This is the ProTek R/C 4S 2100mAh, 20C Lithium Polymer battery pack. This pack has T-Style Ultra connectors pre-installed, and comes with a 5-pin Align/E-Flite style balance connector.
This battery will also make an excellent starter box battery for R/C Cars! You can significantly reduce the weight of your starter box, as one of these batteries will weigh less than one third of two 3600mAH NiMH packs (221g vs 802g). This will make your starter box almost 1.3 pounds lighter! Not to mention they will have increased voltage and punch, making it easier to start a tight engine.
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 up 4.2A!
CRASH Protection Guarantee!
This battery pack is covered by the ProTek R/C manufacturer "Crash Protection Guarantee"! If you crash your vehicle, helicopter or airplane badly enough to damage the battery pack, you can send the damaged battery pack back to A Main Hobbies and purchase a replacement battery for 50% off the regular sale price!
IMPORTANT: 1) You will need a Li-Poly specific charger to charge the pack (NiMH or NiCD only chargers WILL NOT WORK!) 2) You must not over discharge the Li-Poly battery pack. 3) Read 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.