Battery Charging

We (Student Robotics) manage the charging of all batteries at the competition. Battery Charging volunteers are responsible for ensuring that there is a continuous supply of charged batteries available for use by teams.



Most batteries and chargers will arrive with teams, but any batteries, bags, and chargers in inventory should be prepared during setup. Please only set up the blue 'IMAX B6' chargers, as it simplifies the charging role to have only one type of charger.

There are two locations involved in battery charging. The equipment required at each is as listed below:

  • Helpdesk
    • 1 x Discharged Battery Box (18L RUB), clearly labelled
    • 1 x Charged Battery Box (18L RUB), clearly labelled
    • 1 x LiPo Bag for damaged batteries, clearly labelled, red taped
    • At least one roll of red insulating tape
  • Battery Charging Station
    • 1 x Discharged Battery Box (18L RUB), clearly labelled
    • 1 x Charged Battery Box (18L RUB), clearly labelled
    • 1 x Damaged battery box (18L RUB), clearly labelled, red taped
    • At least one roll of red insulating tape
    • A Radio for contacting the health and safety officer
    • Example good batteries (one brand new, one squidgy)
    • A copy of this document

Safe Use of Battery Charging Equipment - Battery Charging Station

  • There should be 0.5A of mains electricity available per charger
  • It should be ensured that any power distribution is setup properly and able to handle the current draw
  • Additionally, there should be no trailing wires across the floor to prevent charging batteries falling on the floor

Volunteer Requirements

Every volunteer performing the Battery Charging role must have read this document fully. Any doubts must be raised with the person who briefed you. If you weren't briefed, speak to the volunteer manager.


The biggest risk of damage or injury is from the banana plugs coming unplugged from the charger. These are the red and black plugs that go into the side of the charger. All of the chargers should have the cables cable-tied to the charger to make it difficult to remove these plugs. Under no circumstances should these red and black plugs be unplugged from the chargers.

The batteries themselves have many built-in safety features and, unless abused, are completely safe. All batteries undergoing charging must be placed inside a fireproof charging bag. In the extremely unlikely event of a fire due to a battery:

  • DO NOT use a fire extinguisher - the batteries contain hazardous materials which cannot be safely tackled by most fire extinguishers.
  • DO NOT open or attempt to remove anything from the charging bag.


  • A fire bucket full of water will be supplied, get the battery into the bucket. This should be performed complete with the charging bag, and any other contents of the charging bag. This battery must not be removed from the bucket.
  • Remove power from all other batteries and chargers, and move all undamaged equipment away from the faulty battery/charger.

If a fire does occur, regardless of if the aforementioned steps are possible, trigger the fire alarm and initiate an evacuation.

If at any point you have any doubts about safety, immediately summon the Health & Safety officer over the radio.


Swapping a team's battery - Helpdesk

Teams will bring discharged batteries to helpdesk and require a replacement charged battery. A Battery Charging volunteer should receive the discharged battery from the team and place it a battery bag in the discharged battery box. A charged battery should be removed from a battery bag in the the charged battery box and handed to the team.

Do not allow teams to take batteries themselves - we want to prevent them from hoarding batteries. Batteries must only be swapped - don't give a battery unless we receive one in return.

Swapping batteries - Shuffling

One of the volunteers that is running the battery charging station will periodically have to go and get discharged batteries from the helpdesk, simultaneously dropping off charged batteries. Helpdesk may also contact them over radio to do it sooner.

The general schedule will go as follows:

  • Charged batteries should be taken to the helpdesk and put into a fire-proof bag in the charged batteries box.
  • Discharged and damaged batteries should be taken from the fire-proof bag in the discharged batteries box to the battery charging station.
  • Any batteries that were marked as damaged by the helpdesk (using red tape) should be inspected and placed into their own fire-proof bag in the damaged battery box if they are damaged.

Charging a discharged battery - Battery Charging Station

It's important that the battery charging station should never be left unsupervised. For this reason, we assign this role to 2 volunteers if the battery charging station isn't right next to helpdesk.

If you want to be in the group photo on Sunday, please make sure you disconnect all batteries and leave them in their fire-proof bags before leaving the position.

All of the battery chargers will be set-up and ready to use. Before a battery is connected, the screen must display LiPo BALANCE 2.2A 11.1V(3S). If it displays anything other than this, please do not use it and contact helpdesk.

Batteries are charged as follows:

  1. Check that the battery is not physically damaged. There should be no splits or tears in the body of the battery, no nicks in the wire insulation, no exposed wire and the battery should not be so swollen that it is no longer squidgy. There will be a couple of example batteries at the Battery Charging station to compare to.
    • if the battery is damaged, tape over the yellow XT60 connector with red tape and place it in the damaged battery box.
  2. If the battery is not damaged, plug the yellow XT60 connector into the charger cable and the white balance connector into the 4-pin socket on the side of the charger.
  3. Place the battery in the charging bag next to the charger.
  4. Hold down the Start/Enter button for about 3 seconds until the screen displays R:3SER S:3SER CONFIRM(ENTER). If both numbers are not 3 then disconnect the battery and summon the Health and Safety officer.
  5. If the display is as expected, press Start/Enter to commence charging. After about 1 hour the battery should complete charging - the screen will display a charge complete message. Simply disconnect the battery from the charger and place it in the charged battery box.

If at any point throughout the charging cycle the charger indicates an issue (e.g. a timeout, capacity or cable error), disconnect the battery from the charger, apply a piece of red tape to the yellow XT60 connector on the battery and place it in the damaged battery box. Inevitably there will be a small number of faulty chargers. If you suspect that a particular charger is faulty (lots of batteries fail to charge on it), disconnect it from its power supply, apply red tape to its yellow XT60 connector and place it in the damaged battery box.

Discharging batteries

At the end of an event batteries should be discharged. The process for this is identical to the charging process except the mode should be changed to "Storage" by pressing the Inc/Dec buttons prior to pressing Start/Enter.

Some damaged batteries may be able to be safely discharged to render them inert before they are disposed of. Check with a member of the Kit Team before doing this. In this instance change the mode to "Discharge".


This page is based on work done by Richard Barlow, originally published at, which was under the Creative Commons Attribution-ShareAlike 4.0 International License. To view a copy of this license, visit or send a letter to Creative Commons, PO Box 1866, Mountain View, CA 94042, USA.