I don't drive very long distances, so for literally years my car's automatic stop start just never functioned because my car battery was never juiced enough. I let the charger work its magic over a weekend and suddenly my stop start function works again. Now I use it once a month to top up my battery.
Also had another car left in storage for a while during covid and the battery completely drained. This charger managed to recharge it just fine. Just charges fairly slow, so give it a couple of days.
I highly recommend every vehicle owner keep one of these in their garage.