If not using a vehicle use a battery tender that start charging at 12.6 V and stops at 14.2 – 14.5 V. Not hapy with comercial battery tenders, I made my own using a NE555 timer as precission comparator an more component. I can adjust ON at 12.6 – 12.7V and of at 14.2 to 14.5 ...
The spikes might be due to the blinking security icon on the dash. #26 Mendel Leisk, Aug 2, 2023 Last edited: Aug 2, 2023 pasadena_commut Senior Member Joined: May 2, 2019 1,797 535 0 Location: Southern California Vehicle: 2007 Prius Model: N/A Battery trouble. said...