The lab

How strong is the temperature of your battery affecting the performance?

The test is intended to see how strong the performance of a battery is affected by the temperature.

The performance is measured by the dynamic race test while the tempering cabinet is preheating the batteries to different temperatures..

This is a closed test that will only be updated if there is a request.
Please do only preheat your batteries above 30°C if you know the heat development of your battery on your specific setup. Otherwise this will affect the lifetime of your battery. You should not exceed a battery (cell) temperature of 60°C. This test shall not only teach you more about our batteries, it will also show you why the temperature has the biggest influence on performance and IR (internal resistance) measurements.

IR information and performance tests are useless if there is no additional information about the temperature. The results will not be comparable. Please keep this always in mind if you see any IR information on battery specs.

So, let´s start with the basics. We take a look at the IR curve (internal resistance) and how it is related to the temperature. We can see a significant change of the IR while increasing or decreasing the temperature of the battery.

To measure the difference in performance we use the dynamic race test, a simulated race over 90s and 3 laps to compare the performance of the batteries under realistic conditions. The battery score is calculated from the performance while the race. The grey line in the background does show the different load levels during the race. The green line does show the voltage curve.

After explaining how the battery-score test is done, we will take a 1550mAh 4S battery and perform the test at different temperatures. The battery had the entire break in cycled done, was fully charged and tempered to 25°C. This will be the base of this test. Now let´s cool down the battery to 20°C and to 10°C and perform the test again. The results are really substantial and we can see how the score will decrease at lower temperatures. A reduction of just 5°C significantly reduces the performance of the battery. In case of a race event, the difference between two equal Pilots at the start and in the first laps can bring considerable advantages.

The reduction to 10°C is brutal, especially at the beginning of the test, the difference is simply serious. Only because of the heat development during the race test, the battery can find its way back to a quite normal performance at the end of the test.

And this is the reason why you really shoud warm up your batteries if you want to fly on cold days! You do not only lose performance, cou can also damage your battery if you race hard without pre heating!

If we can see such significant results by cooling the battery down, we should expect to get some good performance boosts if we heat up our battery. This is what we did in the next chart.

And here we are, heating up the battery from the base temperature of 25°C to 30°C and even up to 35°C. Will this give us a big performance boost? It does! Compare the Score values and the Voltage sag in the chart down below.

And now take the time and scroll up, back to the IR curve of the battery. The curve is going steep to the left from 25°C to 10°C, and becomes noticeably flatter from 35°C upwards. This is why the performance loss below 25°C is much bigger that the performance gain above 25°C And above 35°C the curve becomes so flat, that it is not worth pre heating above this temperature. And you can also damage your battery because it will also develop heat while flying and you should never exceed 60°C cell temperature.

If you do fly at a race event, keep your battery warm. Keep it a least in your pocket to keep a temperature of 25°C or more. It can give you an advantage over a pilot with similar skill and setup. So, why not use it?

The last graph will show all the performance graphs combined. Again, all graphs from 10°C up to 35°C will show you how strong the performance of a battery will change on different temperatures.

That’s why I’m doing such an effort, bringing the batteries to exactly the same temperature before performing any test. It is absolutely essential to create the same conditions for each battery, otherwise the results are worthless and not comparable. As already mentioned, the same applies to the internal resistance.

So if you see any information about the internal resistance or performance of a battery without an indication of the temperature the test was performed…
just point it out!

I hope these results did help you to understanding your batteries a bit more. And remember to be always a bit skeptical about battery tests and specs on any sites.

Thanks for reading

Ramon Hug
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    Welcome to
    Your independent source für racequad batterie tests.

Kindly Note

To be able to compare the different batteries for our Racequads within our group of pilots I was looking for a way to test them always under the same conditions without any human influence. And of course to be able to see how they change after usage.

But after i finished the test unit and did the first tests (always with new batteries), i decided to create a small website to share the information from this test unit with the community of racing pilots.

Maybe some of you do indeed find this data usefull. More batteries are on the way to be tested.

To understand the results, please do first take a look at the Test setup page.

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Docus (Ramon Hug)

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