Archive forLiPo Batteries

Lithium Polymer Charging/Discharging Safety Tips

Lithium Polymer cells are a tremendous advance in battery technology for RC use. However, due to the chemistry of lithium cells, there is a possibility of fire if charging is not properly done. It is unavoidable due to the nature of lithium itself. This is no different from many things we use in daily life – knives, kitchen cleaners, automobiles, for a few examples – which are inherently dangerous, but which can be used safely by adhering to simple rules and precautions.
  • Batteries should NEVER be left unattended while charging.
  • Be absolutely sure that the lipo battery packs charger settings are correct for the battery pack being charged – both voltage and current settings.
  • Lithium Polymer must be CHARGED and STORED in a fire-safe container like a Lipo Sack.
  • Do not charge batteries near flammable items or liquids.
  • Keep a dry fire extinguisher nearby or a large bucket of dry sand, which is a cheap and effective extinguisher.
  • Never charge inside an automobile even when parked.
  • Keep Batteries Away from children and pets at ALL times.

Connection: Be sure that the correct polarity is observed when connecting battery packs to charger or ESC.RED = POSITIVE (+)


Charging/Discharging: Your new pack arrives half charged. Charge your pack fully before first use. Charge your LiPo battery pack at 5C or less on the LiPo setting only. You must use a balance charging system similar to the Hyperion chargers offered here at MaxAmps. Otherwise, you risk your pack becoming severely out of balance over time, which will significantly decrease the lifespan.Ex: If charging a 4000mah LiPo pack at 1C, you would be charging it at 4 Amps.

Ex: If balance charging a 4000mah rc battery lipo at 5C, you would be charging it at 20 Amps.

Please refer to your owner’s manual regarding the recommended ESC cutoff voltage for your particular application prior to first use to avoid accidentally over-discharging your batteries.

Do NOT charge your LiPo packs on a NIMH/NICD charger. Your charger must be designed for LiPo cells. Do not charge above 4.2V per cell, over discharge under 3V per cell. Never leave LiPo packs unattended during charging or after a crash in your vehicle. Don’t leave the battery pack plugged into a vehicle while not in use. The pack can still discharge to an unsafe level and damage the pack even if all components are turned off.

It is dangerous to draw more power than what the pack is rated for. This will void any warranty on the pack and can also cause your battery pack to ignite into flames. The temperature of the pack should never exceed 140F degrees. If it does, you may need a pack that is rated to handle more power.

Storage Procedure: When not using your LiPo/Life battery pack, store it at 60-70% of the pack’s rated capacity. Make sure to cycle your packs at least once per month since leaving them on the shelf for a prolonged period of time can cause the packs to get severely out of balance, puff/swell or even go dead.Balancing taps on LiPo/LiFe Packs: All MaxAmps LiPo/LiFe packs come standard with a JST-XH style balancing tap (white connector). This tap is compatible with all Hyperion balance chargers. Always balance charge your pack before each use as this “matches” the voltage of each cell to give you the highest performance and longest life.

Handling Cautions:

  1. Never leave batteries inside a car on a hot day or any other place where temperature may exceed 140F / 60C.
  2. Although environmentally friendly, lithium polymer cells must be FULLY discharged before disposal. Use a resistor setup (light bulbs, for example) to accomplish this, to avoid the possibility of a short-induced fire after disposal.
  3. Immediately discharge damaged batteries at 1/2 C rate and dispose.
  4. Do not put the loose cells in a pocket, bag, or drawer where they could short-circuit against other items, or the battery tabs could be pressed against each other.
  5. Do not place the loose cells on any conductive surface, such as a metal-topped table.
  6. We recommend purchasing pre-assembled packs rather than assembling packs from loose cells.
  7. Take care that the cells are not punctured, especially by metallic objects like hobby knives.
  8. If the electrolyte in the cells should get on your skin, thoroughly wash with soap and water. If in the eyes, rinse thoroughly with cool water. Immediately seek medical attention for this, or for burns.
  9. Although our batteries are now water sealed, we do not recommend submerging our batteries for extended periods of time. The battery packs will be protected during normal rc conditions.

All Lithium Polymer Batteries we carry are only approved for rc use, and may not be used in any other application. Battery discharging, charging, electric motors, spinning propellers, and flying models all have the potential for serious injury to persons and damage to property. In purchasing these products, the user agrees to accept responsibility for all such risks, and not to hold the battery manufacturer, distributors, or retailers - (all including owners and employees) -responsible for any accident, injury to persons, or damage to property.The use of Lithium Polymer batteries in radio-controlled models is to be considered experimental, and there is no warranty, expressed or implied, by the manufacturer, distributors, or retailers with respect to the capacity, life in cycles, storage, or discharge characteristics of lithium cells in RC use, nor any other use nor aspect unless otherwise stated.

This article comes from:


What You Need To Know About LiPo Batteries

What Are LiPo Batteries?

LiPo’s, or more correctly Lithium Polymer, batteries are the most common way today of powering electric RC models. Planes and helicopters are biggest beneficiaries of the development of LiPo quadcopter batteries because they are very light in weight compared to the amount of energy they can store. They also have high discharge rates compared to conventional rechargeable batteries (NiCad or NiMH) enabling them to provide the huge bursts of power required by high performance motors used in extreme flight manoeuvres. It is the innovation of the LiPo rechargeable battery that has enabled electric power to become so popular for RC helicopters, brought the cost down and opened the wonders of flying RC helis to a much wider audience who would never otherwise have entered the hobby.

When compared to their old NiCd/NiHm counterparts, lipo batteries rc have three main things going for them that make them the perfect battery choice for RC flight, all other RC hobbies as well as power tools or portable electronic equipment.

  1. RC LiPo batteries are light weight and can be made in almost any shape and size.
  2. RC LiPo batteries have large capacities, meaning they hold lots of power in a small package.
  3. RC LiPo batteries have high discharge rates to power the most demanding electrics.

These benefits are important in any function, but for RC airplanes and helicopters they are the reason electric flight has become so popular. Electric cars and boats have been around for decades, it wasn’t till LiPo battery technology arrived on the scene, that electric planes and helicopters started showing up and are rivaling nitro power in terms of performance.

LiPo RC Battery Ratings

There are a few numbers on LiPo batteries that you need to particularly look out for, which determine its rating and suitability for your particular model. The main ones are the batteries voltage (V), its capacity (mAh) and its discharge rate or ‘C’ rating.

Gens ace lipo batteries

Gens Ace Lipo Battery

Voltage or “S” Rating

LiPo battery packs are built up of cells each with a voltage of 3.7v. Those used in radio controlled helicopters, planes and the likes will normally be 1 to 6 cells each of 3.7v. LiPo’s will normally state the number of cells (S) but do not always show the voltage. So a 1S pack will be 3.7v, a 2S pack is 7.4v and a 3S pack 11.1v, right the way up to a 6S pack at 22.2v. Why is ‘S’ used to represent the number of Cells? Well it is the number of cells in Series and ‘C’ is used to represent the discharge rate. If there are a number of cells in Parallel this will be given a ‘P’ number, but other than very large capacity LiPo’s packs are usually 1P. So you might see “4S 2P” written on a LiPo, indicating that there are 2 lots of 3 cells in series hooked up in parallel.

Other than the smallest of electric RC models, RC LiPo battery packs will have at least two or more cells hooked up in series to provide higher voltages. For larger RC models that number can be as high as 6 cells and even more for larger birds or HV (high voltage) applications.

Here is a list of LiPo RC battery pack voltages with cell counts most beginners will be using;

3.7 volt battery = 1 cell x 3.7 volts (1S)
7.4 volt battery = 2 cells x 3.7 volts (2S)
11.1 volt battery = 3 cells x 3.7 volts (3S)
14.8 volt battery = 4 cells x 3.7 volts (4S)
18.5 volt battery = 5 cells x 3.7 volts (5S)
22.2 volt battery = 6 cells x 3.7 volts (6S)

Capacity or mah rating

Capacity indicates how much power the battery pack can hold and is indicated in milliamp hours (mAh). This is a way of showing how much load or drain (measured in milliamps) can be put on the battery for 1 hour at which time the battery will be fully discharged.

For example a RC LiPo battery that is rated at 1000 mAh would be completely discharged in one hour with a 1000 milliamp load placed on it. If this same battery had a 500 milliamp load placed on it, it would take 2 hours to drain down. If the load was increased to around 15,000 milliamps (15 amps) a very common current drain in a 400 sized RC helicopter while hovering, the time to drain the battery would be only about 4 minutes.

As you can see, for a RC model with that kind of current draw, it would be very advantageous to use a larger capacity battery pack such as a 2000 mAh pack or even higher. This larger pack used with a 15 amp draw would double the time to about 8 minute till the pack was discharged.

The main thing to get out of this is if you want more running time; increase the capacity of your battery pack. Unlike voltage, capacity can be changed around to give you more or less running time. Of course because of size restrictions and weight you have to stay within a certain battery capacity range seeing that the more capacity a battery pack has, the larger and heavier it will be.

Discharge Rate

The discharge rate is a very important specification to check when buying a battery. This number, also known as the battery C rating (or continuous C rating) defined how fast you can extract the energy from your battery. If your motors draw more energy that what you battery can provide, you can possibly damage your battery which can result in you crashing your drone. We discuss how to ensure the discharge rate is sufficient for your drone in our how to choose a LiPo Battery for your drone guide. To work out the actual current in Amps you simply multiply the capacity by the C vaue. So a 2200mAh battery with a C rating of 25C would have a continous current output of 25 x 2.2 = 55A continuous current output。

For more information about the huge selection of LiPo RC batteries available from Gens Tattu, or if you have any questions, please do not hesitate to contact us today. Discover why so many people come to us for industry-leading RC car batteries and “RC helicopter batteries”. We look forward to hearing from you.

Related Articles:


Next entries »