One of the most important considerations and limitations the Evangelion face is their apparent need for power in order to stay active. While this limitation is not entirely accurate as Evangelion periodically transcend their need for power when they go Berserk, often times power limitations are a defining aspect of the conflict and this is handled in a varity of ways throughout the franchise.
- 1 Umbilical Cable
- 2 Internal Batteries
- 3 External Batteries
- 4 S² Engine
- 5 Nuclear Reactor
- 6 Other Power Sources
Arguably the most important power source, the umbilical cable is the main source of power for most Evangelion units. Connecting to the upper back of the Evangelion, they provide a direct supply of power allowing them to operate indefinitely.
The connectors are visually similar to a three-point plug and have two built in retro-rockets to slow its descent and prevent damage when it is disconnected. Tokyo-3 has a multitude of power stations which house connectors and cables allowing Evangelion to quickly switch to a new cable if their current one has reached its maximum length or has been damaged or severed.
Umbilical cables are also used outside the borders of Tokyo-3 either by setting up temporary cable stations or by using extended cables.
First seen and prominently shown during the first battle in Tokyo-3 against the angel Sachiel, the umbilical cable was established to be an essential tool for the Evangelion. Through the series, most fight begins with the Evangelion connected to power cables, including in the fights which take place outside of Tokyo-3.
A portable version of the umbilical cable is seen in use in Episode 08, being airlifted via helicopter and set on the deck of an aircraft carrier, drawing power from the ship's reactor. Umbilical cables can be connected to other power sources and used far away from Tokyo-3's power supply, as seen in Episode 09, Episode 10 and Episode 18. Power cables being severed in Episode 03 and again in Episode 25'
Although they function identically to how they do in Neon Genesis, the umbilical cables importance is greatly diminished in the rebuild series only making major appearances in the first film with minor appearances in the second film before being entirely unused in the subsequent films due to improvements in technology and the need for larger areas of operation.
Nearly very Evangelion unit has an internal battery to allow the unit to operate in cases where the Umbilical Cable has been been severed or would be impractical to use. While it is explicitly stated the batteries can provide up to 5 minutes of operation, the actual time granted by the internal batteries varies greatly from battle to battle for no apparent reason.
The batteries are constantly referenced to through the series and operational time is an ever-present issue. For various reasons, the internal battery is relied on during the fights against Shamshel, Jet Alone, Israfel, Matarael, Sahaquiel, Zeruel, Leliel, Tabris and the Mass Production Evangelion.
It must be noted that despite stating that the batteries last for 5 minutes, the show itself is not consistent in enforcing this rule. There is no proper reason why the batteries should last five minutes during the battles against Shamshel and the Mass Production Evangelions but little over one minute in the Israfel battle and no reason or justification for this is ever given.
The internal batteries function identically in the Rebuild series as in their TV counterparts however the concern related to running out of power is significantly minimized, only being brought up as a serious concern when unit-01 nearly runs out of power fighting the Fifth Angel, does run out of power fighting the Tenth Angel and when Unit-02'γ runs out of power fighting against Evangelion 13.
External batteries are periodically used in situations where umbilical cables are impractical and the operation time needs to be extended beyond what the internal batteries are capable of. These batteries come in various forms and function in different ways however they all serve the same purpose.
Battery supplies can be extended using large disposable batteries located on the Eva's shoulder pylons. These provide an unspecified extra operating time and are used in the battles against Israfel and Matarael.
One of the rarest power supplies, the S² engine originates from angels and has the ability to provide Evangelion with a potentially limitless run time. Due to the nature of these engines, they have the potential to cause a great amount of damage if not properly used. They are also not perfect sources of energy, as seen in ANIMA they produce a large amount of heat which needs to be dispersed.
The first S² engine test was with Evangelion Unit-04 at NERV second branch in Nevada. During the activation test, the engine couldn't be controlled and detonated, swallowing the unit, the base and everything in a 49 kilometer radius into the Sea of Dirac.
The final units to utilize the S² engine are the Mass Production Evangelion. Unlike the engines from unit-04 and unit-01, the mass production evangelions S² engines did not originate from angels, instead being produced by SEELE in secret along with the units themselves.
The usage of the S² engines across the rebuild series is quite vague and as such, it's difficult to know for sure which units, if any actually made use of them. Since many of the important events relating to S² engines occur including the collection of the S² organ from the Fifth Angel and failed unit-04 test, it's reasonable to assume S² engines exist in this continuity.
Through the films, there are a handful of units and weapons with seemingly indefinite operation time, particularly those made by NERV which are powered by unknown sources and can be reasonably explained by the presence of an S² Engine. Most notably, these units include Evangelion Mark.06 and Evangelion 13, however it is also likely the entire Mark Series, the Arm Units and the NHG series of warships are also powered by these engines.
In addition to all variants of Unit-01 having a built in S² engine, external S² Engines were developed to extend the use of the other Evangelions. Plugging into the same port as the umbilical cable, they are derived from the remains of the Mass Production Evangelion.
The least used method of providing power to the Evangelion, internal nuclear generation involves attaching a small nuclear power plant to the back of the unit in order to provide nearly limitless operating time. While a good solution to the power issue in concept, in practice the inherent dangers associated with attaching a nuclear generator to evangelions, manned weapons who mainly fight using hand to hand combat, clearly out weigh the benefits when other alternatives are readily available.
While not used by any Evangelion units, a proposed replacement for them, Jet Alone does. When confronted by Ritsuko Akagi about the concerns of using a nuclear reactor to power a hand to hand combat machine, the creators simply deflected, likely because she had a strong point.
While not explicitly stated, it is likely that Evangelion Unit-02 (Rebuild)/New Unit-02α is powered by a nuclear reactor for a couple reasons. At the conclusion of Paris Assault Mission when the spare parts are being recovered to repair and refit unit-02 and unit-08, the parts recovered for unit-02 are labeled as "JA-02". While the rebuild continuity never showed or hinted at the existence of Jet Alone prior to this, the resemblance to the Neon Genesis design is clear.
After being repaired, unit-02 shares another resemblance to Jet Alone as they both have what appear to be nuclear control rods which protrude from their backs.
Other Power Sources
Q.R. Signums allows for the transmission of power from Armaros to Evangelion units under its control. This process is entirely wireless, relying on the integration of a special black and red scale into the body of the units. While these scales transmit power, they also corrupts the units and their pilots as evidenced by the creation of Evangelion Unit-0.0 Mutant.
The Center Trigonus is a power source used exclusively by the Super Evangelion which acts as a window for its previous S² engine, which was slipped into the higher dimensions. Yui opened a dimensional rift to restore the connection with the S² Engine, giving the control of Unit-01 body to Shinji as she went to the other side . By acting as a doorway to higher dimensions, the Super Evangelion is able to draw extradimensional energy to power itself and its weapons . This process is aided by quantum wave mirrors built into the units restraints which allow for the gathered energy to build up to power more powerful attacks.
- Neon Genesis Evangelion: ANIMA Volume 2, chapter 6
- Neon Genesis Evangelion: ANIMA Volume 3, chapter 44
- Neon Genesis Evangelion: ANIMA Volume 1, chapter 8
- Neon Genesis Evangelion: ANIMA Volume 2, chapter 46