NHTSA Complaint #10260512 — 2001 TOYOTA PRIUS

HV BATTERY FAILURE, PRIOR TO FAILURE OF HV BATTERY VEHICLE EXHIBITED ERROR CODES INDICATING THAT AT LEAST TWO BATTERY MODULES HAD A GREATER THAN 1.2 VOLTS BETWEEN MAX MODULE VOLTAGE AND MIN MODULE VOLTAGE (HV BATTERY CONSIST OF 38 BATTERY MODULES 7.2 VOLTS EACH). HOWEVER, VEHICLE STILL OPERATED ALTHOUGH IN A FAIL SAFE MODE (NO CRUISE CONTROL IN FAIL SAFE MODE, ETC). UPON ATTEMPTING TO START VEHICLE HEARD LOUD EXPLOSIVE POP SOUND AND VEHICLE WOULD THEN NOT START. AFTER REMOVAL AND DISASSEMBLY THE HV BATTERY PACK I DISCOVERED THA TWO BATTERY MODULES, OUT OF THE TOTAL OF 38, HAD A CIRCULAR BURN BETWEEN THEIR AJOINING PLASTIC CASES AND THE TOP OF ONE OF THE TWO MODULES HAD EXPLODED OPEN -- EXPOSING THE BATTERY PLATES INSIDE (BOTH BURNED CELLS NO LONGER MEASURED 7.2 VOLTS, BUT ABOUT 0.32 VOLTS). BURNT SMOKE RESIDUE SHOWED ON TOP OF THE HV BATTERY PACK INSIDE METAL HOUSING AS WELL AS ON THE ONE BATTERY MODULE THAT HAD AN EXPLODED TOP. I REPLACED THE HV BATTERY PACK NO FURTHER ERROR CODES HAVE BEEN NOTED SINCE REPLACEMENT. DAMAGED MODULES SHOWED EVIDENCE OF AN EXPLOSIVE FORCE OCCURRING AND BURNING OR SHORTING BETWEEN BATTERY MODULES. *TR