Hi,
Low MTTR:
"...the top three reasons for Boeing returning batteries” as batteries running down, being improperly disconnected, or exceeding their expiration date."
A battery that’s left on with no other power source, Gunter said, “will deep discharge (and) cannot be recharged or reused.”
And one that’s improperly disconnected, she added, “trips one of the protection features and renders the battery unusable.”
Because lithium-ion batteries can be dangerously volatile if undercharged, as well as when overcharged, an automatic cutoff is built into the 787 batteries so that if the charge falls below 15 percent of full, the battery locks.
After some problems during trips, some years ago i opened and analyzed the 6 cell battery pack of my main laptop. The voltage span from empty to full used in that design was just one volt. IIRC 11.6 to 12.6 Volts. I decided to use an external battery for my main and spare laptops. Currently i use 12 cells, charging each one up to 4.2 volts with constant voltage monitoring. Warning me if a given cell falls below 3.3 volts during operation. Result: 10 hour plus operation.
Ea. cell can be replaced. (18650)
