Originally Posted by
seedsbelize2
The 2017 Fit, purchased in 2018, has lost its second battery. 70,000 km. I just came from Fit Forums, and it is a common problem. Seems the battery is just too small, and the 'smart charging' is dumb. Folks are disconnecting it and getting better life. Beware @
datlas. How about you, Humbug? Battery issues?
This issue isn't just specific to Honda but even Nissan/Infiniti utilizes this so-called "smart" charging. The negative terminal has a battery current sensor and it basically sends a signal to the ECM to say when the alternator turns on to start charging the battery. That usually starts after driving a certain amount of miles but if you have short drives or if the vehicle sits for an extended time, the battery weakens to a state where its not strong enough to start the vehicle. One of the first mods I did on my QX80 was disconnecting the ECM signal wire from the battery current sensor. I didn't want that so-called "smart" charging just to supposedly gain 1mpg, if that. The alternator works traditionally as an alternator should without having to wait for the ECM to say when to turn on/off.