Most of the newer car battery chargers won’t work unless they detect some voltage from a battery.
This means that they won’t work to charge a completely dead car battery.
Not the case. A charger will pulse at zero volts in order to sense the current. A totally depleted battery looks like a dead short. For an open circuit, that pulse will draw no current. That makes the charger assume there is no battery connected.
Yes, I have two car chargers that behave exactly that way.
Some chargers of rechargeable AAA-D NiMh batts, and of 18650’s (etc.) also need a decent bit of voltage on the battery for the charger to work.
So, sometimes I have to give a low battery a bit of a charge from a dumb charger or from another battery with a 10 ohm resistor in series, THEN put the run down battery in the smart charger. Often but not always, the “too depleted” battery can be recovered.
(I try to avoid running rechargeables “way down”, because it is quite hard on them, but, that’s sometimes hard to avoid...)