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Testing Battery Cells and Internal Resistance with YR1030+ Internal Resistance Tester

As I was testing my solar garage application, but assuming that all cells would perform this way, I started thinking if there's another way to skip the long capacity measurement and still find out whether a battery cell is still usable. And of course, there is method 2, aka the internal resistance.

For that, let me introduce you to this YR1030+ Internal Resistance Tester that you can also get from the internet. As you might know, the internal resistance of a battery is crucial when it comes to powering loads. You pretty much always want it to be as small as possible because this way even when powering a big load which demands lots of current, the voltage drop across this internal resistance will be rather small and thus the output voltage stays stable and the battery does not heat up so much.

And since the internal resistance basically stands for the conditions of the materials and chemicals inside the battery, you know that a high value means that your battery has problems. So as an example, I used the resistance tester to measure the internal resistance of all the cells of my big battery pack and they were all pretty close to one another and almost all of them still lower than the value given by the manufacturer.

But just to make sure, I also did a manual resistance measurement by putting two different load resistors onto one cell while measuring the cell voltage. Since I knew the exact load resistor value, I was able to calculate the flowing current and also the internal resistance of the battery cell which is apparently suddenly way higher than the resistance I measured before.

Now granted my method is not super accurate since the battery discharges while supplying the load but this difference is just too big to make any sense. Well as it turns out, the resistance meter can only measure the AC internal resistance while my method measured the DC internal resistance which is the one I described at the beginning and thus is basically a bit more important.

The AC method does exist though because its measuring signal of 1KHz that gets applied to the battery and whose respond gets measured is pretty much standardized for manufacturers while there is still a lot of debate about how a standardized DC internal measurement should look like. But either way, both methods can be an indicator if your battery is still good.

I also want to present to you this Li-Ion battery pack from a friend of mine who used it in its boombox since 2015. As you can see, its measured resistance is above 1ohm and after ripping it open and getting access to the individual cells, we can still measure at least 250mohm for each while a healthy cell comes with a value 20 times lower.

And as expected, this battery pack can no longer store energy successfully and definitely needs to get replaced. With that being said, you should now have a good idea how to test your batteries properly which means I can recharge my big battery pack and get it ready for installation in the garage.

But while doing that, I started to wonder whether regular Lithium Iron Phosphate Batteries without the Y for Yttrium that makes it more cold temperature compatible, would have performed as good. Since you can get them for way cheaper and even as low as $400 for a 12V 100Ah premade battery pack which is quite a big price difference to my DIY battery.

So what can I say I got myself such a battery and installed it inside my garage to conduct a long term experiment which means I will see you all in around 3 years for the conclusion. With that being said, thanks for watching. Don't forget to like, share, subscribe and hit the notification bell. Stay creative and I will see you next time.

WEBVTTKind: captionsLanguage: enThis right here is my big Lithium Iron Phosphate battery pack that I have been  using for almost 3 years as the sole energy source in my off grid solar power garage. Back then I had no other choice than creating an off grid solar system because I was  and still am not hooked up to the power grid.But I think nowadays the topic of off grid power  is more important than ever with more and more extreme weather occurring  and of course rising energy prices.And while I previously showed you exactly  how I came up with, calculated and built an off grid system with decent energy storage;  you never got to see the aftermath and by that I am not talking about the solar panels, connectors,  controller and whatnot because all of those more or less still work perfectly fine. No; I am of course talking about the battery itself and how it is holding up after 3 years of  constant usage because honestly speaking I used it pretty recklessly during pretty low temperatures  and also drained it 5 times completely so that the undervoltage protection kicked in. So in this video I will not only put this big battery pack to the test  but also this rather small one for a Boombox in order to show you exactly how you can  test your Lithium Ion batteries and find out whether it is time to replace them. Let's get started!This video is sponsored by Keysight  and their new 90 minute bootcamp “Automotive Cybersecurity: Everything you need to know.”  Watch this free bootcamp to discover what kinds of threats automakers are up against,  why regulators and standards bodies are getting involved and how an automated  approach to Cybersecurity testing protects what matters most – the people behind the wheel” Now there are 2 properties of a battery that give away whether it is still usable  and that is its capacity and internal resistance. First off; the capacity is pretty self explanatory. For example one of my battery cells comes with a nominal voltage of 3.3V and a capacity of 100Ah. That means after charging it up with its advised charging voltage,  we got around 330Wh of energy stored inside it. And since I got 4 of them in series the voltage multiplies by 4, so around 13.2V,  with still a capacity of 100Ah which means we got a total energy capacity of 1320Wh. And I know that this energy and capacity value sounds super theoretical. So as a practical example we could take the lighting in my garage which draws around 8A  of current from the battery pack.100Ah divided by 8A would equal  a lighting run time of around 12.5 hours before the battery is empty. Or another example could be my laptop here which requires around 70W maximum. Meaning we can divide the 1320Wh of total energy by 70W in order to find out that the battery  can power my laptop for almost 19 hours if we ignore the power losses of the required inverter. I think you get the idea why this capacity value is super important  and sadly this value can decrease drastically overtime depending on whether you mistreated  the battery or reached its cycle life limit early.In my case though I only stored 108kWh of energy  inside the battery pack so far which would theoretically equal around 82 cycles. So that should not be the problem but like I said there were some low temperatures. Now to measure the remaining capacity and energy, we could create some kind of DIY circuit  that draws a constant current while measuring the voltage as well as keeping track of the  time because those are basically the 3 ingredients we need to calculate how much energy the battery  can hold and what is its remaining capacity.But since messing with such big battery pack  in the wrong way can be quite dangerous; I instead consulted the internet to find out  what everyone else uses in such a case.And as it turns out this EBC-A20 battery  tester seems to be mighty popular and needless to say I got myself one as well. And I have to say that I was rather impressed with its build quality;  but I was not so happy about the Chinese only manual and the plug adapter they wanted me to use. But luckily I can easily connect the correct plug and there is also an English manual with  software available on their website.So after installing that and having a  quick read through the manual, I realized that it is pretty self explanatory to use. After powering the tester and connecting it to a computer, all you have to do is hook up the  included wires, connect those to the battery terminals, set the current load and cut off  voltage values in the software and click start.And that is basically it and as you can see it  worked beautifully with my small LiPo battery here which comes with a measured capacity a  bit bigger than on its label, nice.By the way I also double checked  the measured voltage and current values and it all seems to be pretty accurate. So time to hook up one big battery cell, set its cut off voltage to 2.8V,  like the datasheet recommends it, and the current load to 10A which is a bit higher  than the 8A my lights require but due to time constraints I went with a bit of a higher value. And with that being said the test started and while that is going on let me tell you that  testing the battery pack as a whole with the 4 cells in series would have made more sense  but then the tester could have only drawn around 85W of power  and honestly speaking nobody got time for that.But anyway after around 10 and a half hours  the the measurement came to an end and revealed a remaining capacity  of 106Ah and an energy of 334Wh which is frankly speaking fantastic and way better than I imagined. That basically means that my battery pack was and still is well suited for my solar  garage application; but of course only if we assume that all cells would perform this way. So is there maybe another way to skip this long capacity measurement  and still find out whether a battery cell is still usable? And of course there is with method 2, aka the internal resistance. For that let me introduce you to this YR1030+ Internal Resistance Tester  that you can also get from the internet.As you might know the internal resistance  of a battery is crucial when it comes to powering loads. You pretty much always want it to be as small as possible because this way even when powering a big  load which demands lots of current the voltage drop across this internal resistance will be  rather small and thus the output voltage stays stable and the battery does not heat up so much. And since the internal resistance basically stands for the conditions of the materials  and chemicals inside the battery, you know that a high value means that your battery has problems.So as an example I used the resistance tester to measure the internal resistance of all the cells  of my big battery pack and they were all pretty close to one another and almost all of them still  lower than the value given by the manufacturer.But just to make sure I also did a manual  resistance measurement by putting two different load resistors onto one cell  while measuring the cell voltage.Since I knew the exact load resistor value  I was able to calculate the flowing current and also the internal resistance of the battery cell  which is apparently suddenly way higher than the resistance I measured before. Now granted my method is not super accurate since the battery discharges while supplying the load  but this difference is just too big to make any sense. Well as it turns out the resistance meter can only measure the AC internal resistance while  my method measured the DC internal resistance which is the one I described at the beginning  and thus is basically a bit more important.The AC method does exist though because its  measuring signal of 1KHz that gets applied to the battery and whose respond gets measured is pretty  much standardized for manufacturers while there is still a lot of debate about how a standardized  DC internal measurement should look like.And the AC resistance will also always be lower  because it includes the capacitive properties of the battery. But either way both methods can be an indicator if your battery is still good to  and to prove that I present to you this Li-Ion battery pack from a friend of mine  who used it in its boombox since 2015.As you can see its measured resistance  is above 1ohm and after ripping it open and getting access to the individual cells we can  still measure at least 250mohm for each while a healthy cell comes with a value 20 times lower. And as expected this battery pack can no longer store energy successfully  and definitely needs to get replaced.With that being said you should now have  a good idea how to test your batteries properly which means I can recharge my big battery pack  and get it ready for installation in the garage.But while doing that I started to wonder whether  regular Lithium Iron Phosphate Batteries without the Y for Yttrium that makes it  more cold temperature compatible, would have performed as good. Since you can get them for way cheaper and even as low as 400$ for a 12V 100Ah premade battery pack  which is quite a big price difference to my DIY battery. So what can I say I got myself such a battery and installed it inside my garage to conduct  a long term experiment which means I will see you all in around 3 years for the conclusion. With that being said thanks for watching.Don't forget to like, share,  subscribe and hit the notification bell.Stay creative and I will see you next time.