After researching online I have shortlisted the best Lipo Internal Resistance Meter, which you can select items for checking drone battery right now. That’s because greatest tool is precision for pilot.
How to calculate lipo internal resistance without meter?
The following formula is well known for calculating internal resistance.
R= U/A
In order to more accurate, you should get the voltages at different current loads at less 2 times. Then use above formula to calculate the effective IR.
Take an example,
If you give the lipo battery pack 11v at 5A then goes down to 10V at 10A, you can get the IR is
11V-10V / 10A-5A = 1/5 =0.2 ohms
You will find that different voltages at different current have different internal resistance, therefore, you can work out the IR in voltage must under a particular current load.
In fact,it’s rather complex in its implementation, because there many facts impact the result, such as your applying (little current load or heavy loads), temperature, flight time etc.
Therefore, What’s the prefect way to measure lipo internal resistance?
In my experience, the most accurate way is using the meters (In the following part) to measure the IR. This is the purpose of this article to help you to examine battery IR as precisely as possible.
Best lipo internal resistance meter
All of the IR meters are cheaper on the market, therefore there are very popular and parctical tools for drone battery. There are 3 type meters of lipo internal resistance, each of them is unique.
And I make sure is that these lipo internal resistance meters are good enough to make it to below recommendations.
Stand alone lipo internal resistance meter

First, we are talking about stand alone battery IR meter: TOMTOP Smart Digital Battery Capacity Checker. As the name implies, this battery meter not only check battery IR, but also have many features as below list:
- Battery balancer
- Battery discharger
- Battery capacity checker
- ESC / Servo PPM tester
- Battery internal resistance tester
5 in 1 battery internal resistance meter

The next up is another meter: 5 in 1 internal resistance meter.
What’s 5 in 1? Due to it has 5 main functions: capacity checker, battery balancer, battery discharger, battery internal resistance tester, and ESC/Servo PPM tester.
As you see, this meter is helpful for you to check and maintain your battery. Also supply a reliable PPM signal to test and adjust your servo motors.
Chargers with IR meter features

The last in our list is Chargers with IR features built in.
It’s a super charger, Automatic Charging Current Limit, Capacity Limit, Temperature Threshold and Processing Time Limit which makes the charger safe to use. Can charge two different kinds of batteries simultaneously.
Besides that, users could also use it as c and Lipo Internal Resistance Meter.