I recently noticed while having my camera battery charger plugged into a 75W inverter that was plugged into the lighter socket under the dash, the car display for the current MPG often read 99.9 mpg when it was not suppose to. It didn't seem to have any affect on the average mpg. The 2W charger seemed to be working. Why would the current mpg show 99.9 so much from this? Are there any other concerns I should be aware of having this little inverter plugged in to the lighter socket?
No way to know for sure without instrumentation, but it sounds like the inverter could be putting out a large amount of noise pulses, that are interfering with the BEAN network signals and causing errors in the data on that bus. The car networks are supposed to be fairly noise immune, but I know from experience that some cheap inverters can also be very poor at suppression of their own hash. You could try putting some noise suppressing ferrite clamp-ons on the 12V lead of the inverter and see if that helps.
Thanks for the reply. Good catch. Yes, it is a cheap inverter from China. Are there any concerns I should be aware of using this inverter?
Nothing much to be concerned about, just don't overload it. Probably just an internal soldered in fuse for protection. I think there are ferrite suppressors available at Radio Shack.
