My mechanic run a 2 hour test on this 2006 Prius and came the with conclusion it has an issue with bank one, however voltage is 7.8 and above on all 28 cells, when first starting the car the pack shows 238 volts then after a few minutes it drops to 214 volts, hence then goes into limp mode, any help at this point would be great, I thank you in advance
If your HV battery is 238 V (80% SoC) and then drops to 214 V (40% SoC) in a matter of minutes, I'd say your HV battery has seen better days. You also don't say what load is on the battery in those few minutes, any idea? Your best plan of attack may be to work out the best way (for you) to replace all modules with brand new ones.
Voltage is one piece of a larger puzzle for battery module health. Capacity is the real key with internal resistance being secondary. Voltage follows.
