Yes 9.7 is low. Possible a bad cell in battery.. Charge with external charger and see if that helps.. Charge to 14 volts if you can
Or .. Well I have a big, and I mean BIG Deltran Battery Tender
3 modes
1-2 amps (Battery tender mode) auto switch between absorption and float
20 amp BOOST this takes it to 14.1 volts then shuts down. Has to be manually initated
70 amp Jump start.
Wi-Fi connect to Android (I think IOS and computers)
Worked for me when my converter failed last week. (took 24 hours to hit 14.1 but it did the trick) that was Sunday. Tuesday I got a new converter.
