Non-exploding batteries

Compact lithium batteries, like those in your smartphone, are integral to making future space missions more efficient.

While we know the commonplace stories of batteries catching fire on planes, we still don’t know the full extent of how batteries will behave after several years in orbit, due to radiation and uncontrolled temperature ranges or unregulated power control leading to them becoming overcharged, opening the door to possible in-orbit explosions.

Disposing of space debris is one of the greatest challenges facing ESA and the space industry at the moment. Airbus Defence and Space (France), in partnership with CEA (France) and the two main European battery manufacturers for space Saft (France) and ABSL (England) have just closed an activity with ESA's Technology Development Element programme (TDE). The activity was part of the Clean Space campaign to assess how best to make a spacecraft's battery safe or completely discharge it at the end of a mission so it can be disposed of properly. 

The activity found that the only way to make a battery completely safe in the extreme conditions of Space is to remove them or to deplete their power to below 0 Volts, making sure they can’t overcharge and cause catastrophic explosions.

They also recommended other protections to prevent overcharge, such as adding independent monitoring circuitry (relaying information about the battery's voltage or temperature to remote monitoring stations) so that if the temperature or voltage exceed a certain level then operators could remotely interrupt the battery, stop it charging and avoid any potential danger. In nominal mission, overcharge is prevented through voltage and current regulations applied to the the power subsystem, and maximum voltages are standardised across the space industry, but this alone might not be enough. 

 Contract: 4000115460/ T703-404EP closed in December 2018.