Is it Time to Replace your Batteries? Here is how you can find out!

[@cupko44]

I was looking for some kind of DIY backup system for my daughter's medical equipment in case of a longer interruption of the city power supply. The devices have their own internal battery, which is enough for an hour of autonomy. After your first video, the search ended :) I ordered the same batteries from GWL, assembled everything and did a couple of tests and the devices worked for 18 hours on backup. The first real test was the earthquake on March 22, 2020 in Zagreb, the power outage at home lasted for 5 hours. After that I ordered 4 more batteries, Victron MultiPlus and solar panels. After that, there were several interruptions in the electricity supply due to network works until the 6.1 earthquake on 12/29/2020 in Bania. Another test in disaster conditions passed. The investment paid off, and we see that the future brings all kinds of challenges. GreatScott, THANKS for the super educational videos!

[@PyroRob69]

Buy a real UPS. Or buy two of them.

[@r2db]

@@PyroRob69 You have not used a well-built Victron system if you are making this comment. A UPS is not designed to supply current for extended periods of time. Even my larger rackmount UPS units will never keep going for 18 hours. Most UPS systems sold to home users and small businesses still use lead-acid batteries, which are not designed for repeated true deep cycling (even the "marine" or "deep cycle" batteries are not designed for cycling as deeply as more modern battery chemistries). An off-grid system is designed for long-term continuous use, and lithium iron phosphate cells are designed for repeated deep cycling that far exceeds these deep cycle/ marine lead acid batteries.

[@PyroRob69]

@@r2db I never said anything about using lead acid batteries, and none of my UPS's have lead acid batteries in them. Go build a battery room then. /shrugs.

[@r2db]

@@PyroRob69 You have only addressed one of the issues, battery chemistry, but provided no details for your supposedly superior solution. The models equivalent to the lead-acid units I have are roughly double the cost with about the same runtime, which is probably why the lead-acid units still rule in the home/ SMB market here. Again you demonstrate your lack of knowledge regarding a reasonable system for this person's problem. UPS units, even those designed for enterprise use, measure their runtime in minutes, not hours. My server rack UPS will not last 8 hours. At about 20% load with batteries that are still serviceable my units can't quite hit 2 hours. They are designed to provide power long enough to get your generator online, not long enough to restore utility power in case of a prolonged outage. One does not need a "room" for a reasonable off-grid system for life support equipment.

[@PyroRob69]

@@r2db As I said, go build yourself a battery room. Those are not to hold everything, they are to hold everything while your generator starts. Thought you might know more about this based on your original comment and the medical necessity.

[@davidefogagnolo]

I based my master thesis on active BMS capable on performing Electrochimical Impedance Spectroscopy (EIS). You basically inject a sinusoidal current on the cell, measure the voltage perturbation on it and get magnitude and phase of the resulting impedance at that frequency. Usually, you only characterize the capacitive region which goes from about 1Hz to 1kHz, in the transition between capacitive and inductive behaviour you get the value of the AC cell (bulk) resistance

[@greatscottlab]

Thanks for the feedback. Interesting.

[@phoohb]

What is "Electrochimical Impedance Spectroscopy" (EIS)? (sounds like "Smith chart" usually for RF -stuff) Question, does the "internal resistant" shange with different frequency and magnitude ?? (and why not plot it from small-small frequency, say nanoHz???)

[@davidefogagnolo]

@@phoohb it's the name of the technique I mentioned before. The results are plotted on a nyquist plot, typically with inverted Y axis. There is no benefit in going lower than the mHz range, you basically measure DC resistance and it takes forever to get a measurement

[@yeahnah6468]

But did you fit it in such a way that ensures side fumbling is effectively prevented?

[@victoroliveroing]

David, are you working the same topic im odh studies?

[@duanejohnston8982]

Great as always! I love these battery/ off grid videos. Keep up the good work.

[@deadbird99]

Same here!

[@greatscottlab]

Thanks👍 There is more to come when the house is done✌️

[@Transtrash]

@@greatscottlab yes I love the these kinds of videos!!

[@speedsterh]

Interesting how your videos address practical problems (like this one, on aging of batteries) or more theoretical/"research" topics (wireless energy transfer for instance). All of your productions are excellent either way, I always learn a lot with them. Thank you very much for what you do !

[@Bobesz9]

Dear Scott, I work with Winston cells for years now and do a lot of measuring for customer requests. Discharging with 0.1C is not that accurate if you want to find out the health of your cells. The optimal discharge current presents a much close number for the real capacity. Love your videos, keep up the good work!

[@hammadiazaiez9337]

do you mean that testing a 3 amp hours battery at 3 amp discharge is optimal?

[@Bobesz9]

@@hammadiazaiez9337 3A for a 3Ah battery is 1C. The optimal discharge is in the cell specification. It depends on what it was intended for.

[@greatscottlab]

Sure but my normal load is 8 to 10A. That is for what I want to know the capacity.

[@serversurfer6169]

@@greatscottlab But unless you tested it with ~9A draw when it was new, you have no baseline to compare it against. So maybe now it pulls its rated capacity, but it might've done 110% when new with such a light load. Most capacity testing is done at 0.2C, for consistency.

[@Bobesz9]

@@greatscottlab Yeah, in your case it is totally fine.

[@Kyuunex]

I keep seeing people make this mistake, and I don't know why. I highly recommend not using an AC inverter whenever possible, not only due to some energy loss during convertion, but also because LEDs typically have terrible power factor. There are 12V LEDs out there, mainly meant for RVs, they can run both on 12V DC and 12V AC, and in case of DC, 4 of them (rated for 3-4 W) in *parallel* barely drawn an amp while giving off a very good amount of light, enough to normally light a somewhat large room. Same for laptop chargers, there are 12V chargers for laptops (meant to be used in a car), and they are efficient.

[@greatscottlab]

My LEDs run of the 12V of the battery. Only for the laptop example I used the inverter.

[@Kyuunex]

@@greatscottlab oh, okay. good. I assumed you used an inverter because they draw 8A. that is a lot.

[@akhurash]

@@Kyuunex Yeah this seemed excessively high to me as well, especially for LED’s.

[@pistol0grip0pump]

0:01 - "Bomb has been planted " springs to mind! lmao seriously though this is kick ass! Well done!

[@STNG17-]

FYI, if you compare iR for different battery cell, you will get different R value (can be by a lot) depending on what kind of cell. You cannot simply said one cell is "healthy" just by its iR. Ex: For high A output cell, the iR will be much lower that the high capacity one.

[@KastaRules]

Man, almost every time I watch one of your videos I end up getting myself a new toy. Or two. You are bankrupting me.

[@greatscottlab]

Sorry about that......but it is for a good cause ;-)

[@PeterMilanovski]

Off grid garage has been using this battery tester for some time now, he's a mad German living in sunny hot Queensland Australia, and no! You can't have him back, he's ours and we are keeping him 🤣...

[@matteol.7311]

I loved when you couldn't accept such a big difference in the results and then went on looking for the cause of it. Real engineer spirit

[@MicSokol]

I have an industrial 220Ah lead acid battery hooked up to a Tripp lite inverter/charger for over 14 years, it still works, all I do is top distilled water every couple of months. It powers all of my electronics at home.

[@julioda5914]

This is a very important video because it show us that a project needs to be tracked and upgraded in the time

[@vlademalis7306]

Ah, your video came in just in time, as I am assembling a "portable" 8s powerbank with the same batteries. It is assuring to see the batteries still perform well, even with occasional misuse. Thank you for all the work you do!

[@bro_leo]

11:05 Maybe I am get married already when you go back to this experiment.

[@fathirendrawan5846]

Some notes about your video: There's actually some non-linear relation between capacity and current called Peukert's law. Basically the law state that the more current you charge to or discharge from the battery, the less your actual batteries capacity is. That's why in some datasheet, the capacity data is tested on some standardized parameter (current, temperature, etc).

[@hammadiazaiez9337]

for me just the DC - AC internal resistance test part still not clear. you said both of them are important but the difference in values were huge. and not close to manufacture values for the DC test but after that you said that they still are in good condition. so is that a NO for the manual dc method used in this video? i love your videos and im always learning from you GREAT Scott ❤️

[@spiderchopproductions8172]

Good video. Nice to see that in sub-optimal conditions the battery is still performing better than spec after 3 years!

[@greatscottlab]

Totally agree!

[@koushiks_energy]

Ending is epic 😂

[@JanTuts]

What will you do with your original LiFeYPo4 batteries during the 3 year experiment with the new LiFePo4's? Sell, just keep in storage, use in some other projects, ...?

[@NekitGeek]

Capacity meter - DIY or BUY?

[@greatscottlab]

I can put it on my to do list :-)

[@calyodelphi124]

Your commitment to this experiment and reporting back to us on its results is commendable and very useful for those of us who might someday be interested in assembling such a system of our own! :D

[@Agentti_Kowalski]

Now i know why the channel has great in it. Very informative and simple to understand.👍🏼

[@greatscottlab]

Thanks :-)

[@hummmingbear]

Can you do a video showing why it's not recommended to run AC wires next to DC wires? They apparently induce a DC voltage onto the AC side. I don't have the hardware/equipment to measure this but I would love to see a video on it. Thanks!

[@Simon-lj8bb]

Hey what about a Geiger counter DIY or BUY episode? You could even explore a DIY geiger tube!

[@HuangLuxuan]

in ideal internal resistance test, a small ac current in sine form should be apply to the cell and then measure the ac component of the voltage to calculate the complex impedance Z to the frequency f. but it seems that no one done it like this.

[@4ndY252]

that green simson at 0:12 looks clean af

[@suilqknadrotu934]

SR 50 on the right 😀

[@greatscottlab]

Thanks ;-)

[@TecSanento]

Dear lord it’s been 3 year since this Video ? Time flies for shure !

[@steffenbuettner4294]

1 kHz internal resistance measurement is somehow a standard, even though the conclusions drawn from it may be questionable, as you explained... I think conceptually it's somehow derived from the electrical impedance spectroscopy, but would be interesting to learn more about that!

[@MartinBalle7]

That is one hell of a cliff hanger, 3 years

[@calyodelphi124]

Long-term battery testing takes time. :3

[@xani666]

Having some smart heating circuit that just heats it when there are low temperatures + some good isolation could help

[@JagaimoNeko]

What did you do with the previous battery? Since it’s condition is still pretty good and you still have free room in the box, you can have them both set, not just one. In theory, you’d be able to run electrical instruments (saws, drills, etc.) with it.

[@miore580]

Thumbs up for the two GDR mopeds. I still ride my father's Simson Star.

[@RomanoPRODUCTION]

01:32 incredible smile 🖖

[@MiguelDeMarchena]

I use a lot of recycled 18650 batteries extracted from old laptops, this information you share on this video is very useful, thank you a lot

[@CL-yp1bs]

Awesome Scott! I own a ZKE Tech EBD-A20H - It has banana jacks unlike yours but it does not charge like yours does.. i love them!!

[@greatscottlab]

Thanks for the info!

[@CL-yp1bs]

@@greatscottlab Yep and if you ever have any problems with it disconnecting in the middle of a test where it stops collecting data switch to a different usb or “COM” port (like com6 instead of com1) mine was giving me issues at first because my laptop is going to sleep so I turned off auto sleep and then it was also disconnecting even not going to sleep, the machine would continue testing but the data would stop transmitting to my computer. but I am using a different USB port now under recommendation from someone else and I’m successfully doing several hour long tests with no issues… It looks like you were doing that anyways but just in case you ever have that issue this is something to make a note of.

[@rinokentie8653]

Interesting - as always! I have now used a LiFePo4 battery in my motorbike for 5 years without any issue.

[@greatscottlab]

Thanks for the feedback :-)

[@electroquests]

Hang on, you're not connected to the power grid? Man, that's awesome! It has always been my dream to stay off the power grid.

[@edwardvanhazendonk]

Nice result, those GWL's rock!

[@spicymemeboi2646]

Can we just take some time to appreciate all the beautifully clean drawings he makes for every video..

[@deslomeslager]

A new laptop used less power. Mine uses 12 Watt on average use and 30 something when stressed. It is not a gamer laptop. And how do you manage to draw 8A on your lighting ? ? ? If you want to be off grid, be sure to get the right appliances for it.

[@eDoc2020]

The stated power draw probably includes battery charging.

[@libervolucion]

Thank you, Scott, this was very interesting. Well, last time we had to wait a little bit for the drone, now we'll be looking forward to seeing what happens with this battery.

[@greatscottlab]

Thanks. We will see how it will work out ;-)

[@RealJohnnyDingo]

The west mountain radio CBA-V battery analyzer will do up to 150W discharge max, with maximums of 57V and 40A. the documentation and software are good too. I do like the display on this Chinese unit and I think it will charge (only to 18V) as well... Ebike batteries are usually 48 to 52V so the CBA-V would be a better choice in that instance. great video as always.

[@umountable]

Spoken like a true SUV driver: "What matters the most is the security of the people behind the stearing wheel" xD I hope that was not intended ^^

[@dh2032]

GreatScott!, question using your laptop on a main power plug? when off grid, this is the Question: would you not be better to use 12/24, car/van/lorry, power adapter, it power will be a lot closer to the laptop charging requirements, and the second part of the question: in the long run world save power, in the main wall power adapter still more efficient in power usage?

[@mm-hl7gh]

keysight is only sponsoring the most excelent channels! great work.

[@mgut17]

since this is a long term testing, check the AH and then check again after 3 years when the test is done

[@AndriusKamarauskas]

what do you think about an electrical blanket for your battery for those cold nights?

[@gregormackenzie80]

Isn't that PSU lead a standard C5 cloverleaf plug? First thing I did when moving from the UK to DE was get a load of DE power cables my laptop, monitor, printer etc (and make up a 4-way extension block with a German plug on it)

[@sneezee3785]

gotta love the tattu lipo

[@jedics1]

These LPA batteries have been around for so long now it amazes me they aren't the standard for everything everywhere, they are incredible value now with a proven track record. I have been using mine as my only power source for over 2 years now and since then cheaper more energy dense options are available even though it is the same chemistry. Apart from solar panels lpa batteries are the only good news in the energy sector for years and not being held to ransom by energy elites is makes building make real sense, being able to give power companies the middle finger feels really good...

[@surenbono6063]

...you can only expect

[@kjajmol]

In topic of storing energy from solar panels, would you make video about storing energy in form of hydrogen and oxygen and turnig it into electricity in fuel cells? It interested me very much and i would like to get to know more about it because I saw only a few videos about it.

[@tedhancock68]

Very practical video. Well done. Stay creative and see you...in 3 years.

[@jeffsadowski]

Awesome tutorial on testing your batteries.

[@EasyOne]

Great video, Scott

[@scottxiong5844]

Looking forward to data on the new battery!

[@greatscottlab]

Me too ;-)

[@eugenew2]

This whole solar project process should be its own playlist series.

[@novids4938]

Very interesting to see how well those cells hold up over time. I noticed you performed the DC resistance measurement on the steel bolt, which is a relatively poor conductor. That may have influenced the measurement significantly. So maybe it is not all that bad.

[@isiTsotsi]

If you look at the cost for the system you see being off grid with a small system only really makes sense if you don't have access to a reliable power grid. The 100kwh you used over the 3 years would have cost you only 35€, and that even with germany's extremely high electricity costs.

[@troublehd7236]

Perfect timing, I'm on the same problem right now

[@avejst]

great walkthrough of the problems with a rechargeable battery. Thanks for sharing your experience with all of us 👍🙂

[@joshualuciani3896]

With my Tiktok fyp showing more gardening videos and my youtube showing off grid solutions, I think I might be at the beginning of a lifestyle change lol

[@SeraphX2]

You never said if the 12 for the DC resistance was bad or not?

[@paskokelava2795]

Excelent video I am sorry if it didnt get as many views as some other projects, but that doesnt diminish its value

[@tirthvora5061]

Can we use wheastone bridge for measuring internal resistance. It's simple and accurate

[@neobreaker91]

I must know, what type or style of pens do you use? They always seem to write so clearly.

[@SuperBrainAK]

I remember that video! The LFP market has certainly exploded since then and the price certainly has gone down. Did you see if Lithium Solar has reviewed that Ampere Time battery yet? Good luck! Hopefully the solar garage will last another 3 years! I did notice you has some LED sections burnt out. Will you fo a video of you repairing the light?

[@jimbert50]

Why did you measure 2 voltages under 2 different resistive loads instead of just subtracting one voltage under a known resistive load from the open circuit voltage, then calculating the internal resistance from that?

[@greatscottlab]

Because the drop between open voltage and one load is pretty big and not representative for the internal resistance. That is why I used one small and one big load. Minimizes the error.

[@YourJapans]

Hi, I'm always fascinated with electronics yet I know nothing about it. So what should I read to understand what you were saying?

[@SpacyNG]

Nice follow up. Seeing the Victron MPPT again, I'm wondering whether you have tinkered with that BT module or if you're just using the factory app on the phone as shown in the video. I tried building a bridge with an ESP32 using BLE to connect to the victron to then send the data off to a MQTT/Influx/Homeassistant server. Sadly I discovered that Victron is not willing to open up the full BLE protocol. I have a BT wireshark file lying around from when the app connects and gets data, but didn't get to analyze it further yet. There have been community efforts to reverse engineer the protocol in the Victron forum, which interestingly Victron doesn't mind :D But that is still far from working. Viele Grüße aus Berlin.

[@ZaiFuchigami]

An easy way to do that is to use Victron open source VenusOS firmware and run it on a Raspberry Pi. You can get a VeDirect to USB cable from Victron that allows you to hook up the charge controller or any VEDirect device up to it. From there you can integrate 3rd party automation/monitoring systems. I have a Raspberry Pi 3 running in my DIY Powerwall setup monitoring two Victron charge controllers, a Victron Multiplus and a Victron Battery Monitor. Works great and allows for remote monitoring via the internet.

[@SpacyNG]

@@ZaiFuchigami Yeah I saw, that serial communication protocol is open source, so that's probably the way to go. That's why I don't understand, why Victron doesn't open up its BLE protocol. I'll probably do serial in the future, but with a custom coded ESP-based firmware. I think for the VeDirect there even is already an ESP implementation. But thanks for the suggestion. If you already have an RPi in your setup that's probably the easiest and best way to go.

[@separatedig9567]

5:46 Free 46mah. Yay!

[@packratswhatif.3990]

Scott, for the fun of it, if you powered the laptop directly off the batteries (assuming 13 volts would drive it) how much longer could the laptop run. I think I would like a 24-48 volt system if I could afford it and then I could have any voltage below that to run stuff from without having to go thru the power inverter.

[@perito_valligiano]

Great! Are you planning to do a video on MPPT controller?

[@JustPyroYT]

Good Video as always 👍👍 0:33 That path of the Arrow.. 😂

[@greatscottlab]

Take my predictions with a grain of salt though ;-)

[@spagamoto]

As another option, many RC chargers have a discharge/capacity check function, like the imax b6. Some even let you automatically run multiple charge/discharge cycles and also give you a rudimentary measure of ESR. Enough to get a rough idea.

[@drkastenbrot]

The imax B6 is utter outdated garbage (especially the clones), i'd recommend isdt for better low budget option.

[@spagamoto]

@@drkastenbrot sure. Mine continues to give me good service almost a decade later, but yeah, avoid the clones.

[@drkastenbrot]

@@spagamoto The problem is the firmware, even the original one. They didnt properly handle fault conditions, so while it works absolutely fine with batteries that are in good shape, it gets really unpredictable with faulty or worn batteries. Ive had it try to charge lipo cells to 6V and completely fail to balance. Other chargers would stop charging with an error message but the B6 just doesnt.

[@AtlantisArch]

ok, but what are the measure you got from the new battery pack ? You can't compare if you didn't do the initial measurement.

[@allthegearnoidea6752]

I’m not a fan of these battery systems for the same reason I don’t store petrol at home. Although if it’s something you have to do the fair enough. Another great video thanks for sharing! Best regards chris

[@Nitecrow314]

LiFePo cells aren't a fire risk.

[@allthegearnoidea6752]

@@Nitecrow314 Of course they are a fire risk the short circuit current for such batteries is in the hundreds if not thousands of amps. Do you seriously want that amount of energy storage capacity in domestic situation. There are literally hundreds of fires caused by battery storage and UPS installations every year.

[@suji730]

Great great video Hard work behind the scenes I love it Getting allround result

[@millomaker]

Very interesting video :)

[@valentin333]

Cred că în realitate mai importantă este măsurarea rezistenței in DC deoarece aceasta ne spune ceva despre pierderile de putere pe care le avem atunci cînd consumăm curent din baterii,cît și despre cît s-ar putea încălzii bateriile.

[@Lucavon]

2:15 I think there's a third, very important property: Whether it is currently on fire.

[@JohnDuthie]

Can you build an AC resistance tester using an Arduino?

[@ArthursHD]

Could make a heating/cooling system for the battery. Most lithium batteries are designed to be charged above 0°C and can even be dangerous after being charged at low temperatures due to the formation of dendrites.

[@Subgunman]

Very informative video! Is that cabinet made by Hager?

[@tellmey1]

cant wait for the follow up video in 3 years

[@samda7109]

wieder ein gutes Video. mich würde ein Video interessieren wie ein Wechselrichter funktioniert und sich falls nötig zur Einspeisung einer Akku-USV zurück ins Hausnetz eignet bzw. warum er sich nicht so einfach eignet (Stichwort Phasenangleichung)

[@RussellTeapot]

There is something I don't quite understand about how the information regarding the cutoff voltage is presented in batteries datasheet. If I understood correctly, simply put the cutoff voltage is the point at which the battery is considered 100% discharged. When reading several lead acid batteries datasheets, I found out that often in the datasheet there is a table that lists the discharge times for a given constant discharge current and a given cutoff voltage. For instance, taking values from a real datasheet, let's assume that I have a 12V 22Ah lead acid battery. For 10h of discharge time, with 10.8V as cutoff voltage, the discharge current is 1.99A, giving a total capacity of 19.9Ah, which is a little bit less than the nominal capacity, but is to be expected: the "effective" capacity somewhat depends on the current draw, so no surprises here. However, if I take 9.6V as cutoff voltage, the discharge current given is 2.05A, with a total capacity of 20.5Ah. Usually is not recommended to discharge a lead acid battery more than 50%, so the "available" capacity would be 9.95Ah (10.8V cutoff) or 10.25Ah (9.6V cutoff). Now let's say that I have a 2A constant current load, which can function even at 9V (I'm pulling this out of my ass). Since the current draw is close to discharge current given above, that would give me around 298 mins of service time (if I consider the total capacity at 10.8V cutoff) or about 307 mins (if I consider the total capacity at 9.6V cutoff). In both cases it's about 5 hours of service time and 50% DOD, so what value should I consider for cutoff?

[@johnaoanan5429]

Hi sir Pls make a fish shocker ung mosfet

[@jrapplefan2231]

New ideas for your next videos: 1) Using 2 ADC converters like ADS1115 to make a 32 bits precise conversion. 2) Using a Teensy 4.1 or else to output a precise 4-20 mA. (Or a few 4-20 mA on the same microcontroler). Thank you for your work.

[@christossymA3A2]

Your video is awesome as usual , but i would really like to find out more for the camera transmitter of analog video you posted in your IG

[@greatscottlab]

I will get to it soon ;-)

[@ronelomagtang1340]

hi, thanks for the video.. i learned a lot.. may i ask how can you see the details of the battery in the cellphone?

[@kairasa3536]

Really well done!

[@Davidslabofficial]

Great video Scott! I need to test My batteries now 😃 Thank you so much!

[@iKn-ft2bc]

GreatScott! Would it be possible to get an App overview like at 3:59 for a battery thats inside your phone? So that your phone can monitor your phones Battery data?

[@macjonte]

So you can quickly measure battery status by its internal resistance by measuring current and voltage during use? Why isn’t all stuff doing this measurement instead of just voltage?

[@0401asdf]

Ich liebe deine Videos über Akkus

[@anonuser2640]

This is a very informative video and so much useful

[@greatscottlab]

Glad it was helpful!

[@HairyNumbNuts]

Cool. Someone else in the world got an Australian plug! We spend our lives getting European and American ones.

[@fanfan-tz2tk]

Very interesting one ! Thanks for sharing