The IMA battery (Integrated Motor Assist) in my 2006 Honda Civic Hybrid started acting up a few months back – suddenly having a very low charge and then, a few minutes, saying it was fully charged. Finally, the Check Engine and IMA fault lights showed up – and the verdict was in. I needed to have the IMA battery replaced.
Fortunately for me, in California the IMA battery is warranted for 10 years or 150,000 miles – so Honda replaced it at no cost to me.
The difference in performance of the car – no surprise – is significant. That electric motor boost from standing stops is back and things feel almost like new!