While NiCad batteries have their own issues, they have been proven to be very stable.

FORBES: Lithium Batteries Not Ready for Prime Time in 787

To be technical they have moved from nickel cadmium (NiCad), through nickel-metal hydride (NiMH) to lithium-ion (Li-ion).

FORBES: Running in place

While memory effect was an issue on NiCad batteries, Lithium Ion units don't suffer from the same issue.

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