NY Times: Thirsty Batteries Tell Rechargers How Fast to Pour

ith some battery rechargers, restoring a couple of double-A’s can take up to eight hours. But with Rayovac’s new I-C3 system, batteries can be charged during a coffee break.
Charging a battery too fast builds up internal pressure, so Rayovac gives each nickel metal-hydride I-C3 cell a switch that senses pressure and interrupts the charging current when necessary.
(full story)