Unstable power cell

An unstable power cell is a power generation unit of mechanoid origin. It has a constant output of 400W and can be uninstalled and moved anywhere, but if damaged or destroyed will explode. The cell bears some similarities to the vanometric power cell in that it will create free energy infinitely and cannot be built by the player.

Acquisition[edit]

Unstable power cells can be claimed and looted from mechanoid clusters after the cluster is defeated.

Beware of mechanoid turret explosions damaging unstable power cells, resulting in a chain explosion that can easily kill nearby colonists. Their presence presents a strategic choice; detonate the power cells from a distance to make the cluster easier to defeat, or carefully deal with the mechanoids to claim the cells for use in your base.

Summary[edit]

Unstable power cells output a continuous 400W of power without fuel, weather, or any other dependence. Only an event or condition that stops all electric devices, like a solar flare, can interrupt this item. They glow with a radius of 4.

Unstable power cells will explode upon losing 50% of their hit points, sparking and emitting a hissing sound for 240 ticks (4 secs) first before exploding. They also explode immediately upon destruction, regardless of method, but not upon deconstruction. An exploding cell deals 50 Bomb damage in a 9.9 tile radius. Bomb damage is multiplied ×4 against impassable structures (such as walls) and plants and ×2 against passable buildings (such as dining chairs). All nearby raiders will attempt to move out of the blast radius before detonation. ^[All?]

Like all mech cluster buildings, they have a Flammability of 0% and also take no damage from attacks with the Flame damage type. This is in contrast to, for example, a stone wall which will not be ignited by molotov cocktails but will take the 10 flame damage from the initial attack.

Explosive Radius
Light Radius. Yellow: 50%, Orange 34%.

Analysis[edit]

Example of the honeycomb rendering unstable power cells essentially safe. Note: Sandstone walls or stronger are recommended.

With its large blast radius and high damage against structures, an exploding unstable power cell is very effective against the mech clusters in which they generate. Successfully retrieving a power cell can sometimes be difficult, and should be weighed against using it as an explosive, but retrieval is usually worth it.

While cells only give a modest 400 W, they are quite useful for power. They are mobile, maintenance free, and consistent. For example, a single cell can power 2 isolated deep drills, without the need to run a long power conduit line. They are also helpful as "free" power, as a supplement to your main grid. Over the life of a colony, many cells can be accrued, contributing a significant amount of power. Deconstructing one is almost never worth it, due to the pitiful yield.

Some players are wary of their explosive nature, but the risk can be almost entirely mitigated by enclosing the cell with walls as shown in the image to the left:

A single explosion cannot damage tiles beyond walls, even if the wall is destroyed. This means all other items, structures, or pawns are safe if the cell is surrounded by walls at the time of detonation, regardless of their HP at the time of detonation.
The explosion from the cell or a high-explosive shell will deal 100 damage to other cells and 200 damage to walls.
Therefore, if you use walls made of sandstone or stronger, they will tank any damage from an initial explosion, such as a mortar strike, and the resulting cell explosion and nothing beyond the wall will be harmed.
As mechanoid buildings, they are completely immune to fires and to any short circuit that doesn't have 4,900 Wd stored, equivalent to 8.16 completely filled batteries.
Most raiders will not try to break walls if any other target is available. For sappers and breachers, place the walled cells in an internal position, so they have to break your outside walls first.

Thus, when used for static power production, they can be kept safe by surrounding them in stone walls even if such cells are placed directly next to each other in a checkerboard pattern - see the image to the left. This makes even a direct mortar strike, already a rare occurrence, result only in the loss of the cells themselves and, even then, only if they are not placed under overhead mountain.

Acquisition strategies[edit]

The primary risks to cells are accidentally triggering them with stray gunfire during combat and the explosions from destroying turrets. Several methods can be used to safely acquire power cells from mechanoid clusters:

The simplest strategy might be simply clearing the cluster. If the unstable power cells are far enough away from turrets, you may be able to recover the cell by luring mechanoids away from the cluster, and then avoiding explosive weapons and not causing more damage than needed while you destroy buildings.
Smoke launchers can be used to give colonists cover while you construct a wall around a power cell to protect it.
The Wallraise psycast can be used to surround turrets or cells to contain explosions or protect cells from stray bullets.
High-quality breach axes and pawns with improved melee damage can destroy turrets in one hit, preventing the low-health explosion. Keep in mind that this is not perfectly reliable when dealing with predamaged turrets as they may hit the target with the weaker handle attacks instead of the devastatingly effective head attack, and this may drop them below the threshold for low-health explosions. Always check the turret's HP before and while attempting this strategy, including if the first several swings do not successfully destroy a previously full health turret.
Frag grenades destroy turrets in one hit, preventing the low-health explosion. Frag grenades have a forced miss radius of 1.9 tiles, which means directly targeting a turret may lead to a grenade landing anywhere in a radius around the target, potentially hitting nearby unstable power cells. If this is possible, aim the frag grenade throws slightly away from both the turret and the cell so that you destroy the turret with a grenade that flies off-target. Destroying turrets this way takes many attempted throws. Smoke launchers can again be used to give your colonists cover from the turrets while you work.