Lithium Battery Capacity Testing (Intermediate Level): Shunts, Hall Effect Sensors and more! 

Does off-grid solar confuse you? Check out my DIY friendly website for solar system packages and product recommendations, and so much more! www.mobile-solarpower.com Join our DIY solar community! #1 largest solar forum on the internet for beginners and professionals alike: www.diysolarforum.com Check out my best-selling, beginner-friendly 12V off-grid solar book (affiliate link): amzn.to/2Aj4dX4 If DIY is not for you, but you love solar and need an offgrid system, check out Tesla Solar. Low prices and great warranty, and they can take your entire house offgrid with their new Powerwalls: ts.la/william57509 ~~~~~~~~~~~~~~~~~~~~~~~~~ My solar equipment recommendations (Constantly updated! Check here first): 12V/48V Lithium Batteries: www.mobile-solarpower.com/solar-batteries.html Solar System Component Directory: www.mobile-solarpower.com/solarcomponents.html Plug-N-Play Systems: www.mobile-solarpower.com/full-size-systems.html Complete 48V System Kits: www.mobile-solarpower.com/complete-48v-solar-kits.html DIY Friendly Air Conditioner/ Heat Pumps: www.mobile-solarpower.com/solar-friendly-air-conditioners.html Complete 48V System Blueprint: www.mobile-solarpower.com/48v-complete-system-blueprint.html ~~~~~~~~~~~~~~~~~~~~~~~~~~ My Favorite Online Stores for DIY Solar and Coupon Codes: -Current Connected: SOK, Victron and High Quality Components. Best prices and warranty around: currentconnected.com/?ref=wp -Signature Solar: Cheap Server Rack Batteries and Large Solar Panels: www.signaturesolar.com/?ref=h-cvbzfahsek -Ecoflow Delta Official Site: My favorite plug-n-play solar generator: us.ecoflow.com/?aff=7 -AmpereTime: Cheapest 12V batteries around: amperetime.com/products/ampere-time-12v-100ah-lithium-lifepo4-battery?ref=h-cvbzfahsek -Rich Solar: Mega site and cheaper prices than renogy! Check them out: richsolar.com/?ref=h-cvbzfahsek -Shop Solar Kits: Huge site with every solar kit you can imagine! Check it out: shopsolarkits.com/?ref=will-p -Battery Hookup: Cheap cell deals bit.ly/2mIxSqt 10% off code: diysolar -Watts 24/7: Best deals on all-in-one solar power systems, with customer support and distribution here in the USA: watts247.com/?wpam_id=3 ~~~~~~~~~~~~~~~~~~~~~~~~~~~ Contact Information: I am NOT available for personal solar system consult! If you wish to contact me, this is my direct email: williamprowsediysolar@gmail.com Join the forum at diysolarforum.com/ if you wish to hang out with myself and others and talk about solar FTC Disclosure Statement and Disclaimers: Every video includes some form of paid promotion or sponsorship. Some links on this youtube channel may be affiliate links. We may get paid if you buy something or take an action after clicking one of these. My videos are for educational purposes only. Information is subject to change/update at any time. Electricity is DANGEROUS and can kill. Be smart and use common sense :) DIY Solar Power with Will Prowse is a participant in the Amazon Services LLC Associates Program, An affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com

I love your enthusiasm and blunt honesty in all of your videos, especially about your disappointment in the products you demonstrate and test for our edification, but what you yourself would recommend that the manufacturer should do to rectify the situation - on top of changing their damn advertising to reflect THE truth about the reality of the product they are pushing. Good god. My house is in escrow now and I am soooo close to buying my RV and outfitting it with all Victron and Battleborn components - YES! Keep the vid's coming my friend, you ROCK...

Keep doing a great job with your videos! It's nice to see someone actually taking the time to test all those products our there. About the 120Ah cells doing only 116, it's actually close enough that the 4Ah gap can be covered if you take the wires losses into account (try to calculate their resistance and the I2R losses at 1C test) and also the accuracy of the shunt/hall device circuit. Usually it's 1-3% of full scale, meaning you can get couple of Ah difference. One other thing is that those low-voltage cutoffs are according to what the load device measures, but due to the high currents you can get large voltage drops on the wiring between cell and load device, resulting in cutoff when the cell voltage is actually still higher, meaning again - more capacity is there. Try measuring the cell voltage right on the terminals with a DVM when the cutoff kicks in. Enjoy!

I found a great way of putting my wife to sleep and getting her of my back for a while, haha.I just put on one of your videos. Dont get me wrong I love your videos, she's not so keen, to all the blokes out there, you should try it.

13:51 "can only handle 60 or 80 amps...." It's not that they list the "wrong" information. What they are listing is the "surge" rating of absolute max of the components. So if a FET is rated to handle 20A continuous, but 60A surge for 2s, then they'll list 60a on the page. It's not "wrong", but it is misleading as they don't also say "surge" rated. For anything to handle loads, take the rating that they list, then derate by 50% - 60% for continuous output.

Will, I'm a welder, I bought an inverter welder that advertised 315 amps from ebay, when plugged into 380 vac. I don't have 380 vac but it works on 240 vac, when I plugged it in and turned it All the way up while welding the max I could get in amps was 127 amps while the digital display showed 315 amps !!!, I measured with a Fluke #36 clampmeter, it showed 127 amps !!!. this is also from China, everytime I bought something that sounded like it was pushing the limits of truth, it was B/S, it's a Big liers game, GREAT VIDEO Thanks William Orange county, ca.

If AliExpress trustworthiness is 50/50, then it's a coin toss. I still like the Hall effect units. THANKS again for testing these critters!

Great stuff, thanks Will. Was just getting up to the point of wanting to capacity test my project battery and intended to do some research into hall effect sensors. Now I don't need to! Thank you

Great video for an old guy trying to learn this solar set up stuff. Got your paperback book a while back . Completely finished it once and use to spot check stuff now. digital download information is very helpful & convienent!! Thank you for all you do. Miss your videos on S. Cal RVing thought.

Sam thanks for all your video.. you do a lot of the home work on products that a lot of us do not have the time to do. We enjoy making our own stuff and want tge best product fir the job at a reasonable price..

This is exactly what I have been looking for. I ordered three of them.

Bought one today with a large colour screen and android Bluetooth support. Love it :)

Just to let you know, the false advertising in asia is very comment, I live in asia country, when I need something like 100A I would need to get a 200-300A rated products.

The simple shunts are accurate because they are tested & trimmed. You'll probably see a little notch cut into the edge of the metal. E.g. by laser. The depth of the notch sets the resistance.

For lower C rate tests, I prefer to use an RC charge with regenerative discharge. I pump the energy back into a larger battery bank and can use the energy to charge the cells/battery back up. I like the iCharger x6/x8 which can do 6S/8S at 30A. good small flexible solution for testing.

I use the BOGART ENGINEERING SHUNTS 500A/50MV. I will up 300 amps on it with out much heat, and seems well made

I love using those testers...I have the one with the huge square fan, 180watt.....but I upgraded the fet to an IRF1404. Works even better now!!! The only thing or difference between using this and my Reaktor 300w 30ampvRegenerative discharge. When the battery gets to eoc, the Reaktor will reduce the amperage by 5-25% till it hits 0amps. These dischargers just give the amps or watts balls to the wall, till you stop it or have it set to. Reaktor can have this turn off also. I just hear other people claim I lose the actual capacity this way(I do not agree), I tried to explain in real-world use, we would use the batteries balls to the wall and we wouldn't manually reduce the amps as a basic discharger does. I think discharging like this gives you the most accurate capacities. Great Video Will as always!!! Also there is a setting on those dischargers that shows the resistance also!!!

I got one of these capacity testers about 2 weeks ago (the one with the round fan). it is good quality and i'm very happy with the tester. My 3 used Valence U1-12RT (each 40 Ah) pulled in parallel 125 Ah. I also tested a regular old car battery (70 Ah) with it and it only scored 65 Ah. So now i know that i will replace the old car battery in my camping van with the three Valence U1-12RT batteries.

It's quite possible that it can only do 100A if running at 5V or something. What is the max "Wattage" output? The size of the shunts can handle 100A easy. The problem is the circuitry handling the voltage AND the current at the same time. I've seen tests where they did something like 20V and pulled low amps. But dropped to 10V or so and the max amps was doubled easy.

Does anyone else ever feel like the dumbest person in the room after watching some of Will's videos? :)

10:47 - The screen shows that you were only pulling 1073.19 watts. Divide by 12.5V = 85.85 amps. So it was working fine any why it never went over 86 amps. You weren't pulling enough watts to get to 100 amps. Have you tested this one any further?

Your detailed videos are showing how much research you carry out before presenting, find it refreshing. Recently I was watching a video where the load was an invertor and I thought that is the way to discharge a battery or individual cells. The only problem I thought of was no cut off voltage relay. Do you have any suggestions or ideas for this approach? I also searched around for an invertor that would allow a range of input voltages as in 3vdc to 60vdc. Don't know if this type of device exists. Thank you for any help you can send my way.

If you raise that fan and heater tester up a few inches and blow a small desk top fan on it, you can set the max watts to 260 watts. That's 20 amps at 13 volts. I do it routinely.

Your videos are 1000% awesome

I have not been able to set the low voltage disconnect on those fan machines. Have you tried changing it? It's stuck at 0v for me.

You do very well very good and I like the way you are honest

It’s great you do these tests . Love your videos

a little cheat commonly used by ebike DIYers and the shunts in the BLDC motor controllers...a little solder on the shunt to get the amps up. Wouldnt take much to get 15 amps more. Assuming the datasheet on the MOSfets and capacitors indicate they truly are good to go.

I like those little testers with the purple fan. Think I've got 5 maybe 6. Took the makerhawk folks 4 months to send me new mosfets, now 2 outa 5 or 6 work lol. They're cheap, but if you get one that works keep it below 170 watts n turn the knows down when not in use n it'll last you a while

Hey Will, I bought a supposedly 315 amp dc inverter welder, on 240 vac, but with my Fluke Clampmeter it only maxes out at 127 amps even though the digital display says 315 amps, plus this is dead shorting the leads to get maximum surge !!!, over half of what I buy from China as far as electronic things go are phony specs. And over rated just to sell their products !!! Watch Out !!! I really love how you teach, I learn a lot from you, keep it going 😃😃😃

I am new to battery capacity testers and my question was since I did not hear it on here: do you need to have the battery fully charged to do a capacity test or you can have it at any capacity to start the test?

Hey Will. As you mentioned about the max current of the BMS ... maybe you can make a video about how good the high current BMS are. I have seen the Daly 200A BMS with only 16mm2/6AWG witch is crazy.

Wil it's time to start making them here in the state's people will pay knowing they can trust you and not wanting to keep sending stuff back to China is really where the value is, time is money and we all value our time more than money its one thing you can't buy. Thanks for your dedication to your craft buddy. keep the videos coming.

I use my DC Series Motor as the load on the battery. I have a large shunt and programmable digital DC power watt meter JLD404. I use a contactor to switch the high current loads using the meters built in switches. It is a bulk setup but you can do a low volt cut off and it will count for you. My DC motor will pull upwards to 60 amps with no load on the motor except the weight of the armature itself. Works great. So the 60 to 80 amp device would work great with my DC motor load.

Will, I found this question below about a battery I just purchased on Amazon. I'm wondering about the -20 degrees cut out as compared to your comment of -7 degrees cut out? Q: Does the bms have overcurrent protection? does it turn the batteries off at 10v? low temp, high temp? A: yeah, of course,BMS have the overcurrent over-voltage protection function.its cut off voltage is 10v, low temperature is -20degrees. high temperature is 65 degrees

I have bought one of those low C rate capacity tester last year and realize that all my LiPO4 batteries were not giving the capacity I was supposed to get. I did not know we could set the low voltage shut-off on those small units. I think it is the battery PMS that shut the battery down and end the test. Anyway they are good small tester. Like you say I did double check the amperage with an good fluke amp meter. And the amps where the same as the capacity tester so I think the amp hour and kWh should be accurate as well.

I know this video is a year old but I'd love to see Will review a Kunkin KP184 which can be a 400 watt load tester as well as serve a ton of other useful electronic functions. Maybe even a video where Will goes over all the features as they most apply to DIY solar and Lithium battery systems.

Do you need a consistent load when using a hall effect? Just wondering if i can do a load test while say running my desktop on an inverter and get an accurate test?

Great video could you not use a DC heater as a tester .

At 11:00 current is controlled by load NOT by tester. Your load is 1000 Watts so 85A is correct! To get to 100A at 12V you need a >1200 Watt load. Put a 2000 watt load on the inverter and I guarantee you will get over 100A! Also at 11:49 -- Shunt size is dictated by voltage sensing of shunt measurement. A full scale sensitivity of 50mV will dissipate 5 watts at 100A. this will get quite hot however if sensitivity is 10mV then only 1W is dissipated in shunt at 100A and that shunt will handle it easily.

Will, take a look at the battery analyzer from West Mountain Radio. I think it would be a great tool in your box. You can also use it to watch the performance of your solar panels during the day. It is a great tool. It's also reasonably priced.

It doesn't really matter if they are accurate, as long as they are inaccurate the same every time! Especially if you are cell matching! I guess consistent is what I mean, concistancy over accuracy!

Will, will you please try an iCharger? I use an X8 and it is great as it can charge and discharge up to 30amps, and it can regenerate the discharge power into another battery.

Hi. Thank you so much for your videos and could you please make a video on cooling of solar panels ( elaborated). I didn't find any useful video

Hi, thanks for this. With an inverter load it will have high peak currents as the sine wave goes over the crest. This is not the same as a purely resistive load and may explain the 84 amp limiting.

My used Valence 138Ah batteries are arriving soon, the Chinese load testers will arrive late August to mid-September. So I found some 200W and 400W enclosed boxes in Rowland Heights, CA for $92 and $217 respectively. Any interest in reviewing something available in days rather than weeks? These also look less unfinished than the open circuit board design. THANKS!!!

Check the specs... I bet it's limited to Max 300v, Max 100A, Max 1000 watts... 84 amps at 12v is about 1000 watts

Always superb. Thank you!

7:49 a 4S LiFePO4 pack LVCO is 11.5VDC? why not 2.6x4 or 10.4VDC? Need to know, about to test a 12VDC 8Ah LiFePO4 pack with one of these in two days :)

I wanted to check the SOH of the leaf cells. or the capacity check of individual cells. what should be the stop voltage i should set. because i can not let the battery drain to zero. and please explain cell capacity in Amp hours, and watt hours. which one is more accurate. thanks for your well detailed videos.

After watching your video following the link to purchase a 180-watt unit but it was nowhere to be found. Did they stop building these?

Thanks for sharing videos with us. Where can I get a high c rating capacity tester. I’m trying to test over a hundred headway HP cells, so the faster the better. Any recommendations?

I also use these dummy loads to measure capacity, current, voltage. Their accuracy is mostly o.k. but you can also find low accuracy ones. They tend to build these things cheaper and cheaper not taking care of quality components and construction. It mostly depends on the accuracy of the shunt. For example current readings accuracy can change over the whole range, the same for voltage and this makes them less reliable. But still overall accuracy is o.k. for private use, but error maybe around 1% and sometimes more of reading.

How do you use the rheostat as a tester? Did you ever get another one. Is it as simple as using it as the load?

What are the proper voltages for LiFePo4 capacity testing - upper charge limit and low battery cut-off? I understand that low cut-off in normal operation should be somewhere around 11.4v - 12v ... but what is a number for actual capacity testing?

i have the same capacity tester but with bigger cooler and it works perfectly

Is the term "ripoff" being used too harshly? While I understand that there is a ~3% variation on the advertised 120AH compared to the actual 116AH. The thought of getting the batteries for much cheaper than a better brand seems worth a ~3% loss. Can this variation still be a long-life battery or is it a symptom of a product that will have a reduced life span? Btw, thanks for the videos, I've been watching a lot of them, and feel like possibly I'm learning something.

What if the LifePo4 battery has a BMS with bluetooth? Would the bluetooth be accurate enough if you hooked the battery to a load in order to find out the Ah's of the battery?

Will for these kind of tests you need to be using at least one calibrated standard test equipment. Keep up the good work!

Please test the iCharger X8. The regenerative capability is far more energy efficient than just wastefully dissipating the cells energy away.

It appears to be rated for 100 amps at the maximum voltage of 300v. Maybe they should list the voltage derating curve in the advertising or on the spec sheet. Their ad actually makes sense in a Chinese kind of way, they show a picture of it not quite showing 100a at not quite 300v.

Thanks for the video. I would really like something a bit more sustainable and self-contained… and mains powered. What I had in mind was something like the Revolectrix cellpro powerlab 8 that permits regenerative discharge into a large battery so that you can use the energy again to charge up your cells under test rather than just waste the energy as heat. Obviously if you’re dealing with large format cells with possibly Multiple hundreds of Ah , just throwing the energy away is rather wasteful. If you have any ideas, please reply to this comment.

Do you know if there's a way to log the data via one of the USB or other ports? It'd be interesting to set it up and then show the voltage sag over time.

Yes I do agree 100%

Prob with their design is that when the low level reached it just keeps disconnecting reconnecting the load it does not end the test permanently

Did you post the link for the hall effect?

Quick question for you Will. I recently purchased some "grade A" 105ah cells from Ishann. (yes I knew going in that I might not get full capacity based on your comments). I did exactly this and tested the capacity only to discover 85ah instead of the promised 105ah. The seller is telling me "They are very favorable, please cycle a few more times, the battery capacity will increase." This is just a line of BS isn't it?

I think you should add a warning to put a min voltage cutout for all battery types. Just tested a 6v lead acid cell to 100% depletion, and now it won't charge back.

Hey Will. What charger/power supply do you use for charging/initial balancing of cells? Can't seem to find that info anywhere...

awesome educational video like always, thanks

I would like a tester for checking 20v and 60v tool batteries, I noticed my 8 ah rated batteries don't last that much longer than a 5 ah, both purchased in 2023 (only a couple months old) I get 20volt tool batteries that get weak and I have to pull them apart to find that one of the cells is lower voltage I would like a faster way to determine battery pack health. Any suggestions?

I have installed a lithium 24 volt system to power a Victron 3000 watt multi plus with charger. My batteries are 4 /100 A/H lithium . People are telling me not to hook them up as 2P 2S configuration . That 12 volt lithium's are only good in 2P . What do I need to do so that I can use them in a 24 volt system ?

Would one of the “cheap” ones work for a 48v 200ah build?

Plz explain complete wiring of battery monitor with shunt and test of internal resistance of a battery. Thanks.

Why does the my 45 amp Progressive Dynamics AGM charger require 3440 WH, as measured with a KilaWatt, to charge a 200 AH, 12 Volt, Ampere Time, LiFePo4 battery that only returns 2565 WH when connected to a 20 amp load and discharged to 10 volts? Is it inefficiencies in the charger, wrong testing setup, or inefficiencies in the battery? Should I be measuring the charging energy with a shunt?

Hello Im testing 48v batteries for my e bikes. Where did you get your xt60 cable to connect to the battery tester?

VERY IMPRESIV. SMART MAN, THANKS.

Most of my equipment is for testing 18650 cells, I can fairly easily test 8ah 10ah cells, recently I had a heck of a time testing some Nissan leaf cells! My testers kept timing out after 18-20 hours haha, I guess I need to regroup or invest,

another good way you could drain a large battery without making a lot of noise is to boil a huge pot of water on an induction cooktop Edit:ice water is preferred obviously

another viewer made the comment that at 84amps you are pushing about 1000 watts.. Just wondering what is the capacity of your load inverter? If it is a 1000 watt inverter you may not have sufficient load.

Old video but Awesome

85A vs spec 100A, could it be because the load (heat gun) didn't draw that much current?

But how do you charge a single Lithium iron phosphate battery just the benchtop power supply or do you have a specific charger for that? because you should charge the cell before you test it, don't you?

You didn't say if the 85? Allegedly hundred amp tester would disconnect when low threshold voltage was reached. If so, this would mean some kind of transistor switch that can handle 85 amps and the high voltage. . I saw this for like $12. How can I do it?

Why did you move away from the hall effect tester that you showed at the begining ? Thanks

Do the other models WITHOUT the fan (i.e. the 85 amp one, the other 85 amp one with the black shell, and the hall effects one) that can test at a higher C rating also have a user defined automatic low voltage disconnect? I prefer a model that can discharge at a higher C rate but want one with an automatic low voltage disconnect too. Thank you.

Ave just made a video about using electrolysis as a cheap and easy load for testing a generators output, can this be used for this type of testing as well?

Hello .. does the big one wich has a fan , suitable for test capacity of 18650 ?

Do you think these woud be good for folks in cold climates to keep batteries from freezing?

How many watts was the heat gun pulling? Was it enough that it would be 100 amps?

For higher currents, parallel 2 of the sensors and add the results together.

I have a Outback 48 volt solar system with a FP1 power panel. I am looking at Lifepo4 batterys and wonder if you can install capacity tester inline?

Hi will, can you take a look at EBC-B20H? There is a possibility to conetct this tester with pc and draw a discharge diagram.

Do any of these devices compensate for the change in resistance of the shunt as they heat up ? The change can be significant if they get as hot as you say.

When you get a chance do a review on a graphene battery, thank you.

I bought the $46 test from your link on Amazon! I have multiple batteries I've built I want to verify my capacity math on! (I usually just run a certain load using an amp meter and calculate the time based on the amperage to get my calculations) but I wanted to verify with this tool and this is just what I needed! A question I have is what charger do you use to charge just a single 3.2V LifePO4 pack??? You are awesome and I love watching all your videos! I have learned more from watching your videos than I could have ever learned from reading from whatever I found on Google!! Keep up the amazing work and I'm glad you're living your dream making tons of money from your affiliates and doing what you love!!! You are an inspiration to what I do for a living too (I also love my job).

Will, I am building a 4v 6kWh 3.7V LG Chem powerwall. Which method would you recommend?

Is there an inexpensive turnkey current sensor with inline relay for cutting power at a particular voltage or current?

Can you do a solar hot water tank from a mobile home

Just bought one of these from Amazon and it appears that the min voltage is no longer adjustable. The two knobs only adjust the load. Seen a few other comments with people having similar problems. Very difficult to test these then without a BMS. @willprowse