Rechargeable LiPo Batteries 900mAh

The purpose of a LiPo battery is to store energy and release it at a desired time. This section examines discharging under different C-rates and evaluates the depth of discharge to which a LiPo Battery can safely go. The document also observes different discharge signatures and explores battery life under diverse loading patterns.

The electrochemical LiPo Batteries has the advantage over other energy storage devices in that the energy stays high during most of the charge and then drops rapidly as the charge depletes. The super capacitor has a linear discharge, and compressed air and a flywheel storage device is the inverse of the LiPo Batteries by delivering the highest power at the beginning. Figures 1, 2 and 3 illustrate the simulated discharge characteristics of stored energy.

Most rechargeable LiPo batteries can be overloaded briefly, but this must be kept short. LiPo Battery longevity is directly related to the level and duration of the stress inflicted, which includes charge, discharge and temperature.
Remote control (RC) hobbyists are a special breed of LiPo batteries users who stretch tolerance of “frail” high-performance LiPo batteries to the maximum by discharging them at a C-rate of 30C, 30 times the rated capacity. As thrilling as an RC helicopter, race car and fast boat can be; the life expectancy of the packs will be short. RC buffs are well aware of the compromise and are willing to both pay the price and to encounter added safety risks.

To get maximum energy per weight, drone manufacturers gravitate to cells with a high capacity and choose the Energy Cell. This is in contrast to industries requiring heavy loads and long service life. These applications go for the more robust Power Cell at a reduced capacity.

• Heat increases LiPo battery performance but shortens life by a factor of two for every 10°C increase above 25–30°C (18°F above 77–86°F). Always keep the LiPo battery cool.
• Prevent over-discharging. Cell reversal can cause an electrical short.
• On high load and repetitive full discharges, reduce stress by using a larger LiPo battery.
• A moderate DC discharge is better for a LiPo battery than pulse and heavy momentary loads.
• A LiPo battery exhibits capacitor-like characteristics when discharging at high frequency. This allows higher peak currents than is possible with a DC load.
• Nickel- and lithium-based LiPo batteries have a fast chemical reaction; lead acid is sluggish and requires a few seconds to recover between heavy loads.
• All LiPo batteries suffer stress when stretched to maximum permissible tolerances.

The energy stored in a battery, called the battery capacity, is measured in either watt-hours (Wh), kilowatt-hours (kWh), or ampere-hours (Ahr). The most common measure of battery capacity is Ah, defined as the number of hours for which a battery can provide a current equal to the discharge rate at the nominal voltage of the battery. The unit of Ah is commonly used when working with battery systems as the battery voltage will vary throughout the charging or discharging cycle. The Wh capacity can be approximated from the Ahr capacity by multiplying the AH capacity by the nominal (or, if known, time average) battery voltage. A more accurate approach takes into account the variation of voltage by integrating the AH capacity x V(t) over the the time of the charging cycle. For example, a 12 volt battery with a capacity of 500 Ah battery allows energy storage of approximately 100 Ah x 12 V = 1,200 Wh or 1.2 KWh. However, because of the large impact from charging rates or temperatures, for partial or accurate analysis, additional information about the variation of battery capacity are also provided by lipo batteries manufacturers.

Max Operating Voltage Range: 2.75V to 4.2V
Max Charge Voltage: 4.2V±50mV
Discharge Cut-off: 2.75V
Internal Impedance: <200mΩ
Expected Cycle Life: 500 cycles ≥ 80%

The voltage for long-time storage of Lithium polymer batteries used in the R/C model should be 3.6~3.9V range per cell, otherwise, otherwise it may cause damage to the battery.

Lithium polymer batteries packs also see widespread use in airsoft, where their higher discharge currents and better energy density compared to more traditional NiMH batteries have very noticeable performance gain (higher rate of fire). The high discharge currents do damage the switch contacts due to arcing (causing the contacts to oxidize and often deposit carbon), so it is advised to either use a solid-state MOSFET switch or clean the trigger contacts regularly.

The Standard LiPo Battery(Capacity below 3000mAh) ‘s max discharge current is 1C, and the max charge current is 0.5C, The standard charge current is 0.2C.
The standard discharge current is 0.5C

Standard LiPo Batteries Max discharge is 3A.
Max charge current is 2A.
High Rate LiPo Batteries depend on the C rate and PCM.

Lithium polymer batteries have a flexible, foil-type (polymer laminate) case, so they are relatively unconstrained.
Charge/discharge at 0.5C/0.5C, 80% residual capacity after 500 cycles.

Lithium polymer batteries provide manufacturers with compelling advantages. They can easily produce Lithium polymer batteries of almost any desired shape. For example, the space and weight requirements of mobile devices and notebook computers can be met. They also have a low self-discharge rate, which is about 5% per month.