Class 4 article

9V (later marketed as the Electric System or the 9V-powersystem, depending on country) was a voltage standard for electrical components (e.g. motors, lights) in many LEGO sets. It first appeared in 1985 in the Light & Sound series of Town and Space models that featured flashing lights and sirens, and was later expanded to the Monorail sets.

TECHNIC also moved over to the 9V system in 1990, with Trains making the change the following year.

The power came from a battery box with one 9V PP3 type battery (e.g. or later with 6x 1.5V batteries (TECHNIC, Basic). The 9V system sought to address the major weakness with the preceding 4.5V and 12V systems which was the pinned plug connectors that were prone to coming loose or the wires that would eventually fracture and fail after heavy use. The new system used special bricks that contained conductive elements built into the studs which were connected more positively and were more reliable over long periods of use. Wired connections were still used whenever power had to be transmitted through awkward routes, but the terminations used the conductive brick connectors in place of the pinned plugs.

The Trains theme was the only application of 9V that was powered by a mains DC Transformer and special metal conducting rails for 9V Trains (without any add-on centre conductor rails that were used by the earlier 12V Trains system). Controversially however the 9V Trains system lost most of the accessories of the 12V system such as remote controlled signals, points and lights.

9V powered Themes

9V powered Sets






Service Packs

Complete List

Image#SetNumber of piecesMinifiguresPriceRelease
0005-1 x 2 Lamp Brick 9V.jpg00051x2 Lamp Brick, 9V2$10.002008
10002-1.jpg10002Railroad Club Car2885$37.502001
10013.jpg10013Open Freight Wagon121$17.002001
My Own Train 10014 Caboose.jpg10014Caboose170$14.992001
10015.jpg10015Green Passenger Wagon194$19.992001
Octan Tanker.jpg10016Tanker128$19.992001
10017.jpg10017Hopper Wagon228$20.002001
10020-1.jpg10020Santa Fe Super Chief4352 (1 railroad worker and 1 mechanic)$40.00 / €34.992002
10022.jpg10022Santa Fe Cars - Set II411$35.002002
10025.jpg10025Santa Fe Cars - Set I326$35.002002
10027-1.jpg10027Train Engine Shed6642$70.002003
10078-Train Connection Wire.jpg10078Train Connection Wire1 2003
10128-1-1.jpg10128Train Level Crossing327Construction Worker, Conductor Charlie$49.992003
10132 boxart.jpg10132Motorized Hogwarts Express708Harry Potter, Ron Weasley, Professor Lupin, Dementor 2004
10133-1-1.jpg10133Burlington Northern Santa Fe Locomotive4072$39.992004
10153.jpg101539V Train Motor3$25.002002
10157-1-1.jpg10157High Speed Train Locomotive1432$24.992004
10158-1.jpg10158High Speed Train Car161Undercover Cop, Person 2004
10170-1-1.jpg10170TTX Intermodal Double-Stack Car366 2005
10173-1.jpg10173Holiday Train965Engineer Max, 2 Train Workers, 4 People$89.992006
10205 My Own Train.jpg10205My Own Train232 2002
2126-1.jpg2126Train Cars3785$69.501997
2150-1.jpg2150Train Station599Chef, 7$73.001996
2159-1.jpg21599V Train Track Starter Collection24$29.992006
2585-1-1.jpg2585Track Buggy with Station Master and Cool Kid322 1998
3225-1.jpg3225Classic Train2813 1998
3740.jpg3740Small Locomotive67$15.002001
3741.jpg3741Large Locomotive92$19.992001
3743-Locomotive Blue Bricks.jpg3743Locomotive Blue Bricks106$6.992001
3744-Locomotive Green Bricks.jpg3744Locomotive Green Bricks1060$6.992001
3745-Locomotive Black Bricks.jpg3745Locomotive Black Bricks106$6.992001
3746-Locomotive Brown Bricks.jpg3746Locomotive Brown Bricks106$6.992001
3747 Locomotive Grey Bricks.jpg3747Locomotive Dark Grey Bricks106$6.992001
3748.jpg3748Light Unit for Train4$9.992001
4186875-1.jpg4186875Platform and Mini-Figures475 2002
4186876-1.jpg4186876Blue Passenger Wagon192 2002
4206-1.jpg42069V Train Switching Track Collection27$44.992006
4223 brickset.jpg4223Challenger Set 400 with Motor546 1999
High speed train.jpg4511High Speed Train3363 2003
4512.jpg4512Cargo Train5443$140.002003
4513-1.jpg4513Grand Central Station3545$49.992003
4514.jpg4514Cargo Crane1752 2003
4515 Straight Tracks.jpg4515Straight Rails8$13.251991
4519-1.jpg4519Rail Crossing1$10.001999
4520 Curved Tracks.jpg4520Curved Rails8$13.251991
4520.jpg4520Curved Rails for 9V Trains8 1999
4525-1.jpg4525Road and Rail Repair811 1994
4531 Switching Rails.jpeg4531Manual Points with Track6$28.001991
4532-1.jpg4532Manual Level Crossing1351$24.001996
4533 Snowplough.jpeg4533Train Track Snow Remover581$9.001999
4534.jpg4534LEGO Express345$159.992002
4535.jpg4535LEGO Express Deluxe762 2002
4536 Box.jpg4536Blue Hopper Car166$15.001991
4537-1-1.jpg4537Twin Tank Transporter1741 1993
4539-1.jpg4539Manual Level Crossing1101 1991
4541-1.jpg4541Rail and Road Service Truck1222$14.251999
4543-1.jpg4543Railroad Tractor Flatbed1781 1991
4544-1.jpg4544Car Transport Wagon with Car1431 1994
4546-1.jpg4546Road and Rail Maintenance771$10.001991
Set4547.jpg4547Club Car2935$37.501993
4548 Electric Train Speed Regulator.jpg4548Transformer and Speed Regulator3$42.001992
4549-1.jpg4549Container Double Stack4512 1993
4551-1.jpg4551Crocodile Locomotive3141 1991
4552-1.jpg4552Cargo Crane2822 1995
4553 Box.jpg4553Train Wash1852$30.001999
4554-1-1.jpg4554Metro Station5648$72.001991
4555-1.jpg4555Cargo Station3893$66.001995
4556-1.jpg4556Train Station2367 1999
4557-1.jpg4557Freight Loading Station2152 1999
4559 Box.jpg4559Cargo Railway8427$139.001996
4560.jpg4560Railway Express6589 1999
4561-1.jpg4561Railway Express6659$139.001999
Set4563.jpg4563Load and Haul Railroad4763 1991
4564-1.jpg4564Freight Rail Runner5873$134.001995
4565-1.jpg4565Freight and Crane Railway9143 1996
5011.jpg50119V Basic Motor1$27.001993
5040.jpg5040Monorail 9V Motor for Space Track1 1989
5114.jpg5114Technic Motor 9V1$16.001990
5115.jpg5115Technic Battery Box 9V1$11.001991
5120-1.jpg5120Polarity Reversal Switch for 8082 (9V)2$5.501993
5293-1.jpg5293Battery Box - Basic and TECHNIC1$12.251996
5300.jpg5300Train Motor 9V3 1991
5302.jpg5302Bogieplates, Black20$1.991992
5307-1.jpg5307Head Light Brick3 1992
624 Box.jpg624Basic Motor, 9V27$26.001996
6430 Box.jpg6430Night Patroller140Police Officer 1991
6440 Jetport Fire Squad.jpg6440Jetport Fire Squad159Firefighter (x2) 1991
6450.jpg6450Mobile Police Truck771 Police Officer$18.751985
6480-1.jpg6480Hook and Ladder Truck1181 Fireman$23.001985
6481 Construction Crew.jpg6481Construction Crew1682 1989
6482.jpg6482Rescue Helicopter1983 1989
6483.jpg6483Coastal Patrol243Police Officers (x3)$47.991994
6484-1.jpg6484F1 Hauler269Mechanic (x2), Ben Steer 1995
10132 brickset.jpg65524Hogwarts Express Co-Pack704Dementor, Harry Potter, Professor Lupin, Ron Weasley 2004
65537-Classic Freight Train.jpg65537Classic Freight Train613$80.002004
65801-1.jpg65801Trains Value Pack7355 2005
6750 Box.jpg6750Sonic Robot103Blue Classic Spaceman, Spaceman Reed 1986
6770 Futuron.jpg6770Lunar Transporter Patroller118Yellow Futuron Astronaut$26.751988
6780 Light & Sound XT - Starship.jpg6780XT Starship201Yellow Classic Spaceman 1986
6990 Box.jpg6990Monorail Transport System715Blue Futuron Astronaut (2), Yellow Futuron Astronaut (3)$155.001987
6991 Box.jpg6991Monorail Transport Base573Unitron Chief, Unitron Astronaut (x2), Major Kartofski$178.001994
0735-1.jpg735Basic Building Set537 1990
8064 Universal Motorized Building Set.jpg8064Motorized Universal Building Set219$54.991990
8082 UBS.jpg8082Multi Model Control Set459€69.991993
0845-1.jpg845Battery Motor, 9V27 1992
846-box.jpg846Lighting Set, 9V39$17.991992
8720-1.jpg87209V Motor Set57$35.991990
8868-1-1.jpg8868Air Tech Claw Rig954$139.991992
9203-1-0.jpg9203Deluxe Lighting Kit  1993
970005-9-Volt 1 x 2 Lamp Brick.jpg9700059-Volt 1 x 2 Lamp Brick2 2002
970041-128 MM Connecting Leads.jpg970041128 MM Connecting Leads3$9.702002
K10173-1.jpgK10173Complete Holiday Train Collection9977 2006
K2159-1.jpgK2159Holiday Train Starter Collection9917$165.992006
K4548-1.jpgK45489-V Train Accessory Collection22$96.972007