https://hybridautomotive.com/pages/install-i1.html
Allow the car to sit overnight.
Without unplugging the grey connector plugged into the left box in step 13, probe the tap voltages and record them (picture inverted to represent the orientation of the plug):
If those 10 voltages are within 0.2V, VERY good chance of getting more life with a Hybrid Automotive grid charger/discharger kit.
If they are 0.4V, it's a decent chance.
If they are more than 0.6V, it's a poor chance.
These are not HA recommendations. They are based on my own observations.