air to cool the cells.

This helps preserve the cells. First, disconnect the traction battery fuse by sliding the orange handle of the fuse, then pull it towards you and remove it. To replace it, follow the same procedure in reverse.

Ensure the sliding mechanism is engaged to arm the fuse. Once the battery cover is removed, you will see it consists of several cells, each with a voltage of 7.2 volts and weighing about 1 kg. The battery appears clean, but dirt accumulates between the connections in the cells where air circulates.

Some contacts may be oxidised; clean each one individually. If they are dirty, when the external temperature is very high and the air passing through cannot cool the cells, the control unit will not operate the traction battery to prevent overheating.

Proper maintenance of the battery cells extends their lifespan. Dirty and oxidised contacts can trigger the dreaded "hybrid system error," which is a nightmare for all hybrid car owners.

This is because the contacts send incorrect signals to the control unit. If the fan is dirty, the blades can jam, preventing sufficient air from reaching the cells, which can overheat.

The voltages of each individual cell are checked and found to be uniform, including the central ones, which are generally the most problematic, so they are in excellent condition. All have been cleaned with compressed air. Additionally, the cleanliness of the vehicle's interior affects the traction battery, as the fan attracts dirt from the mats and the interior of the car; therefore, if the interior is clean, the battery remains so as well.

The dark plastic supports at the bottom of the battery are essential for proper airflow circulation pushed by the fan within the battery itself. If they are missing, the vehicle may go into lockdown during summer.