Safety Of LiPo Battery Packs

LiPo battery features are frequently used in remote control automobiles. They generally charge quicker and store more energy than a similar NiCd power supply. However, LiPo battery power do require special managing. Neglect -- such as inappropriate asking for, managing, and storage -- can cause LiPo battery power to burn up or burst.

Handling a LiPo Battery Pack

Don't let children handle LiPo batteries. When transporting your LiPo batteries, use a non-flammable container that does not contain sharp objects that could puncture the battery packaging. Don't carry LiPo batteries in your pockets or throw them into your tool box. Don't place batteries -- especially damaged ones -- on flammable or hot surfaces. Don't handle damaged batteries with bare hands. If a damaged battery leaks on your skin, wash immediately with soap and water. After flushing with cool water, seek medical help if it gets in your eyes. When charging and using LiPo battery packs, keep a fire extinguisher or a bucket of sand nearby in case of fire. Do not try to put out a LiPo fire with water.

Charging a LiPo Battery Pack

Only use a charger that is designed for use with lithium polymer batteries. Also, only use a charger that can handle the specific cell count of your battery. While some chargers may be able to detect the number of cells automatically they could misread the battery. Others must be set manually. Doublecheck your settings for cell count and current no matter what type of charger you are using. Always read and follow the instructions that came with your charger and battery packs. Charging batteries should never be left unattended and should never be charged while inside your RC model.

Disposing of a LiPo Battery Pack

After fully discharging the battery, place it outside in a covered container of salt water (keep away from pets and children) for several days. Skip the discharging step and go straight to the salt water if the battery is ballooned or the covering torn. The discharged/soaked battery can now be placed into your household trash.

Using a LiPo Battery Pack

When operating your RC vehicles in or around water, make sure your LiPo battery is protected from the water. Don't immerse it in water or let it get wet. Make sure you don't have the positive and negative terminals reversed when operating your RC. Always inspect your LiPo battery after each use -- cleaning it if necessary. Always inspect your LiPo battery after a crash. Let it sit for an hour or so even if it appears to be OK. Do not continue using it if the packaging is torn or punctured or if you notice any ballooning of the battery. Continued use or charging of a damaged LiPo battery could result in an explosion and fire.
Storing LiPo Batteries

Make sure your rc battery packs is in good condition and partially charged before storing. Keep them in non-flammable containers, away from sharp objects or flammable materials, and at moderate temperatures. Store your LiPo batteries out of the reach of children. Don't store dead or damaged batteries.

RC Aiaplane Batteries, RC Battery

The latest rc battery technology is the LI-PO or Lithium Polymer battery. These RC batteries have the highest power to weight ratio and are the main reason why electric RC airplanes are so successful and popular. However they are different when compared to the Ni-Cd batteries we are all used to.

These Lipo batteries can't be charged using a Ni-Cd RC battery charger. Only use RC battery chargers specifically intended for use with the lipo battery. It is possible to start a fire if these RC batteries are mis-used. Always remove LiPo batteries from the airplane, prior to charging and place in a fire safe area.

A single lipo cell is nominally rated at 3.7 volts. The individual cells can be connected together, to form a battery, either in a series configuration or a parallel style. If we say the cells shown in the diagram are 2100mAh, the voltage of the series pack(4S) will be- 3.7Vx 4 cells=14.8 Volts. The capacity of this battery will be 2100mAh.

The lipo battery shown in a parallel configuration (4P)will have a voltage of 3.7V and a capacity of 2100mAhx4 cells=8400 mAh.

The series pack is known as a 4S pack and the parallel as a 4Ppack.(the number denotes number of cells and the letter denotes series (S) or parallel (P)).

If the series pack is doubled up and connected together in parallel it will be known as a 4S2P pack and will have a voltage of 14.8V and a capacity of 4200mAh. (2100 x 2 = 4200 mAh)

Another number you will come across when discussing lithium polymer batteries will be the "C"rating. This stands for the capacity rate of the RC battery. As an example you may come across 20C. Capacity is normally expressed as mAh (milliamp-hour) and there are 1000 milliamps in one amp. Thus a battery of 1000mAh can deliver 1A for one hour. If this same battery is rated at 20C then it can supply its 1 amp capacity up to 20 times higher, i.e. a maximum of 20amps can flow through it. However there is a price to pay in the form of duration. It can only supply this power for 3 minutes ( 1Ahx60/20=3 minutes).

If the lipo battery was 30C rated then current could be drawn through at up to 30 times higher ( 30A) but duration drops to 2 minutes ( 1Ahx60/30=2 minutes)

It is a good idea to be very conservative when it comes to batteries and use the cells at about half the claimed C rate. The risk of damaging the cells is considerably reduced and the number of re-charge cycles will be increased i.e the life will be longer.

The range of lithium polymer battery capacities and voltages is increasing daily.

If not you can make up your own packs. You must be able to solder and please keep the wires separate from each other. A short circuit can be very damaging to the cells and yourself. A further point when making batteries is-series packs can have cells of different voltage but the capacity must be the same. For parallel packs the voltage must be the same but the capacity can vary.