How to Choose A Proper Battery
01-23-2016, 01:58 AM
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How to Choose A Proper Battery
Choosing the correct Lipo RC battery for your model involves many factors, and you must first have an idea of the voltage and amp requirements of the motor/prop combination that you intend to use. This article guides you through the thought processes involved in choosing one or more batteries for your RC models. There are a number of factors to consider when it comes to choosing a battery pack. Before making a purchase, think about these points:* Voltage
* Capacity
* Weight
* Physical Size
* Connector
* Discharge
* Charging RateBattery Voltage (S)All Lithium Polymer cells have a nominal voltage of 3.7v per cell. When fully charged a LiPo cell should be 4.2v and when discharged it should never be below 3v. You will notice that LiPo packs are made up of layers of multiple cells. A 1S = 1 cell (3.7v). If the LiPo pack is listed as being 3S this means it is 3 cells x 3.7v (per cell) which is 11.1v (3s 11.1v lipo battery). It has 3 layers of 3.7v each. The rating for each cell is always referenced by its nominal voltage (3.7v), NOT the maximum voltage (4.2v).
Capacity (mAh)This is usually the biggest or most obvious rating shown on the LiPo pack and is measured in mAh (Milliamp/hour) or Ah(Amp/hour). The capacity is an important factor to consider. Think of capacity (mAh) as the amount of fuel in your car's fuel tank. A higher capacity tank will run your car for longer. 55 amps is the maximum safe current a motor can draw from this battery.The mah rating: 2200mAh is 2200 milliamp hours or 2.2 amp hours. That is the amout of energy the battery can hold. This battery will give 2.2 amps of current for one hour. Or 4.4 amps for 1/2 hour, or 8.8 amps for 15 minutes.WeightA 25c 2000mah Lipo battery can weigh from 170 grams to 270 grams depending on the brand and model number. When you look to buy a battery, weight should be one of the thins you look at. Some 1600mah batteries weigh as much as some 2200mah batteries. A batteris has a huge effect on the planes power to weight ratio. Two extra ounces will make a big difference in your planes performance. Jets need a better than 1 to 1 power to weight ratio to perform like a jet.Physical SizeFor a battery to be right for your model it must fit within the model’s battery compartment. Not all batteries are the same size. While most manufacturers try to stay consistent in sizing, the dimensions can still be quite a bit different. Sometimes a 2mm difference in size might keep it from fitting in your model.Battery ConnectorsSoldering battery connectors can be a real pain, so it is a good idea to try find a battery connector that you like, and stick to it. That allows you to swap batteries easily, and if you decide to build another drone in the future you can use the same batteries.
* Capacity
* Weight
* Physical Size
* Connector
* Discharge
* Charging RateBattery Voltage (S)All Lithium Polymer cells have a nominal voltage of 3.7v per cell. When fully charged a LiPo cell should be 4.2v and when discharged it should never be below 3v. You will notice that LiPo packs are made up of layers of multiple cells. A 1S = 1 cell (3.7v). If the LiPo pack is listed as being 3S this means it is 3 cells x 3.7v (per cell) which is 11.1v (3s 11.1v lipo battery). It has 3 layers of 3.7v each. The rating for each cell is always referenced by its nominal voltage (3.7v), NOT the maximum voltage (4.2v).
Capacity (mAh)This is usually the biggest or most obvious rating shown on the LiPo pack and is measured in mAh (Milliamp/hour) or Ah(Amp/hour). The capacity is an important factor to consider. Think of capacity (mAh) as the amount of fuel in your car's fuel tank. A higher capacity tank will run your car for longer. 55 amps is the maximum safe current a motor can draw from this battery.The mah rating: 2200mAh is 2200 milliamp hours or 2.2 amp hours. That is the amout of energy the battery can hold. This battery will give 2.2 amps of current for one hour. Or 4.4 amps for 1/2 hour, or 8.8 amps for 15 minutes.WeightA 25c 2000mah Lipo battery can weigh from 170 grams to 270 grams depending on the brand and model number. When you look to buy a battery, weight should be one of the thins you look at. Some 1600mah batteries weigh as much as some 2200mah batteries. A batteris has a huge effect on the planes power to weight ratio. Two extra ounces will make a big difference in your planes performance. Jets need a better than 1 to 1 power to weight ratio to perform like a jet.Physical SizeFor a battery to be right for your model it must fit within the model’s battery compartment. Not all batteries are the same size. While most manufacturers try to stay consistent in sizing, the dimensions can still be quite a bit different. Sometimes a 2mm difference in size might keep it from fitting in your model.Battery ConnectorsSoldering battery connectors can be a real pain, so it is a good idea to try find a battery connector that you like, and stick to it. That allows you to swap batteries easily, and if you decide to build another drone in the future you can use the same batteries.
01-23-2016, 03:02 AM
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Choosing the correct Lipo RC battery for your model involves many factors, and you must first have an idea of the voltage and amp requirements of the motor/prop combination that you intend to use. This article guides you through the thought processes involved in choosing one or more batteries for your RC models.
There are a number of factors to consider when it comes to choosing a battery pack. Before making a purchase, think about these points:
* Voltage
* Capacity
* Weight
* Physical Size
* Connector
* Discharge
* Charging Rate
Battery Voltage (S)
All Lithium Polymer cells have a nominal voltage of 3.7v per cell. When fully charged a LiPo cell should be 4.2v and when discharged it should never be below 3v. You will notice that LiPo packs are made up of layers of multiple cells. A 1S = 1 cell (3.7v). If the LiPo pack is listed as being 3S this means it is 3 cells x 3.7v (per cell) which is 11.1v (3s 11.1v lipo battery). It has 3 layers of 3.7v each. The rating for each cell is always referenced by its nominal voltage (3.7v), NOT the maximum voltage (4.2v).
Capacity (mAh)
This is usually the biggest or most obvious rating shown on the LiPo pack and is measured in mAh (Milliamp/hour) or Ah(Amp/hour). The capacity is an important factor to consider. Think of capacity (mAh) as the amount of fuel in your car's fuel tank. A higher capacity tank will run your car for longer. 55 amps is the maximum safe current a motor can draw from this battery.The mah rating: 2200mAh is 2200 milliamp hours or 2.2 amp hours. That is the amout of energy the battery can hold. This battery will give 2.2 amps of current for one hour. Or 4.4 amps for 1/2 hour, or 8.8 amps for 15 minutes.
Weight
A 25c 2000mah Lipo battery can weigh from 170 grams to 270 grams depending on the brand and model number. When you look to buy a battery, weight should be one of the thins you look at. Some 1600mah batteries weigh as much as some 2200mah batteries. A batteris has a huge effect on the planes power to weight ratio. Two extra ounces will make a big difference in your planes performance. Jets need a better than 1 to 1 power to weight ratio to perform like a jet.
Physical Size
For a battery to be right for your model it must fit within the model’s battery compartment. Not all batteries are the same size. While most manufacturers try to stay consistent in sizing, the dimensions can still be quite a bit different. Sometimes a 2mm difference in size might keep it from fitting in your model.
Battery Connectors
Soldering battery connectors can be a real pain, so it is a good idea to try find a battery connector that you like, and stick to it. That allows you to swap batteries easily, and if you decide to build another drone in the future you can use the same batteries.
There are a number of factors to consider when it comes to choosing a battery pack. Before making a purchase, think about these points:
* Voltage
* Capacity
* Weight
* Physical Size
* Connector
* Discharge
* Charging Rate
Battery Voltage (S)
All Lithium Polymer cells have a nominal voltage of 3.7v per cell. When fully charged a LiPo cell should be 4.2v and when discharged it should never be below 3v. You will notice that LiPo packs are made up of layers of multiple cells. A 1S = 1 cell (3.7v). If the LiPo pack is listed as being 3S this means it is 3 cells x 3.7v (per cell) which is 11.1v (3s 11.1v lipo battery). It has 3 layers of 3.7v each. The rating for each cell is always referenced by its nominal voltage (3.7v), NOT the maximum voltage (4.2v).
Capacity (mAh)
This is usually the biggest or most obvious rating shown on the LiPo pack and is measured in mAh (Milliamp/hour) or Ah(Amp/hour). The capacity is an important factor to consider. Think of capacity (mAh) as the amount of fuel in your car's fuel tank. A higher capacity tank will run your car for longer. 55 amps is the maximum safe current a motor can draw from this battery.The mah rating: 2200mAh is 2200 milliamp hours or 2.2 amp hours. That is the amout of energy the battery can hold. This battery will give 2.2 amps of current for one hour. Or 4.4 amps for 1/2 hour, or 8.8 amps for 15 minutes.
Weight
A 25c 2000mah Lipo battery can weigh from 170 grams to 270 grams depending on the brand and model number. When you look to buy a battery, weight should be one of the thins you look at. Some 1600mah batteries weigh as much as some 2200mah batteries. A batteris has a huge effect on the planes power to weight ratio. Two extra ounces will make a big difference in your planes performance. Jets need a better than 1 to 1 power to weight ratio to perform like a jet.
Physical Size
For a battery to be right for your model it must fit within the model’s battery compartment. Not all batteries are the same size. While most manufacturers try to stay consistent in sizing, the dimensions can still be quite a bit different. Sometimes a 2mm difference in size might keep it from fitting in your model.
Battery Connectors
Soldering battery connectors can be a real pain, so it is a good idea to try find a battery connector that you like, and stick to it. That allows you to swap batteries easily, and if you decide to build another drone in the future you can use the same batteries.
01-23-2016, 03:02 AM
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Another thing to consider is the C rating - this is the rate at which the battery can safely discharge. (In theory, some brands are better than others)
The amps for a specific C value will depend on the battery's Mah rating.
A discharge rate of 1C means it will discharge its full capacity in an hour.
Consider Battery A has 4000 mah capacity and Battery B has 2200 mah
Battery A discharging at 1C is providing a current of 4 amps.
Whereas Battery B discharging at 1C s providing a current of 2.2 amps.
If the batteries are discharging at 30C it means they will discharge fully in 2 minutes. (Not a good idea to fully discharge a Lipo though)
At 30C discharge
Battery A is providing 120 amps
Battery B is providing 66 amps
At 60C discharge - the batteries will be empty in 1 minute.
Battery A - 240 amps
Battery B - 132 amps
If your application requires more current than the battery is rated to provide then you may suffer voltage sag, battery puffing and overheating.
Therefore always use a battery with a C rating applicable to (higher than) the expected current requirement and plan to land with about 15-20% remaining in the battery.
Discharging too much or too fast will shorten the life of a LiPo and may lead to other problems.
The amps for a specific C value will depend on the battery's Mah rating.
A discharge rate of 1C means it will discharge its full capacity in an hour.
Consider Battery A has 4000 mah capacity and Battery B has 2200 mah
Battery A discharging at 1C is providing a current of 4 amps.
Whereas Battery B discharging at 1C s providing a current of 2.2 amps.
If the batteries are discharging at 30C it means they will discharge fully in 2 minutes. (Not a good idea to fully discharge a Lipo though)
At 30C discharge
Battery A is providing 120 amps
Battery B is providing 66 amps
At 60C discharge - the batteries will be empty in 1 minute.
Battery A - 240 amps
Battery B - 132 amps
If your application requires more current than the battery is rated to provide then you may suffer voltage sag, battery puffing and overheating.
Therefore always use a battery with a C rating applicable to (higher than) the expected current requirement and plan to land with about 15-20% remaining in the battery.
Discharging too much or too fast will shorten the life of a LiPo and may lead to other problems.
Last edited by Rob2160; 01-23-2016 at 04:22 AM.
02-16-2016, 11:57 PM
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Another thing to consider is the C rating - this is the rate at which the battery can safely discharge. (In theory, some brands are better than others)
The amps for a specific C value will depend on the battery's Mah rating.
A discharge rate of 1C means it will discharge its full capacity in an hour.
Consider Battery A has 4000 mah capacity and Battery B has 2200 mah
Battery A discharging at 1C is providing a current of 4 amps.
Whereas Battery B discharging at 1C s providing a current of 2.2 amps.
If the batteries are discharging at 30C it means they will discharge fully in 2 minutes. (Not a good idea to fully discharge a Lipo though)
At 30C discharge
Battery A is providing 120 amps
Battery B is providing 66 amps
At 60C discharge - the batteries will be empty in 1 minute.
Battery A - 240 amps
Battery B - 132 amps
If your application requires more current than the battery is rated to provide then you may suffer voltage sag, battery puffing and overheating.
Therefore always use a battery with a C rating applicable to (higher than) the expected current requirement and plan to land with about 15-20% remaining in the battery.
Discharging too much or too fast will shorten the life of a LiPo and may lead to other problems.
The amps for a specific C value will depend on the battery's Mah rating.
A discharge rate of 1C means it will discharge its full capacity in an hour.
Consider Battery A has 4000 mah capacity and Battery B has 2200 mah
Battery A discharging at 1C is providing a current of 4 amps.
Whereas Battery B discharging at 1C s providing a current of 2.2 amps.
If the batteries are discharging at 30C it means they will discharge fully in 2 minutes. (Not a good idea to fully discharge a Lipo though)
At 30C discharge
Battery A is providing 120 amps
Battery B is providing 66 amps
At 60C discharge - the batteries will be empty in 1 minute.
Battery A - 240 amps
Battery B - 132 amps
If your application requires more current than the battery is rated to provide then you may suffer voltage sag, battery puffing and overheating.
Therefore always use a battery with a C rating applicable to (higher than) the expected current requirement and plan to land with about 15-20% remaining in the battery.
Discharging too much or too fast will shorten the life of a LiPo and may lead to other problems.
02-17-2016, 10:23 AM
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Of course everyone knows that too much heat can degrade or destroy LI batteries. One thing I have always tried to do when selecting batteries for a particular application is to make sure that I will not discharge them at more than one half of their maximum discharge C rating. I have found that they stay much cooler and last a lot longer. I also never charge a battery at more than 1 C no matter what they say on them and this also extends the life of them. The trick is instead of fast charging them, just have more of them so you can always have some on charge while you fly.
I am looking forward to Sanyo's new chemistry that promises about double the charge density in a lighter pack than current batteries. This may be a couple of years off and I'm certain they will be pretty expensive at first but then I can recall back in 2003 paying $85.00 for a 2200 MAH Lipo that was only 20 C and thought that was good.
I am looking forward to Sanyo's new chemistry that promises about double the charge density in a lighter pack than current batteries. This may be a couple of years off and I'm certain they will be pretty expensive at first but then I can recall back in 2003 paying $85.00 for a 2200 MAH Lipo that was only 20 C and thought that was good.
