COMBAT ROBOTICS

BATTERIES AND CHARGERS

COMBAT ROBOTICS BATTERIES

Robots can use plain old 9V batteries. In fact, the Viper Robot Kit comes with a 9V option. Amazon basics 9V batteries But in general, most bots by far use Lithium Polymer (LiPoly) combat robotics batteries to power their bots.  LiPoly batteries are the battery of choice because of their cost, power capacity, and power to weight ratio.  LiPoly batteries must have a charger designed specifically for LiPos and they require specific maintenance to avoid dangerous conditions.  See “LiPo Safety” Below. Battery Terminology:
  • 400mAh: mAh = “milliamp-hours.”  This is a measure of how much current the battery can provide per hour. For example, the 400mAh batter can provide 400milliamps (0.4 amps) per hour or 4 amps for 1/10 hour (6 min- more than a match!
  • 3S: “S” is the number of cells in the LiPo, so 3S is a battery with 3 cells. Each cell can deliver a nominal 3.7v, so a 3S delivers 11.1v.
  • 10C: Occasionally a battery description will also include a C-number. C defines the continuous safe current draw of the battery. In this case, 10C is 10 x 400mAh or 4000mA (4 amps). If the bot exceeds the maximum safe continuous current draw, the battery runs the risk of burning out or bursting into fire.

IMPORTANT NOTES ABOUT LITHIUM POLYMER (LIPO) BATTERIES.

  • Lithium batteries are a great innovation for many things. However, as you may have seen in the news, LiPo batteries can release their stored energy suddenly, causing fires.
  • Store the batteries between matches in a LiPo storage bag. Many are available from Amazon.
  • If your LiPo charge falls below 3.3v per cell, it will not be safe to recharge. So, for a 2S battery, the minimal voltage is above 6.6v. A 3S battery must be kept above 9.9v. If your robot begins to slow down, recharge the bot.
  • You can also purchase a Low Voltage Alarm that plugs into the white balance plug of the battery. It displays the pack voltage and will sound an audible alert when it is time to recharge.
  • If a pack is ever damaged or seems puffed up, don’t try to charge it. Replace the pack and recycle the old one. Charging damaged or puffy batteries can cause a fire.
  • You can also purchase a Low Voltage Alarm that plugs into the white balance plug of the battery. It displays the pack voltage and will sound an audible alert when it is time to recharge.
  • A lipo charger for your battery is required. It is not included in our basic kits because many robot builders already have LiPo chargers, but every kit comes with an option to purchase a charger.

 

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