More Details - BT168 and BT168D Battery Testers

More details on the BT168 and BT168D battery testers. Schematic and block diagrams. Tests on minimum and maximum operating voltages of the BT168D.

[@iblackfeathers]

you could probably use a power supply unit in dc and turn the dial to find the voltage ranges without having to rely on stacking different batteries together.

[@brucepickess8097]

Good point my thoughts entirely. 👍😏

[@brucepickess8097]

Don't know why they couldn't have included circuitry to apply a nominal load to give an indication of battery condition. As the open circuit voltage is no real indication.

[@mitsos306ify]

Thanks for your video! You are the first I've encountered who addresses the "measure under load" topic

[@dazle1]

So many commentors dont know what they are talking about. The 168D display puts a load on a battery so if the battery is bad it WILL show. A weak 1.3v battery by meter will drop below 1.0v with this tester. There is a video by a bloke on youtube that shows this in a breakdown of the unit. I suspected it when I kept getting drastically different readings on weak batteries from this tester and a meter, yet good batteries were very close. A meters display is run by an internal battery whereas this tester draws from the battery being tested to run the display, thus a small load. Which is all that is needed to show weak batteries.

[@adiands850]

so which is a better device for testing how full a battery is: the 168 or the 168D? thanks

[@why_do_you_want_to_know]

The "load" BT168D Pro puts on the battery is so small that it hardly matters to the reading. I have had almost dead batteries show as fresh on BT-168D Pro which would show as dead on analog meter.

[@dazle1]

If you have dead batteries showing voltage then you have a broken meter! To make an unsupported statement that the draw is negligible is like spitting into the wind. Not only did I clearly explain why there is a draw(no battery) , but gave not only my supporting evidence but also another youtubers evidence. A properly operating meter will definitely show a weak battery due to the draw, that a multimeter will show as still good.

[@thulinp]

I modded my BT-168D with a pushbutton to add a load resistor. Works well.

[@NaruuWak]

can you share what value you added for the load?

[@thulinp]

@@NaruuWak 18 ohm: bit of a compromise, it's a light load for an AA, heavy load for a 9V or CR2032. But it works well

[@jasonmonk7336]

9:33 for someone with so many bench power supplies floating around 😊😊😂

[@why_do_you_want_to_know]

I find that BT-168 (analog) is much more useful and accurate because it tests battery under load. Although BT-168 Pro has voltage table (good/bad) range printed on back side, the voltage it displays is not under real load, so it does not give accurate representation of battery condition. Only use I see for BT-168 Pro is for raw voltage checks in place of digital multimeter, not as battery go/no go tester.

[@andygozzo72]

the good/bad indications are very arbitrary as different devices will likely work down to different minimum voltage levels, 2 of my digital cameras need pretty much new batteries or they wont power up

[@blakey271able]

I don't know much about a lot but the battery tester not being used under load would this be the same as a multimeter then which is typically how I test my batteries or would the multimeter be better? Just curious it's not something I've considered but does make sense. Would testing the battery under load be more of a capacity type test? Sorry to bother you

[@why_do_you_want_to_know]

@@blakey271able Measuring small 1.5 volt or 9 volt battery voltage with a multimeter AND a 100 Ohm resistor across the battery terminals (both multimeter and resistor are across the battery terminals) gives a much, much better indication of battery health than just measuring voltage without the resistor.

[@fokcuk]

Any way to modify pro version to add an additional load to a battery?

[@why_do_you_want_to_know]

@@fokcuk Not that I know of, because if it was easy to do the manufacturer would have done it.

[@Ni5ei]

I have the 168Pro but find it quite useless since it doesn't put a load on the battery. I had a CR123 battery that measured over 3V but when I put it in my camera it wouldnt work at all.

[@stapallemachtig]

Mine gave me different readings each time I tried. Then there was a puff of smoke. Still looking for a good batt tester; I tried four thus far.

[@mharris5047]

I have been using a BT-168D (the digital version) for years. I actually had three of them but burned one out checking the voltage of the three AAA cell adapters in cheap LED mini-flashlights, it measured the first one accurately then never worked again. I just bought two of the BT-168 pro versions so I had something capable of checking the approximate voltage of an 18650 cell. Ironically, the two BT-168D has a slight variation on its readout with the same cell, the difference is about 0.09 volts (admittedly one has been in heavy use for about 7-8 years, the other almost unused as a spare). A quick comparison of the two BT-168 pro versions I bought recently show only a 0.02 volt difference using a three AAA cell flashlight adapter, they show 4.37 and 4.39 volts, respectively.

[@MarshaJ8800TU]

Having a bench power supply might make checking voltage ranges easier.

[@alankingvideo]

If you open the case and do a bit of butchery with a pair of snips you can make it so the red slide half comes out of the end of the case, you can then measure 18650s. I would also replace the cheap poorly soldered wire with a more flexible silicon coated wire. Edit: Mine reads 10% high so not much point.

[@mjrawesome3430]

I get conflicting information about those testers... Do they work correctly as battery testers or not? A lot of people claim that they are useless due to not loading the batteries enough, effectively making them volt meters... So are either the BT168 or the BT168D useful for testing AA batteries, or would I be better off with a multimeter and a resistor? If a multimeter + resistor combo is better, then how many ohms and should fixed or variable resistor be used?

[@fredflintstone1]

I have the 168 PRo, does go to 4.8V accurately, I did change the wire to the slide to a Silicone wire as the pvc wire kept breaking from the slide works great for a quick check 🙂

[@JulianIlett]

Does it max out at 4.8V? Cos the 168D tops out at 8V. Oddly, the analog 168 opens wide enough to take an 18650. But 4V across 3.9 ohms would mean 1amp so 4 Watts. I don't think that tiny resistor would be too happy.

[@restorer19]

​@@JulianIlett On my 168 Pro, the slider input (labeled "1.2V-4.8V") reads a 9V battery at 9.12V when the 9V input reads the same battery as 8.83V. The board is superficially similar to your 168D's, with some shifted component placement and tracks on the boost side, and more passive components (SMD resistor networks!) on the 9V/measurement side of the IC. The board is labeled "TLX-02", no mention of a 168 model anywhere, and dated earlier than your 168D board (2020-3-16 vs. 210310). The case is identical, except that the slider hooks onto the track with a riser in the center of the slider, instead of at the far end, letting it slide out just that bit further to fit an 18650. You could probably swap the slider from the analog version over to the 168D to let it measure 18650s. (And the table on the back of my case is typo-free :D )

[@RambozoClown]

But you didn't try hooking it up to the mains?

[@leonardob3254]

Thanks for the video! Do you think BT168D could check 1/2AA 3.6V batteries in its1.5V input?

[@dino6627]

I much prefer the analogue meter type, there is no good/bad indication on the digital and the accuracy of a digital display is somewhat irrelevant without a suitable load resistor, giving misleading results as shown. I wonder what voltage the chip is receiving by feeding 8V or more through the boost converter, could be over-volting it, or does it go through the 3V reg too?

[@blakey271able]

Do they have reverse polarity protection just curious and don't want to test it myself?

[@haryonods9552]

this BT can do discharge?

[@frankowalker4662]

I still have my analog battery checker from the 80's. It's the same principle but a different design.

[@andygozzo72]

is it a 'square' type with 'bent leg' arm? if so i have one

[@frankowalker4662]

@@andygozzo72 No, It's a long semi-circular tube with the meter at the top. You put the battery in the half tube and push up the base to get a reading.

[@andygozzo72]

@@frankowalker4662 ooer, havent seen one like that yet!

[@frankowalker4662]

@@andygozzo72 Yeah it's great. It goes from AAA to D size and has 2 prongs just below the meter for 9V batteries. The meter has red (bad), yellow (weak), green (good).

[@mharris5047]

@@frankowalker4662 Before these came out I used a cheap multimeter to measure battery voltages. In the old days of analog multimeters they worked but you were going on a wing and a prayer that it was still properly calibrated (I think I may still have a really old analog multimeter in the shed but have used digital multimeters for years). Ironically, the cheap Harbor Freight multimeters are quite accurate as long as you toss the leads that come with it and replace them with a better quality lead on Amazon, costing about as much as the multimeter itself (even then it is still cheaper than the next higher priced meter that has the wide variety of modes that the HF one has). I like the lead clones intended for Flukes, you do have to cut back the plastic shielding around the prong where it goes into the meter to make it work but once you do that it is quite accurate.

[@ThinklikeTesla]

What is the internal resistance of the meter itself? What is the full-scale voltage...maybe 1.6V?

[@JulianIlett]

A few hundred ohms I believe.

[@ThinklikeTesla]

@@JulianIlett It would be possible to calibrate the analog scale to read internal resistance. (Especially if you aren't using the 9V side, which would have a different scale). Sharpie away!

[@sonic2000gr]

The load on the analog one for the 1.5 V input is way to high with that 3R9 resistor. A 10R or 15R would be much more reasonable for a typical AA cell load. And of course the virtually unloaded digital one is not very useful.

[@pinterelectric]

Can you put your meter in series and measure the current draw of each unit?

[@andygozzo72]

you can work it out with a calculator for the analogue one , or on my plasplugs branded one, it tells you the load current on the rear label, 375mA for 1.5v, 40mA for 9v,, the 375 is probably reasonable for 1.5v but i think 40ma too much really for 9v PP3s, as most devices using them will draw 10mA or much less ... also tells the voltage levels of the coloured areas on the meter

[@lmaoroflcopter]

Think I prefer the analogue meter. Instant results when you're just checking if your battery is good. If I need an absolute voltage, I'll use a multimeter. Edit: ah... you have a project in mind for them. :)

[@brendonwood7595]

I have the analogue one and its a good quick go/no go

[@lmaoroflcopter]

RE: the differing voltage I would not be surprised if precision is affected by low voltage if the power for the meter is derived from the cell under test.

[@brendonwood7595]

It's probably the tolerance of the resistors used internally. 0.02 of 3.3 gives about 1/2% error.

[@andygozzo72]

i have 2 plasplugs branded things like the analogue one, had them many years(20+) , it has a label on the back to tell what voltage level the meter indications correspond to, and the load currents, batteries should always be tested with a 'reasonable' load

[@andygozzo72]

havent opened mine up but i bet uses 'proper' resistors, not smd 😉

[@markclark787]

I have a Pro and the wire on the slide keeps breaking, going to replace it with quality Silicone hook-up wire

[@edwardfletcher7790]

The digital tester is excellent, but the internal slider wire breaks a lot because it's super cheap quality. I've had to fix mine twice.

[@michaelkaliski7651]

For voltage monitoring of multiple batteries, an Arduino and digital display would allow simultaneous monitoring and comparison of all cells. These quick test meters are not suitable for long term monitoring and the drain they put on a battery is unacceptable except for the briefest period.

[@RobinRastle]

Those digital ones draw 20mA, but remember you need 4.000v display for Lithium cells . you only get 3digs ie 4.15 from the end pp9 contact, not very useful, better dvm available 5digs for precision and adjustable , but you power up with a pp9, much more useful

[@hi-tech-guy-1823]

I Would go For Open Source "LongMons" on a 2 wire TTL Serial Daisy Network ELERIX Cell / 123ELECTRIC BMS123 Smart Gen3 - Single Cell Module / Batrium LongMons

[@TKomoski]

Howdy 🤠