My guess is you were on the TTG screen or minutes until empty at the current load.. "I" is the current screen.. TTG means Time To Go, in minutes, at the current amp draw...The only thing I changed was the size of the bank. The default is 200 and I changed it to 400. I did a manual setting for SOC and it quickly went to zero because of the large draw. Everything was turned off so there should have only been a draw of .2 amps. I always had this on the old Blue Seas amp meter. After this didn't work I reset to the factory settings and is still showed - 850 fluctuating. The screen is one of the ones that you scroll through that shows the voltage. I can't give the letter on the left side as I don't remember and the manual is on the boat. The voltage shows as correct and was 13.06 after charging.