I was running a pair of tenergy 2s 20c 5000mah together as a 10000mah for more runtime in my 4000kv tenshock powered slash 4x4. Well for more runtime and so I don't kill 2 good lipos cause the tenshock draws so much amps well run them paired for 200 amps of juice the batteries still got hot and desoldered one of the negative wires. That was after about 15 or 20 continuous laps. I noticed a big drop in power and the truck started to stutter on 1 lipo. I only ran 1 lap on a single 20c and I pulled it of the track and checked the voltage on the packs and they were both at 70%. The track is 60x100 so its not tiny but it's not huge. The power on 2 packs was great and the extra weight seemed to help with traction. I got my lipo fixed and I will be at it again and see how long it will actually run for.