BT-168D Battery Tester

BT-168D Battery Tester
Links below:
Interesting and fairly useful little batter tester (I guess just measurer). So much so, I bought one for work too.
Banggood
'Aneng' BT168d Battery Tester - £3 - uk.banggood.com/custlink/mvDD...
Aliexpress
BT-168d Battery Tester - £2 - s.click.aliexpress.com/e/_s872fT
Amazon UK and US BT-168d Battery Tester
UK - £3.5 - amzn.to/37jWojK
US - $6 - amzn.to/2uoSYhm
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[@ThisSteveGuy]

You want to get the "BT-168 PRO" instead of this one. They both look nearly identical but the PRO supports batteries ranging from 1.2v up to 4.8v (and 9v), and it can fit an 18650. You don't need to get the Aneng one, the important thing is that it's the PRO model. It might be a couple bucks more but it's worth it.

[@beargun42]

I bend the metal on de red slider a bit, so it has some springiness. That really helped getting a good connection. I put a screwdriver underneath the metal, in de middle, and bend it up a bit. Does need much.

[@hoangnguyendinh291]

I was thinking about setting a lot of battery trays with mini digital voltmeter modules for reading battery voltages faster. But it takes a lot of space. So I also purchased the BT-168D. It's portable and saves a lot of time compared to using a multimeter to read battery voltages

[@marcrives279]

5:58 You can pinch red cable inside, in the middle of the slider. That way, no more stress on solder joint on this side. I have one tester, I opened it immediatly to make that change!

[@YH-rd4kt]

5:58 wow i surprised you really guessed it! I was looking for repair information of bt-168d because it suddenly don't work, found out that slider part you exactly point out was disconnected! And for somebody may have lcd display don't shows voltage correctly, but showing '18C', all you need is just take out circuit and LCD panel, adjust contact between them, and screw in tight. At least i fixed it this way.

[@WOS1962]

Thanks. I have a BT 168 pro and I've tested A23 barratry 12 V by mistake I notice a problem in reading the digits, do you think the appliance is broken??

[@johncoops6897]

There is an inherent design error in these units that makes the 1.5v mode very inaccurate and non-linear. There's a boost circuit to power the processor, and also to put some load to the 1.5v battery. When you connect to the top 9v connections, the boost circuit is bypassed. Hence the problem... a diode is used to stop the 9v from reverse-powering the boost converter. That diode has a forward voltage drop that affects all 1.5v measurements and they have tried to average out the error with dodgy input voltage divider values. You can fix the inaccuracies by removing the diode and replacing it with a physical switch then adding a trimpot on the voltage divider to allow calibration. Now note that the boost circuit WILL fail if you run Lithium cells into the 1.5v side. So instead of switching between slide and top connections, make the switch be for 3.3v (no boost) input. Doing this mod plus adding some load resistors and tweaking the voltage divider will result in a very accurate little tester.

[@johncoops6897]

Here is a tech page that explains the issue, however it proposes an semiconductor switching IC and not bypassing the boost circuit at all for the slider connections... ka7oei.blogspot.com/2014/04/making-cheap-chinese-battery-tester.html?m=1 I decided to use that research to design my own solution that uses a manual switch to simply add or omit the boost circuit. In that way it allows me to measure lithium 14500 (mainly LiFePO4) cells etc using the slider contacts.

[@Ni5ei]

Very interesting! Just wondering, since the diode is on the 9V top connection side, why will the boost circuit fail when using Li-Ion on the slide terminals? [edit] Oh wait, I have the Pro model that can measure 1.2 to 4.8 V on the slide terminals. So does that model suffer from the same problem? [/edit]

[@johncoops6897]

@@Ni5ei - On the "Non-Pro" model: From memory there is a diode is on the 1.5V side as well - in other words, both inputs run through a diode, and the diode(s) is what causes the voltage errors. It affects the 1.5V a lot more than it affects the 9V measurements. The Boost circuit (in the "non-Pro" fails because it cannot handle the input voltage being above about 3V, and it literally burns out the Inductor. The new PRO model is excellent. It doesn't seem to suffer any errors or problems. I bought two of the PRO after I got sick of trying to get the "non-Pro" to read accurately. My two PRO's measure slightly differently, but it's within a few percent. They could be tweaked by adding trimpots around the voltage divider resistors on the input to the measurement circuit.

[@Ni5ei]

@@johncoops6897 Thanks so much for responding this quickly (the post I responded to is 2 years old). Great to hear the Pro model is way more accurate. I do plan to install a few resistors and switches to create a load though.

[@johncoops6897]

@@Ni5ei - get some 26 AWG fine stranded silicon cable and replace the wire on the slider bar. Also use a fine stone or wet/dry sandpaper and smooth all the burrs on the slider and track. Those make it nicer to use. And dont tough the zebra strip for the LCD with your fingers LOL

[@DubiousEngineering]

It is indeed nice to have a digital reading... It may be nice to have a spring on the handle - not essential... I should get one of these for my battery draw. I was worried about it putting next to no load on the battery, where a meter loads it just a little and may offer a slightly more realistic reading - no biggie though! Next question... can you put a 4.2v LithionCell in it? HA! Answered!! not an 18650!! Too big... Paperclicp may sort that... Nice to see this thing!! Thanks Mr Watts!! All the best!

[@DavidWatts]

You could shove a fat LED after the boost circuit to add a little more load. I think ~10mA is good enough for a rough indication of the battery state. Not suggesting it is a replacement for a properly calibrated meter just more convenient for a quick sense check.

[@IlbuonvecchioRay]

so it s battery less, it uses the energy during the measuration? Nice

[@jimlad01]

This tester seems to read '1. -' (One dot minus) on all my NI-MH rechargeable AA's, whether they're charged or not. Faulty? Any clues?

[@gn0st1c]

E30F is HT9261-30PX (dc-dc booster)

[@mikeinpcola5543]

Cool video and battery tester. Do you by chance know if this tester is just reading the DC voltage, or is there some kind of small load test applied? Thank you.

[@DavidWatts]

Very little load is applied as far as I recall, just enough to power the device. You could add a resistor across positive and negative to get a better reading of the true voltage though, you raise a very good point.

[@mikeinpcola5543]

@@DavidWatts Thanks for reply...reason asking is you know how just using multimeter on car batt...might say 12V but that means nothing for there was no load, but with load tester, car batt may say 11V at which point you have a problem. I think the same on all these analog or even digital testers for disposable batts, they may give false security if they don't load test.

[@sadfur8728]

The tester does apply a load to the battery, and it's basically a constant power load, which will ramp up the current as the voltage drops. On my unit, the power draw is about 27mW at 1.15V, or 23.8mA. For 3.97V, the draw is 20.9mW, or 5.26mA. 9V port had a load of 5.5mA at 8.26V, or 45mW. You'll find it may not even turn on with marginal small button cells, because they can't deliver sufficient current at the low voltage. 30mA is a significant load for the tiny cells. Don't try to simply compare accuracy against a DMM because that's basically an unloaded measurement with a 10M ohm input impedance. That would do nothing in determining if a battery is actually usable or not, especially for lithium coin cells. With those, they'll pretty much always read near 3V, but can't deliver any usable current. This setup is actually a good screen test for batteries. If you need a guideline as far as what is good or bad you can look at the chart on the back, but you really have to consider what device you're using and what kind of cell to set up your own thresholds for replacement.

[@kjur18]

I think it might boost voltage to like 5V and lower it with this small sot23 voltage regulator. What you measured is probably output of U2, not U1.

[@DavidWatts]

Could well be, I decided not to trace the whole thing out as it really is just an indication device rather than something precise.

[@Hasitier]

kjur18 those were my thoughts as I saw the video. You could verify this easily by measuring the voltage after the 9v input protection diode while powering it with about 1,5 volts on the slider input. I also have one of those since years. Maybe I take a look into it if it’s the same inside?

[@jort93z]

I have the analog version of it, the BT-168. Works fine as well. Theres also a scale on the back that lists the voltages for the ranges. it says low/replace: 0.9V, Good/low(i think the mean good/replace): 1V. So it you can kinda guess the voltage accurately enough. If you just wanna quickly check a battery thats the tool for the job. Measuring batteries with a multimeter is pretty pointless. An empty battery will often show a normal voltage when theres no load.

[@beargun42]

jort93z me too. There is actually a 5ohm resistor inside, across the battery to provide a load. Quite a heavy load, which really weeds out dead batteries. Not sure those few miliamps on the digital version will do that.

[@jort93z]

@@beargun42 The digital one has a resistor too. It is labled L1 if you check the circuit board in the video. Also, mine has a 4 ohm resistor for 1.5v and 215 ohm for the 9v. At least it says so on the back.

[@Hasitier]

jort93z I think L stands for inductor. Which is needed for the boost circuit. I have the same and will take a look into mine to find out more.

[@jort93z]

@@Hasitier Looks like a big old resistor to me. I am fairly sure that the digital one would also use some sort of load though.

[@IliyaOsnovikov]

I used to have that BT-168. And it might be even better than the newer models. Because the the old was providing real load for the batteries under test but the new models don't.

[@IliyaOsnovikov]

That tester does not seem to provide much of the load for the cells under test. I've read that the old unit BT-168 with analog indicator was drawing as much as 375 mA from brand new 1.5 V batteries.

[@sadfur8728]

375 mA ? That seems like a decimal point was dropped somewhere because it was probably more like 37.5 milliamps. 375 would be way too high for a battery test. The BT-168D that I have draws a load of about 28 mW, which is a reasonable load for general testing.

[@adiands850]

The analogue 168 unit loads down the cell with a 3.9 Ohms resistance.

[@websitesthatneedanem]

I have one of these too, I wish it drew a more substantial current so as to test the battery under load.

[@DavidWatts]

There is plenty of space in there to hack in a couple of LEDs ;-)

[@neogeo8267]

@@DavidWatts or just a resistor of sufficient wattage

[@LucIan-er2ir]

paralel resistor 10 Ohms it would be fine...

[@sadfur8728]

The one I got for the princely sum of $2.68 from Temu seems fairly decent in that regard, with a constant power loading, where the current draw drops with higher voltage. It's not a simple resistor load.

[@sadfur8728]

You could probably add a load on the 3V output of the internal DC converter to increase it beyond what it draws now, and allow it to still operate with a constant power load.

[@07786013535]

how am i suppose to know if the battery is fully charged dosent say good bad only set of numbers

[@ibringthelastwords1358]

Mine can fit 18650 batteries and the brand is aneng BT-168 pro 😁

[@TheEmbeddedHobbyist]

interesting to know how you can tell the charge state of a battery with a small load and a voltmeter. As the curve is often a slight voltage drop then a shallow slope and a sudden knee and big drop off. OK as a simple quick test but not to be trusted much.

[@DavidWatts]

That is where the mental arithmetic I mentioned comes in. We tend to know our batteries, how old they are and what kind of current they can deliver. It is called a battery tester but I would merely use it as a 'measurer', what that measurement means is down to your knowledge of the battery and it's chemistry.

[@LucknowEventFriends]

Can they survive reverse polarity? If someone inserts the cell opposite way will it survive?

[@DavidWatts]

I can't quite recall the circuit but I have reversed the polarity many times on AA batteries and it is fine. I think there is a physical bit of prevention for 9v batteries.

[@anant0089]

What brand is lithium cr2032 u used and it showed 4v they r suppose to be 3v ? And what is difference standard and lithium?

[@DavidWatts]

Renata rechargeable I think, they wouldn't be 4v under proper load. 3v for standard ones though and the rechargeable lithium have like 5% or less of their capacity at above 3.7v

[@pault6533]

UPDATE WITH ANSWER: When measuring a 9V battery, I need to make sure the slider terminals do not make contact. When the + and - are connected together when pressing the unit against the rectangle battery, the 9V reading will be reduced by approximately 1.4V for my BT-168D. Strangely, the ANENG 168Max I own has these terminals contacting by default and open/closed doesn't make a difference. I will put a label on the unit so I don't forget. PREVIOUSLY POSTED: Mine reads 9.06 V for an instant when first pressing the battery against the side, but then switches to 7.61V reading steady. Why do you think it does this? Works stable on the slide terminals.

[@fokcuk]

Can you add a load to a lcd model?

[@michelj.gaudet5048]

If you look closely at the back-side of the orange slider, you notice a small 'slot' of plastic, or nub, for the wire to be placed into, which will help prevent the movement of the CONNECTED AREA (soldered). So your concern of the connection failing over time is due to your not noticing that the wire should be replaced BACK where you pulled it from. I would use a dab of any proper glue onto the wire/nub slot when putting the thing back together... just sayin'. - lol

[@softmire]

what's difference with AN-168 POR testeur ?/thks

[@DavidWatts]

This one is not strictly meant for li-on batteries, the aneng one is.

[@AdamWelchUK]

C Cells, D Cells on the sea shore.

[@deedee_31]

first i love your accent and b you have a cool ass last name WATTS and you're working with wattages well not really light bulbs have the watts wattages lol well guess u now have to get a job working with light bulbs haha lol so cheeky mate lol

[@koolkiwikat]

Mine stopped working after a few months :(

[@thomasjaszewski64]

These days I find lithium settings invaluable. No 18650 blows it.

[@MaxAirGo]

The real Aneng Bt-168 does. It has a different red slider that extends enough for 18650.

[@justanant1]

aa recharge r suppose to be 1.2v why does it show 1.30 etc

[@DavidWatts]

A fully charge NiMh cell will be around 1.4-1.5v when testing the voltage with a minimal load. It will drop to its nominal voltage of around 1.25v on a reasonable load very quickly.

[@justanant1]

@@DavidWatts oh that is interesting ty

[@patricksweetman3285]

Thumbs down on the device because of ratty contacts and no spring.

[@neogeo8267]

Needs electroplated gold contacts. Sounds like a video request to me! Electrochemistry is fun.

[@patricksweetman3285]

@@neogeo8267 Yes, gold-plated and textured with spikes.

[@pault6533]

Try using a pencil eraser on the device and the battery terminals before use. You can also apply some contact protector on before putting it away. Even if you plate the terminals with gold, the battery contact will continue to be oxidized nickel, which requires significant pressure to overcome contact resistance. This is why devices that use these cells have stiff springs. The pencil eraser doesn't get rid of all the oxidation, but it will remove some of the other environmental contamination that might also be present, even if it looks clean it this layer of nonconductive material is there obstructing good contact.

[@neogeo8267]

Seems like a buck boost regulator