ProTek RC 2S "Supreme Power" LiPo 35C Hard Case Battery (7.4V/5500mAh)

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This is a ProTek R/C "Supreme Power" 2S 5500mAh, 35C hard case LiPo battery pack. This battery is built using a hard plastic case that is required for use at ROAR sanctioned tracks and events. The packs are thin enough to fit into all touring cars and off-road vehicles and can be used in any application where you need 6-cell NiMH stick or race packs. These packs are significantly lighter when compared to regular NiMH race packs for significantly improved acceleration and have dramatically reduced internal resistance. This leads to increased top speed and improved 'punch' off the line when compared to NiMH batteries.

Note: Some vehicles may require some re-balancing if the light weight of these batteries causes some handling changes. To get the vehicle to balance correctly, add weight to the battery side of the vehicle.

Unlike most other Lithium Polymer batteries, these batteries can be charged at up to 2 times the rated current, or 2C! If your charger is capable, you can charge these batteries at 10A!


Battery Model Supreme Power 35C
ROAR Approved Yes
Type Lithium Polymer
Capacity 5500mAh
Voltage 7.4V nominal
Connector Type
4mm Bullet
Balance Connector
2mm Bullet
Number of Cells 2 Cell
Configuration 2S2P
Dimensions (WxLxH) 46.7x137.5x23.1mm
Maximum Charge Rate 2C (11A)
Continuous Discharge 35C (192.5A)
Watt Hour
Weight 268g


  • (1) ProTek R/C Battery
  • (2) 4mm Bullet Connectors
  • (1) 2mm Balance Bullet Connector


1) DO NOT leave the battery in your model when charging
2) DO NOT leave unattended when charging
3) ALWAYS balance charge the battery
4) ALWAYS use a LiPo charging bag
5) YOU MUST use a Li-Poly specific charger to charge the pack (NiMH or NiCD only chargers WILL NOT WORK!)
6) YOU MUST not over discharge the Li-Poly battery pack
7) READ & UNDERSTAND the instructions carefully before operating this battery

NOTE: When using high energy Li-Polymer Batteries, please do not over-discharge or over-charge batteries as this will result in over heated batteries. Discharging capacity can't exceed 80% of the max capacity of the pack after full charging to ensure a good cycle performance. It is recommended to fully charge a brand new battery before using and only discharge the battery 50% for first 5 cycles. Always monitor race time and/or set a low voltage warning on ESC (End voltage cannot be lower than 3.2v per cell). Do not use the battery that has too low a voltage.

Do not expose batteries to sunshine or store/charge batteries at the temperature above 35°C or in a closed car. The high temperature environment could cause damage to the pack or make it burst. If the battery becomes hot while fast charging, high current discharging or racing, do not charge the battery until it has cooled completely. Wait about 20 mins, then inspect prior to recharging.

This product was added to our catalog on June 6, 2014

Verified Owner
Monday, Sep 7 2015 (about 4 years ago)
ProTek RC 2S "Supreme Power" LiPo 35C Hard Case Battery (7.4V/5500mAh)
These batteries are pretty good! However, out of 2 purchased, one seems to be puffing up (less than 3 months of use, about 30 cycles) a bit. Capacity and internal resistance are both holding steady, so I am going to let it go for now and keep an eye on it. Loads of punch and great capacity, though. I'd risk it and buy again.
Verified Owner
Thursday, Jul 25 2019 (10 months ago)
ProTek RC 2S "Supreme Power" LiPo 35C Hard Case Battery (7.4V/5500mAh)
Mine showed up completely dead as in zero volts through the balance port and Deans connector.
Verified Owner
Tuesday, May 30 2017 (about 3 years ago)
ProTek RC 2S "Supreme Power" LiPo 35C Hard Case Battery (7.4V/5500mAh)
I use this to power my Pro-Tek pit light. Works very well and lasts HOURS!! I would highly recommend, at least for this purpose...
Verified Owner
Tuesday, Jun 21 2016 (about 3 years ago)
ProTek RC 2S "Supreme Power" LiPo 35C Hard Case Battery (7.4V/5500mAh)
Superior service. fast shipping and when you call for any questions they have the answers