Failing 12V or Converter issue?

[alohart]

Speaking with a friend who has had an i3, he thinks that one or more of the battery cells/modules may be bad.

I've called up BMW and they want ~$1k to update the software and run an HV diagnostic. My 1 week old i3 is already becoming a money pit.

Does anybody on Oahu have an independent shop that they would use for diagnostic and/or module replacement that they could recommend?
(pics all taken 24hrs apart from each other, 48hrs in total)

One or more very weak cells could be the cause, I suppose. However, your i3's battery pack warranty has expired, so even if BMW of Honolulu returned a diagnosis of a bad module (individual battery cells cannot be replaced, only 12-cell modules), you would have to pay for a repair which would almost certainly be a complete battery pack. Replacing a bad module wouldn't be a good repair because its cells would have different capacities from cells in the other 7 modules resulting in a poorly performing battery pack. The cost of a new battery pack would far exceed the value of your i3.

I have a smartphone app that could display the minimum and maximum cell voltages, temperatures, charge levels, and capacities which should detect whether at least 1 cell is weak. I live in Hawaii Kai. Send me private message ("Start conversation") if you would like to have this app display info about your battery pack.

However, the best solution would be to return your i3 to the seller for a full refund.

 

[EdG]

Thank you Alohart, PM sent!

Quick update to add today's report, 0.5% down, though range up. A drastic change from the 25% lost the other day, and 4.5% the day prior.

Will keep on it daily if possible to document the decreases