Source: www.rcheliresource.com

LiPo, or more correctly Lithium polymer, batteries are the most common way today to supply the electric RC models. Planes and helicopters are the greatest beneficiaries of the development of LiPo batteries because they are very light compared to the amount of energy that they can store. They also have a high rate compared to conventional rechargeable batteries (NiCad or NiMH) providing huge bursts of power required by high-performance engines used in extreme flight manoeuvre. It is the innovation of the battery rechargeable LiPo allowing electrical energy become so popular for helicopters RC, reduced cost and open the wonders of flying RC helis to a much broader audience who would never have otherwise entered the hobby.

For all their benefits, there are some disadvantages to LiPo; whether their relatively expensive, while having a life is quite limited. You must take care of them properly if you get even 300-400 cycles out of them. To do this you need a little knowledge on how to take care of them (see the article by the same author;) "(How the care for LiPo Batteries - see the link at the bottom of the page)." There is a degree of risk involved with LiPo, volatile electrolytes are known to ignite. It is not something that I would go, but it is something that you need to be aware of and must always keep in mind.

There are some figures on LiPo batteries you need particularly monitor, which determine its rating and suitability for your particular model. The main voltage (V) batteries, capacity (mAh) and its flow or a score of "C".

Thus, for the first of these - tension. LiPo batteries are constructed with a tension of 3 cells. 7V. those used in radio controlled helicopters, aircraft and people love it will be 1-6 of 3 cells. 7V. LiPo will normally be the number of cells (S) of State but do not always show the tension. Therefore a pack 1 will be 3. 7V, a 2 s pack is 7 4v and a pack of 3 s 11 1v, to the right the path to a pack of 6 22 2v. Why is ' used to represent the number of cells? Well, this is the number of cells in series and "C" is used to represent the flow. OK, "C" for the rate! A view! Well actually there is meaning in that the rate of discharge is a factor of the building cof the cell. All will become clear later. If there is a number of cells PARALLEL it will be given a number of 'P', but other than very high capacity LiPo packs are usually 1 P. So you could see "4 s 2 P" written on a LiPo, indicating that there are two lots of 3 cells in series connected in parallel.

The important but with a voltage thing is simply to ensure that you have good voltage LiPo of your model in particular. This will be determined by the combination of motor controller and the speed of the model. You simply follow that. So if it says you need a 11 1v 3 s LiPo, you get exactly that for your model. The rate of capacity and the discharge of the LiPo may easily vary but the tension must be right.

Which then leads nicely to deal with capacity of LiPo. This is usually given in mAh (milliamp hours). It quantifies milliamps how you could drain it at a constant rate for an hour to fully complete the pack. So if you could run a LiPo to 2200mA hour capacity would be 2200mAh and it would have twice the capacity of a LiPo which could run only 1000mA for one hour to completely it drain of fully loaded. It's like the size of the fuel tank in your car. It is clear that made Beaver the capacity of your tank of fuel, or LiPo battery, you can run to. With radio controlled models, mostly RC helicopters and airplanes, the factor limiting is the weight and size of the battery. Largest capacity bag can give you more long flight time but being heavier, that it will negatively affect performance.

Now for the discharge of speed (C). As noted before the "C" is related to the capacity and here's how. The c number represents the number of times faster that the strengthening cyou can pay the pack safely at a constant speed. For a LiPo 2200mAh with a rating of 20 C can be released safely at up to a load of 44000milliamps (44amps). From there, you can also determine how long it would take to completely release the pack for that load. Given that the ability of a pack is quantified in milliamps how need to completely discharge in one hour, the time it takes to drain at the speed c will be 1 hour or 60 minutes, divided by the value C. Therefore a pack 2200mAh with a rating of 20 C discharge in 3 minutes. In practice never consistently apply us something like these levels of release to the flight of time much longer.

Many packs will show now two-digit capacity, for example 20 C and 40 C. The first represents the above constant flow and the second of the "burst rate". As you can imagine name burst rate refers to the rate of short bursts.

There are a number of factors to keep in mind when selecting the rating c for your batteries. First note that in General, pleased the flow rate the higher the LiPo, although the difference becomes less. Second, you can use one that is too low; which would make your pack and most probably harm ESC. For beginners and light sport or flyers with RC helicopters to scale up to a 450 size 20-25 C is ample. When you start doing more aggressive 3D maneuvers or larger helicopters, you will need to look up to 35 - 45 C Note: progression packs. The best advice is that if you can afford to do so, you should go a little more that what you need. A LiPo pack running near its limits will be hot and this reduces its lifetime. You can pay more for a more generous c rating, but it is likely that last you longer. A tip here is to test the temperature of the landing immediately after of your LiPo. If it is too warm comfortably hold firmly between your hands the pack is more too hot. This means that you need a more C Note: pack or your backpack is old and in need of replacement.

So in summary, the main factors to consider when choosing LiPo is:

• the voltage (V) good for the combination motor/ESC in your model, determined by the number of cells (S) in the LiPo pack
• capacity (mAh), which will give you optimal flight time without compromising the performance of choice
• the rate of discharge (C) you need to take into account the load on the pack by the engine and the weight of your model and flight level will be undertaken.

You will probably find recommendations with your model for the first two of these (V/S and mAh) leaving allows you to determine the last (C) for yourself and if you follow the instructions above you will not go far wrong.