Great thread! And sorry for the resurrection.
I am looking at some honda CRZ's (from 2011-2012) and will inevitably run to the battery problems if i purchase the car.
Is the information in this thread still valid or have the solutions proven to be only temporary and not worth the time and expense.
For constant charging would something like this be any good?
Boost converter with 12v input and adjustable voltage output (200mA max)
High Voltage DC DC Boost Converter 8 32V 12V to +/ 45V 390V ZVS Capacitor Charging-in Inverters & Converters from Home Improvement on Aliexpress.com | Alibaba Group
Also if you install the leads, could you not stick more batteries in the trunk and have 160V with a diode and 10A max. Would this improve FE?