Some information clarifying the specs on Sera's beloved pet tank. All of this is can be taken as in character knowledge for anyone that knows she's keeping a tank.
-Sera houses the Tachikoma in several places. One is on the roof of the apartment, another is in the back lot when she's positive no one is looking or cares that it's there, and the last is in the basement. ((Which the Tachikoma *barely* fits into.)) She puts it in a shelter whenever the Tachikoma is outside and it looks like the weather will be harsh. The shelter consists of a tarp with strong clothes lines and weights, enough to keep rain and snow off the Tachikoma.
-For maintenance, the Tachikoma is typically taken out of the Marvel world and to places like the Ghost in the Shell universe, or possibly the Nexus. Sera always tags along and makes a day trip out of it, enough that she's picked up how to fuel the tank. That would be the limit of what she can do for it, though.
-In terms of ammunition and equipment, the Tachikoma has standard equipment; one arm mounted machine gun, and a grenade launcher located in the "mouth." Like the tanks in the series, it needs someone to take the locked protector covering off the mouth before it can start shooting explosives. The cockpit is typical and has the utilities seen in the series, like the monitor, sensors, etc. The only additions is that there's a pair of headphones, and the computer inside can now play audio CDs.
-Since Sera doesn't have a brain jack or a cyber brain, she can't access the network intercom used by the characters used in the series; that limits her to talking with someone right outside the cockpit. ((She might want to look into seeing if there's an off line intercom installed, or invest in some walkie talkies.))
-The Tachikoma is still fully capable of cloaking itself, using the adhesive wires, and cruising and jumping around. And as per the series, it has the personality of a child despite being a combat machine.
-To confirm, Sera has fully complied with Claire's terms of lease. The Tachikoma has not blown up anything in the apartment ((yet)) or shot at anything. ((Although Sera started getting the idea the Tachikoma could stay without any trouble when she realized that the apartment can take a speeding van, and make a walker tank sized hole in the process.))