I don't think it makes any sense for the reading to latch as it will not show a dropping voltage on the cell you are testing. If the voltage drops under the load of the tester, you won't see that happening.
It's thinking like that which leads to locks that are easily bypassed and hackers breaking into computers, because it's the "things that make no sense" that tell you the most about how something works, and how to get it to behave in ways the creator never anticipated.
That latching is terrible. Same battery will display a range of voltages when inserted in and out because the first reading latches in and never self-corrects.
But it's a battery tester. It is not meant to be, and does not pretend to be, anything else. It works as a battery tester and, therefore, does what it says on the tin.
Hi Julian, do they have a built in load for testing the cell? Some testers read a higher voltage when reading and there is no load across the testing cell/battery .
The moving coil meter BT168 has a network of resistors to load down the cell. The digital battery testers pull just enough current to run the controller and display.
Then the moving coil meter with the load is a TRUE battery tester then. I wish they would tell that in the description of it. This makes it more desirable. Thanks for the information.
@@davidwalters8225 Yeah - the BT168 also gives a pass/fail indication for non technical users. I've bought BT168's for the family and don't get calls about battery operated electronics that aren't working properly anymore.
Excellent review! Many don't understand latching to the first reading instead of sampling, and how absurd it is! It also makes this tester inaccurate. Same battery shows different voltage every time. The display will not self-correct because it latches onto the first reading - however random & inaccurate it may be. STAY AWAY FROM THIS THING!
That's why I trust my trusty $20 3-1/2 digit Mastercraft multimeter which actually has a "Battery" test setting. This draws a small current from the battery to give a true reading. PS - I enjoy your videos, Julian. Cheers from Canada :-)
It seems like the tester would not show you if the voltage drops under the load of the tester. It would take one reading and hold it. Meanwhile, your cell voltage is actually dropping rapidly just from the tester load.
My sliding model has a gotcha. If you try to measure a 9V battery with the slider closed, it will read 1.5-2.0v low because of the connection. Slider must be open!
The latching is not necessary at all. What is the purpose ?? My device gets a different reading every time when connecting with the SAME battery ! Probably it latches too quickly during the measurement. Sorry, but it is completely useless, even as a tester. Do not buy this.
It doesn’t seem to be much good as a battery tester either, BT189 reads 0.9v and 3:19 BT168 reads 0.8v that is a difference of over 10%. Loving the shed set up.
There must be a better way to monitor the voltages. Using something that you have no control over is just plain madness. the next one you buy might do something completely different. Stick to a true volt meter and there should be no issues when buying the next one.
Yeah, I don't get it... Voltage monitoring devices exist, why take apart a battery tester? You could even wire up one of those cheap multimeters that always seem to be given away for free with a purchase, or sold for pound with a coupon if very low power consumption with an LCD screen was the main objective...
there are load of self powered lcd panel meters out there, but i will give it to you that they are not as cheap as your battery testers. but I expect a lot more accurate. @@JulianIlett
Din păcate nici unul din acele "instrumente" nu merita atenția unui electronist cu minime cunostinte, Pentru ca nu indica curentul si puterea absorbita de sarcina ca sa stii limitele capacitatii bateriei testate
You could probably build something with an Arduino or two and several lcd screens that would do this job (and potentially a lot more (Data logging maybe ?))
@@JulianIlettIs your use case for 24/7 LCD screen monitoring, or just for datalogging? Because if you can find something that has a very low current sleep mode you could just have it wake up every minute, log a reading, then go back to sleep, making it less of a deal if it uses milliamps to take the reading as it won't be spending very long in that operating mode. But of course you don't get the LCD display in that case, you have to use some other device like a phone to view the logged voltage graphs.
I have to assume this is a synchronous buck converter. I'm pulling about 20 amps from the output and it runs stone cold. Not cheap (around $40 all in) but well worth it.
Definitely sounds promising. I'm going to be using it along with some other stuff to try to get the highest efficiency out of my server rack. Pretty much converting everything to 12V DC instead of 120V AC, then running it all from a single high efficiency 12V source. This buck regulator will be on the backup batteries, and a server power supply (you can get used platinum efficiency 1KW+ server power supplies for like 20$ delivered) for normal 120v operation. Mostly trying to get rid of the iron core UPS backup inverter from the equation. It's hugely inefficient at keeping my stuff online during a power outage.
A battery tester contains a volt meter, how else would it display the voltage? But is your car really made out of 2 scooters and your pc out of a toaster? Or why would you expect to find them inside?
![Lp. Сердце Вселенной #60 РОЖДЕНИЕ ЛОЛОЛОШКИ [Финал] • Майнкрафт](http://i.ytimg.com/vi/YoR0pAV9FVQ/mqdefault.jpg)
The latching display makes perfect sense. What makes no sense is trying to connect two batteries at the same time.
I don't think it makes any sense for the reading to latch as it will not show a dropping voltage on the cell you are testing. If the voltage drops under the load of the tester, you won't see that happening.
It's thinking like that which leads to locks that are easily bypassed and hackers breaking into computers, because it's the "things that make no sense" that tell you the most about how something works, and how to get it to behave in ways the creator never anticipated.
That latching is terrible. Same battery will display a range of voltages when inserted in and out because the first reading latches in and never self-corrects.
But it's a battery tester. It is not meant to be, and does not pretend to be, anything else. It works as a battery tester and, therefore, does what it says on the tin.
Cheap voltage meter.
It's terribly inaccurate because of the latching function. Same battery will display a range of voltages when inserted in and out.
Even as a battery tester i'd want to see if the voltage was going down, even of it only updated once a second or something.
Correct. With the latching there is no update at all!
Does it put a load on the battery under test? If so, how much?
Hi Julian, do they have a built in load for testing the cell? Some testers read a higher voltage when reading and there is no load across the testing cell/battery .
That could explain why it holds the reading, so as not to flatten the battery by having the load connected continuously
There is no built-in load on digital display meters.
The moving coil meter BT168 has a network of resistors to load down the cell. The digital battery testers pull just enough current to run the controller and display.
Then the moving coil meter with the load is a TRUE battery tester then. I wish they would tell that in the description of it. This makes it more desirable. Thanks for the information.
@@davidwalters8225 Yeah - the BT168 also gives a pass/fail indication for non technical users. I've bought BT168's for the family and don't get calls about battery operated electronics that aren't working properly anymore.
It's not even good as a battery tester. I bought one and had to return it. It gave a wrong reading because it puts no load across the battery.
And even if it would put a load, because it holds the first reading, you wouldn't read the real battery voltage.
How do you test button batteries with it
I have a 9 volt battery which reads at 7.43. what does that mean? It looks to me that it still has some charge in it. 😮😮
what a nice set up in your shed Julian
Excellent review! Many don't understand latching to the first reading instead of sampling, and how absurd it is! It also makes this tester inaccurate. Same battery shows different voltage every time. The display will not self-correct because it latches onto the first reading - however random & inaccurate it may be. STAY AWAY FROM THIS THING!
So who the hell is going to put 2 batteries at the same time and complain but yoy? lol
That's why I trust my trusty $20 3-1/2 digit Mastercraft multimeter which actually has a "Battery" test setting. This draws a small current from the battery to give a true reading. PS - I enjoy your videos, Julian. Cheers from Canada :-)
i have one of these and so far its not been an issue, for a quick check of my NiMH batterys its doing just fine
batteries is the plural
It seems like the tester would not show you if the voltage drops under the load of the tester. It would take one reading and hold it. Meanwhile, your cell voltage is actually dropping rapidly just from the tester load.
My sliding model has a gotcha. If you try to measure a 9V battery with the slider closed, it will read 1.5-2.0v low because of the connection. Slider must be open!
Nice reason to get a complete refund. just take a photo aof an aa battery with 6V and get your money back as it is clearly malfunctioning.
The latching is not necessary at all. What is the purpose ??
My device gets a different reading every time when connecting with the SAME battery !
Probably it latches too quickly during the measurement.
Sorry, but it is completely useless, even as a tester. Do not buy this.
EXACTLY! Normal meters sample readings, usually 3x/sec. This thing latches onto whatever was the first reading.
That's actually a pretty good idea using those battery testers to monitor voltage of the battery cells! Do you have a video of you doing that?
Thanks :) Yeah, search my videos for BT168
It doesn’t seem to be much good as a battery tester either, BT189 reads 0.9v and 3:19 BT168 reads 0.8v that is a difference of over 10%. Loving the shed set up.
There must be a better way to monitor the voltages. Using something that you have no control over is just plain madness. the next one you buy might do something completely different. Stick to a true volt meter and there should be no issues when buying the next one.
It's difficult to find a self-powered, LCD voltmeter. The BT168 (D or PRO) works superbly.
Yeah, I don't get it... Voltage monitoring devices exist, why take apart a battery tester?
You could even wire up one of those cheap multimeters that always seem to be given away for free with a purchase, or sold for pound with a coupon if very low power consumption with an LCD screen was the main objective...
Unfortunately, multimeters are not self-powered.
there are load of self powered lcd panel meters out there, but i will give it to you that they are not as cheap as your battery testers. but I expect a lot more accurate. @@JulianIlett
this item arrived in my mailbox just today from aliexpress, what a coincidence
Din păcate nici unul din acele "instrumente" nu merita atenția unui electronist cu minime cunostinte,
Pentru ca nu indica curentul si puterea absorbita de sarcina ca sa stii limitele capacitatii bateriei testate
You could probably build something with an Arduino or two and several lcd screens that would do this job (and potentially a lot more (Data logging maybe ?))
That sounds like tens of milliamps. I need tens of microamps :)
Yeah, that's a lot harder to do. @@JulianIlett
@@JulianIlettIs your use case for 24/7 LCD screen monitoring, or just for datalogging? Because if you can find something that has a very low current sleep mode you could just have it wake up every minute, log a reading, then go back to sleep, making it less of a deal if it uses milliamps to take the reading as it won't be spending very long in that operating mode. But of course you don't get the LCD display in that case, you have to use some other device like a phone to view the logged voltage graphs.
I just wanted to have at-a-glance cell voltage monitoring. I don't need remote monitoring or logging.
That buck converter looks awfully similar to the one I *just* bought on aliexpress to convert my server rack to run off battery backed DC
The brand is RCNUN. I should have said the seller is RCNUN.
@@JulianIlett Yup, that's the same brand I got. The quoted efficiency spec is impressive.
I have to assume this is a synchronous buck converter. I'm pulling about 20 amps from the output and it runs stone cold. Not cheap (around $40 all in) but well worth it.
Definitely sounds promising. I'm going to be using it along with some other stuff to try to get the highest efficiency out of my server rack. Pretty much converting everything to 12V DC instead of 120V AC, then running it all from a single high efficiency 12V source. This buck regulator will be on the backup batteries, and a server power supply (you can get used platinum efficiency 1KW+ server power supplies for like 20$ delivered) for normal 120v operation.
Mostly trying to get rid of the iron core UPS backup inverter from the equation. It's hugely inefficient at keeping my stuff online during a power outage.
hmm why do you not just buy the simple Mini Digital LED Display 4 Bits 0-100V Voltmeter Panel Volt Voltage Meter
LED is too power hungry
woof, a panel meter would be too easy. I think I'd Bluetooth to a uC then rs232 to a usb serial adaptor to a PC, that should about cover it.
@@TheEmbeddedHobbyistMeow! yes something a bit more technical would be good a designed item maybe 🙂 of couse PCBway could supply the board
I'll add it to my ever growing list of projects. one current project is a very large pile of rust that was once a Disco2. 😞@@fredflintstone1
@@TheEmbeddedHobbyistinstead of bluetooth, why not go with an ESP32 over wifi, using esphome, straight into home assistant.
They are cute though
Damn cute!
Yes, my toaster is no good as a volt meter either.
But it a toaster IS good as a companion for a bathtub 😉
Clearly you're not trying hard enough
@@vink6163My inventiveness has gone to the dogs. I'm actually surprised I got any responses for that off the cuff comment.
Who what have thought that a battery tester is not a voltmeter! Next we will find that my car is not a scooter and my PC is not a toaster!
A battery tester contains a volt meter, how else would it display the voltage? But is your car really made out of 2 scooters and your pc out of a toaster? Or why would you expect to find them inside?
I once used the exhaust of my PC to warm up and keep warm a poptart
What was the voltage of the poptart?
Aneng garbage brand, got it.