A new customer came to see us after the hybrid battery in their Toyota Prius hybrid failed once while under warranty and again one month after the 12 month warranty expired on the replacement battery that Toyota has installed. Toyota hybrid batteries are known for their reliability and we just don’t see many Prius batteries that fail before their warranty has expired. Their Prius was only 4 years old, but they had exceeded the maximum limit of 150,000 miles, so they had to pay out of pocket for all future repairs.
They couldn’t afford the $4,500 price tag on a new hybrid battery from the Toyota Dealership, so they purchased a low-priced used hybrid battery from one of our competitors. When that battery failed in less than 3 months, they purchased another low-priced hybrid battery from another one of our competitors and it also failed in less than 3 months.
They were about ready to give up hope when one of our long-term hybrid customers referred them to Electron. We had their Prius towed to our shop and confirmed that the battery was indeed dead. Batteries don’t continue fail without a reason, so Instead of just replacing the dead battery like our competitors did, we ran a series of diagnostic tests with our proprietary hybrid battery technology. The data history showed that the temperature was extraordinarily, almost unrealistically, high when the used batteries failed from both of our competitors.
We immediately checked the cooling system as it’s not uncommon for them to become restricted and overheat, but the computer usually detects the overheat which sets off a warning signal. That didn’t happen in this particular case and there were no overheating codes. The entire cooling system was clean and the cooling fans were so clean that they looked brand new. After that we stressed tested the sensors and everything passed with perfect scores. With nothing left to test, we reviewed the diagnostics for inconsistencies and found it odd that the cooling fans looked brand new even though the last hybrid battery installed in their Prius had been used for almost 3 months.
The computer readings said that the fan was working and registered the fan as spinning at full speed when tested. We retested the cooling system and watched how the computer registered the fan operating correctly and spinning at full speed when in actuality, the fan blades never moved. Upon closer examination, one of the previous battery installers had disassembled the cooling fan for cleaning, but failed to put it back together again properly before reinstalling it. The fan made a noise that sounded like it was working, but the blades weren’t spinning so the fan had no way to cool the battery down. The fan looked brand new because it wasn’t working and therefore wouldn’t need lubrication which is what makes it dirty in the first place.
The battery cooling fan had to be replaced because it was damaged from improper reassembly and installation. The motor spinning had rubbed against other parts of the battery and damaged those as well. The long term and properly diagnosed solution was to properly install a new cooling fan and a new remanufactured hybrid battery with a 3 year warranty.
The new battery and fan have been going strong for the last 3 years and we remanufacture all of our hybrid batteries to outlast their warranties. The owner of the hybrid could have saved a lot of time, money and frustration if any one of the previous hybrid battery installers had focused on finding what caused the battery to fail rather than just replacing the battery itself.
