787 Batteries and Chargers - Part 1

[RR_NDB]

Testability issue

To be reviewed

Hi,

787 innovative design introduced Li Ion as main battery for the first time in (av) industry. We may think the battery will sit and wait most of their lifetime "waiting" for an emergency" in the DC bus. A very rare (very low probability) event.

If it happens how we can guarantee it will be able to supply the required power to the bus. (If it is not being used). Redundant elements (kept "offline") poses a Testability problem to the designers.

I donīt know how Boeing dealt with this issue. You may apply short duration pulses (discharge) to the cells to check itīs voltage "under "heavy" load.


The harness showed in battery pictures could be connections to the many cells and constituents of a BITE. We will be able to later verify that. The Built In Test Equipment could also be used to limit the cell voltages considering the series charging requires it due cells mismatch in the stack.

To be reviewed