Instead of measuring whether a Voltage drops, like the aforementioned -dV/dt termination, this one does it in a different way.
When a battery is depleted the Voltage is lower than when fully charged. When you charge a battery, the Voltage will rise over time. But at a certain Voltage, the battery stops increasing its Voltage, and therefore the charger could determine to stop charging. The 0 dV refers to 0 Voltage difference at x amount of time. As the battery tester, HKJ, has pointed out, this type of termination is sometimes difficult to distinguish from a -dV/dt termination.
A charger like the Lacrosse BC700 probably uses this termination, especially at a lower current.
This is not a recommended termination for NiMH rechargeable batteries, and therefore neither for Eneloop batteries.
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+ What is -dV/dt charging? (termination)