I bought a used Accu-Cycle at a very good price and it works well with a minor flaw; the readings are off by 15%, in minutes and mAh. It’s a bit bothersome having to calculate the actual reading every time.

It would likely cost just as much or more than I paid for the unit to send it Hobbico and pay them (beyond warranty period) to re-calibrate the unit. Is it possible to adjust this myself and how?