I copied/pasted the TCS general battery rules below
ARTICLE 5: BATTERIES
5.1 Any ROAR approved Lithium-Polymer (Li-Po) battery may be used, for any TCS class. Check the ROAR approved Lithium-Polymer (Li-Po) battery list here:
http://www.roarracing.com/approved_lipo_batteries.php
5.2 Sport Ni-Cd and Ni-MH batteries are legal, for TCS racing. These batteries do not need ROAR approval.
5.3 TCS legal Lithium-Polymer (Li-Po) must be 7.4/7.6 volts, 2S-2P specification. NOTE: Despite the ROAR approved list, Sport Packs (round HARD case Lithium-Polymer (Li-Po) batteries) may be used on Tamiya models where only a round case battery will fit. This type of battery does not need to be ROAR approved.
5.4 LIPO Battery TECH rules: In the interest of safety, and fairness, all LIPO batteries will be volt metered during TECH Inspection. LIPO batteries exceeding 8.44 volts (2S packs) will not be allowed to race on the track, until they have been discharged to meet the 8.44 rule. 5.5 All battery packs may not exceed 10 degrees above ambient temperature. You will not be allowed to race with “HOT” battery packs.
5.6 All LiPo batteries must be charged in a LiPo sack, at all TCS events!
5.7 Any type of battery connector is permitted to be installed on your battery pack.
Here are the Eurotruck rules
ARTICLE 16: EURO-TRUCK
This is a pure box stock class open to any skill level hobbyist.
Recommended Minimum Skill level: Novice, Intermediate to Advanced
16.1 Legal kits: Item 58632 Team Hahn Racing MAN TGS, 58642 Team Reinert Racing MAN TGS, 58661 Buggyra Racing Fat Fox, and 58683 Tankpool24 Mercedes Actros
16.2 The kit must be built EXACTLY per the instruction manual.
16.3 The ONLY Hop-Op Options permitted are Ball Bearings (ANY BRAND), and any Tamiya servo saver.
16.4 Must use the stock pinion and spur gear.
16.5 Must use the kit supplied Tamiya TBLE-02S/TBLE-04S ESC/THW-1060 Brushed Motor ESC (2-3S) Hobbywing OEM-Same as QUICRUN 1060 BRUSHED ESC (2-3S).
16.6 Must use the kit supplied motor (item 54358 RS-540 Torque-Tuned Motor)
16.7 Battery connector on ESC may be changed to DEANS type or XT-60.
16.8 The Motor Bullet Connectors may not be removed.
16.9 The ESC & Motor wires may not be shortened, or removed!
16.10 All polycarbonate body parts must be used.
16.11 All screws in the kit must be used. You may not omit screws to change the handling of the truck.
16.12 Minimum weight: NONE. No weights, of ANY KIND, may be put on the truck for ballast.
16.13 Adding FOAM material to the kit foam bumper is permitted. You may also use item 54819 Urethane Bumper XL in place of the stock size bumper.
16.14 Tires: Must use kit type tires, and wheels.
16.15 Any grease, or lube may be used to lubricate gears, or moving parts.
16.16 Any Tamiya Hi-Torque Servo Saver is Permitted.
16.17 It’s permitted to mix & match front/rear wheels on the truck for durability.
16.18 Batteries: Any stick-pack type, hard round case LiPO, NiCD, or Ni-MH is permitted. Examples: Reedy Wolf-Pack, or Peak Racing Powermax batteries.