I have been told not to charge a frozen Li-ion battery. You can try using them in cold weather; they are very popular for ice augers for ice fishing, but charging a ‘frozen’ battery is supposed to damage it.
The “rapid chargers“ use sensors to monitor battery heat, reducing the likelihood of damage, aside from the convenience of charging the battery faster.
Philbert
The “rapid chargers“ use sensors to monitor battery heat, reducing the likelihood of damage, aside from the convenience of charging the battery faster.
Philbert