For most drone newbies, it is very important to know how to choose a Lipo battery for your drone; but drones is a great lesson, you need to know too much knowledge like motors, ESC, wings, Lipos and so on. And this article is help you to know how to choose a lipo battery for your drones, and you must to know some Lipo knowledge before read this post.
Where to Start
Well first know the weight and class of you quadcopter. The smaller your quad the smaller you battery and the lower C it can be. Here is a rough guide:
|Class of Quad||Number of Cells||Capacity (Mah)||Discharge rate (C)|
|Racing 5” props||3-5S||1000-1500mah||75+C|
|300 GT quads||3-5S||1800-3000mah||40-65C|
There is an Idea of what type of Battery to go for;
And you can check the Quadcopter frame, lipo battery, motor and propeller size matching table;
Battery Discharge Rate and Capacity
Alright lets start by saying that C rating it basically Bulls**t. Companies like Gens Ace&Tattu quote 95C on some of their batteries, in other words supposedly you could completely discharge a battery in 30 seconds without any permanent damage, this is crap and neigh on impossible. However, C rating does matter, the point we are trying to make is don’t take whats on the label as Gospel and should be taken a rough guide only to a LiPo packs capabilities. We still maintain that the the best way to tell a LiPo’s quality is through community feedback.
Using a discharge rate (C rating) that is too low, can result in your battery being damaged, and your drone under-performing the battery can’t release current fast enough to power your motors properly. This results in something known as Voltage sag. Put simply when you ESCs try and pull a large amount of current the voltage of the battery drops because of internal resistance, meaning you quad effectively looses power. However there is a flip side since higher C rating batteries are heavier, if the battery you are using has a C rating that is too high, you will just be carrying extra weight around that you dont need, ultimately reducing the flight time.
How to calculate the maximum continuous current output for your battery?
- Max continuous Amp draw (A) = Battery capacity (Ah) x Discharge rate (C)
How much capacity do I need? Alright so there are two big pros to have a larger capacity:
- it can give you more amps (see equation above).
- It will give you longer flight times
However there is one massive floor. IT’S MORE WEIGHT. This means your quad will be
- Less agile
- Break more easily in a crash due to more momentum (=mass x velocity)
Battery Voltage (cell count)
Higher voltage batteries allow your motors to produce more power, however the higher voltage batteries are heavier since they contain more cells.
There is no optimum to follow when it comes to battery voltage, but the way you can find the best voltage for your drone is to look through your motor thrust data tables and compare the efficiency. You will find that motors are generally more efficient and powerful when using higher cell count Lipos (higher voltage), but some of the efficiency bonus is negated by the increase in weight and cost of the battery.
As a general rule of thumb: Higher cell count for larger motors with lower KV and Lower Cell count for smaller motors with higher KV
One thing to bear in mind is to also make sure that your motors/ESC and other electronics are able to support the voltage of your battery. Some motors will only support a specific cell count Lipo, or a specific range of voltages which might make the decision easier.
In general most people in the community have settled on 4S as a sweet spot for ~250 as a nice middle ground for weight, power and also useful for 12V step down.
In all honesty its pretty simple, match you battery connector with you quad. In general be careful when soldering a connect at the battery end due. And STAY AWAY FROM BULLETS!!!
Below are the three most common types. At Drone Insider we tend to stick to the XT series for their quality, ease of use and availability
- xT30 for the 120-150 Class
- xt60 for the 180-250 Class
- xt90 for 300+
Hopefully this guide gave a rough outline for what is a good battery choice for your multirotor. With average use most batteries wont last more than a year especially if you push them hard. If you want to know what the best batteries and brands we like and use at Drone Insider go to our Top 5 Lipos to see.
Article Source: http://droneinsider.org/explained-whats-best-lipo-miniquad/