Battery Pack Error caused electrical fault ?

[yehreally]

Any help with the following would be appreciated... Car battery ran flat so connected a battery pack to boost the charge and get the car started. Unfortunately connected the pack the wrong way round.......................

Car is now having a few electrical problems (ecu fused but now repaired) and would like to know what else is likely to have happened and what from your experience is going to need replacing/fixing ?

Thankyou for your help in advance.