Back in August 2010 we received a 1999 Prius Nhw10 from a workshop for battery reconditioning. We informed them that on top of their normal service they had to change the MAF sensor and check the plug in coils. We did the reconditioning and returned the vehicle.
Unfortunately we got this vehicle back 3 times between August and December for repairs on the battery under warranty. Each time we repaired the battery we would clear all error codes. We receive the vehicle again in January 2010. We again fixed the battery. The vehicle would drive well but after about 1 KM the tortoise would appear and the battery capacity drops to yellow. It would take some time to charge up to green and then would work well for a while. Then again the tortoise will be back and the process repeats. This time we decided to check the engine section.
First was the spark plugs as the condition of the spark plugs can tell you alot about how the the engine is performing. First turn and to our surprise the spark plugs were quite loose. We removed no4 and there was oil at the top of the washer which was outside of the combustion chamber. This meant that there was compression leakage up through the spark plug. The other 3 plugs were also loose but no oil was seen on the outside of the plug.
After replacing the spark plugs with the correct torque the vehicle ran much smoother. It also showed up a low capacity cell which we replaced. The lesson here is that hybrid battery reconditioning is a thankless job. It is quite often that the battery that we repaired and reconditioned is damaged by a poorly performing engine. Unfortunately for us the customer always look to us as the battery is always damaged.
It has come to the point that we are put in the position of diagnosing the problem with the vehicle which has nothing to do with the hybrid battery but is the cause of the battery failure. In this case we never look into the engine section because this was already done by the workshop concerned. the result is that we were blamed and chastise for not being able to repair the battery correctly. As I said it is a thankless job.
