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Words: Donald
Natale, Add-on*: Arn0 What everyone should know about the Use and Care of Lithium Polymer (LiPo) batteries. What size of voltage battery should I use, 3.7, 7.4 volts, 11.1 volts or higher? Be sure to check your ESC's (electronic speed control) allowed voltage input from the specifications in the supplied manual that you received when you purchased the speed control. Remember higher voltage means the motor can generate more speed however; the more heat is also produce. What is the difference between a one, two or three cells lipo battery? The
primary difference is voltage! A single cell or (1S) Lipo is 3.7 volts,
2-cell or (2S) Lipo is 7.4 volts; 3-cell or (3S) is 11.1 volts. What does the C rating mean on Lipo batteries, example: (10C, 20C, 35C etc.)? “C”
rating is the allowable amp draw of the battery. It relates to discharge
limits of the Lipo battery. The higher “C” number means that the
battery is capable of taking a higher discharge load without causing
damage to the battery. I see 180mah, 2000mah, 3600mah, ect. What does “mah” stand for? MAH is the (Milli Amp Hours); this is the capacity or run time of the battery. The higher the milli amp capacity 2000, 3600 and so on equates to how much run time the battery will have. Be sure that you check the motors temperature during the first run for proper gearing. Incorrect gearing will over heat the motor and could cause irreversible damage.
What is 2S2P! 2S2P...Means there are two cells (2) in series (S) (which makes 7.4 volts) and two (2) in parallel (P) to get capacity. If you were to add another cell in series that would increase the (S), number to and would raise the capacity from 7.4v to 11.1v at that time you would have a 3S2P battery, and that number can increase even more depending on how many cells are added to the pack. I see batteries on the market and some say TX or RX even though they may have the same specifications. TX = (Transmitter) and RX= (Receiver) each uses different voltage batteries. Typically, an RX 2-cell is no more than (7.4 volts) and TX is (11.1 volts)... plugging in a11.1-volt battery into your RX could cause a catastrophic failure unless you have a voltage limiter also connected. Depending on the specifications of your receiver, you may need to run a voltage limiter with your RX when using higher voltage battery, a typical RX runs up to 6.0 volt, but that does not mean you cannot use higher voltage batteries, just be sure to check with the manufacture on the receiver’s capabilities.
Do I need to balance my Lipo batteries? YES, if the battery goes out of balance they have higher chances of failure since the packs are sensitive to overcharging and discharging. Your Lipo battery pack will have either a balancing port or a balancing connector; you may need to purchase an optional balancer like the (LRP Precision Parallel LiPo Balancer #LRP45200) unless your charger is capable of balancing Lipo batteries as well as charging them. NOTE: A balancer keeps the voltage in your cells equal, which helps to keep the battery from over discharging or overcharging and helps produce the best performance from the battery. Using a balancer during the charge sequence is very important, overcharging a cell can cause it to spontaneously swell and quite possibly explode. A balancer will remove this risk factor however, as with anything Lipo, so take caution and read the manufacture usage instructions before using your battery. Do 3-cells or more take more time to maintain? Nope, it does not take any more time to maintain any size lipo battery is just common sense and that is your greatest tool. Unfortunately, people who do not take care and follow the rules set by the battery manufacture are to blame for Lipo related disasters due to incompetence. A voltage limiter or voltage cut-off, is this needed in Lithium Polymer applications? The limiter is actually a voltage cut-off specifically designed so you can use Lipo type batteries with older receivers and speed controls that are not Lipo compatible. When using Lipo as a receiver pack or when using Lipo batteries with older version speed controls, it is to prevent the battery from discharging to low during use. The cutoff is usually around 6.25v or 3.125 volts per cell. Once a Lithium Polymer battery discharges below 3.0 volts per cell, there is less likely chance that you will be able to get it to recharge again. Storage: If you do not plan to use your lipo pack for longer than a week, store it at 50-60% of the pack’s rated capacity. Make sure to cycle and/or balance your packs at least once per month since leaving them on the shelf for a prolonged period can cause the packs to get severely out of balance or even go dead. Lithium Polymer Safety Tips: Lithium Polymer cells are a tremendous advancement in battery technology for RC use however, due to the chemistry makeup of the lithium cells; there is a possibility of fire if not used properly! It is unavoidable due to the nature of lithium itself (see details). 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 and are used safely by adhering to simple rules and precautions. Example: It is best not to run motors until they reach 100 degrees Centigrade or 212 degrees Fahrenheit this could damage and could cause a battery to overheat. On the other hand, by overcharging the battery with incorrect charger settings, and or by over discharging the battery…Each of these scenarios can be the cause of a battery failure! Charging
Precautions:
Handling
Precautions: Should I try to fix a Lithium Polymer battery that has been damaged? Lithium
Polymer batteries that has become damaged by puncture or over
discharging or by over charging beyond the recommended limits and the
pack has sings of leaking or swelling, it is NOT RECOMMENEDED that you
try to fix or repair the battery. To dispose of Lipo cells and packs:
If you are disposing of Lipo batteries/cells:
Don
Natale *Add-on = Lithium link |
