140 - Review of the Kaiweets KM601s rechargeable smart multi-meter with a serious safety problem

Подписаться 7 тыс.

Просмотров 3,5 тыс.

50% 1

Kaiweets has updated the KM601 with a rechargable version, the KM601s. The specs remained the same but they did fix a few of the annoyances of the original as well. Unfortunately the way the charge lead is connected creates a serious safety problem. I managed to kill my KM601s by leaving the charge lead attached while measuring mains voltage and I could have received a serious electrical shock. Despite all improvements, I don't recommend the KM601s.
After note: Kaiweets acknowledged the issue and promised to pass my comments to the design engineers. Also they send me a replacement KM601S.
My review of the KM601 which is practically identical but uses 3xAAA and therefore does not have this safety problem is here: h • #109 How good is the K...
You can support the channel by becoming a patron. www.patreon.com/user?u=45604138
As a patron you get early access to all my videos as well as exclusive content.
0:00 differences
1:25 improvement
2:09 fuses
3:27 charging
4:45 danger
6:14 its dead Jim
8:16 post mortem

Наука

Опубликовано:

12 июл 2024

Ссылка:

Скачать:

Готовим ссылку...

Добавить в:

Мой плейлист

Посмотреть позже

Комментарии : 33

@MANINDERSINGH-bw4ms 2 месяца назад

True analysis free from marketing.which is budget friendly as wel as accurate.i think zoyi zt 300ab or htc dm98 or of such similar kind. secondaly recharging batteies r creating trouble after long use brust or enlarged like ballon may damages multimeter body.if AA size has enough life then it is not good to think about rechargable battery and creat problems of charging and as u mention in ur valuable video. Thanks for vivid transparent analysis .👌

@Kaiweets 8 месяцев назад

Hi Heinz, I want to express my sincere understanding and appreciation for your concerns regarding product safety and your responsibility towards your followers. We sincerely apologize for not making it explicit in the product manual that using a lithium battery multimeter while charging is not recommended. We are taking immediate steps to rectify this by incorporating clear instructions on both the manual and product pages. Additionally, we will emphasize the importance of avoiding this scenario for all products equipped with lithium batteries. Regarding the $10 fuse, we would like to extend our options to you. Would you prefer a replacement fuse or a direct compensation for the inconvenience? Our primary objective is to arrive at a resolution that leaves you fully satisfied. Another important point I want to make is that if the fuse of any product purchased from Kaiweets is damaged during the warranty period, as long as contact our after-sales team, we will replace the fuse for free. This is our commitment to consumers. If you have any further questions, please let us know. Warm regards, Kaiweets Marketing Team

@TheHWcave 8 месяцев назад

Many thanks for your comments and the fuse offer. I hope we will see an improved KM601s soon.

@jordanthomas2210 7 месяцев назад

Wouldn't a dedicated charger fix this issue?

@TheHWcave 7 месяцев назад

@@jordanthomas2210 Yes, it might, if you use a charger with an unusual plug into the meter, so you "have to use it". And of course the charger circuitry internally would have to be isolated from the mains. Both measures cost way more than any manufacturer is willing to spent and people (me included) don't like "special" chargers. Consider that you may be out and about with the meter and run out of battery and left the charger at home or, worse, lost it.

@E85_STI 3 месяца назад

I just bought this meter but just so I understand what's going on so the danger here is not to use the charger as a passthrough charger while trying to use the meter for work right?

@ShepFM Месяц назад

I mean, top class service for them recognising and attempting to rectify the issue, as a beginner, i will be purchasing this meter and obviously not using it while charging. Great review and thank you for making us aware of the risk.

@johndevires5911 8 месяцев назад

Wow, that was a close call! Glad you are OK, thank you for this video. 👍

@t1d100 8 месяцев назад

Great investigation, find and Don't Buy Warning.

@davidv1289 8 месяцев назад

I like the updates and the rechargeable battery, but that is a serious design flaw! Thank you for finding this issue and reporting it to us and the manufacturer. Regards, David

@E85_STI 3 месяца назад

is there a way to turn up the brightness? I notice while outside this isn't very bright vs your standard black numbers on a regular multimeter.

@user-ig4xq8ng7u 5 месяцев назад

GVDA gd128PLUS same problem?

@TheHWcave 5 месяцев назад

Yeah, I am seeing more and more reviews of rechargeable multi-meters that have this problem. Nobody of the RU-vid reviewers seem to point this out let alone test it.

@diydantex6150 8 месяцев назад

Thank you very much for the safety warning. I will continue to use the meter but will be careful of the shock hazard.

@simontay4851 8 месяцев назад

They should (need to) be using an isolated DC DC converter for charging. Also, you should be able to still use while charging. If you (as in anyone, not you personally) wanted to use it and found that the battery is flat, you'd expect to be able to use it while charging. Other devices still work when charging. I have the OWON HDS2102S and i can use it while the USB-C cable is connected. The screen doesn't lock. The charging circuitry in this kaiweets multimeter needs to be redesigned.

@TheHWcave 8 месяцев назад

A isolated DC2DC converter would be best, I agree but probably making the meter too expensive. I have an OWON HDS272S and even there you have to be very careful in what you measure while it is charging. Basically when charging the input is grounded through the charger. If you accidentally touch the ground lead of the probe to Live, you will blow the scope up as well as the charger probably. Because sometimes I run out of battery on the OWON mid measurement, I now connect it routinely to a big USB powerbank. That way I can run it for many hours and still be isolated from mains ground.

@simontay4851 7 месяцев назад

But you wouldn't connect the ground wire of the probe to live, that would be really stupid. Ground is ground. Connect the device under test to an isolation transformer if you HAVE to connect the ground to something thats not ground. But you almost never need to do that

@TheHWcave 7 месяцев назад

@@simontay4851 I have no idea what you are talking about. What probe? Are you arguing how to use the KM601s in general or how I should have conducted my test? Anyway, the point of my test was to check if the meter was used to measuring mains with the charge lead still connected, whether it is safe to touch that dangling USB connector. The answer is NO because it is now live with respect to ground. This is a very dangerous situation, beginners may not realise. I looked at Aliexpress and other sites and it seems the problem is wider than the KM601s. We need more general awareness of the possible dangers of rechargeable test equipment. Help spreading this awareness, please.

@michael1 6 месяцев назад

Actually lots of devices don't work while charging, e.g wet and dry shavers - for good reason. It makes no sense at all to charge something whilst you're poking it into live mains. Really though this seems like a non-issue because anyone smart enough is just not going to do it. OP only did it to make a point. Anyone unaware shouldn't be playing with live mains in the first place (and will undoubtedly find some way of electrocuting themselves if they do so the 'beginners may not realise' doesn't make a lot of sense imo) I mean if you touch the probe while it's plugged into the mains you could get shocked too - does a beginner know that?

@TheHWcave 6 месяцев назад

@@michael1 Beginners are indeed the problem. Everybody in the comments seems to be concerned about using it while charging. I am not! While charging, the meter shows a display that indicates its not useable. OK, that does not prevent people from using the probes and stuffing them into mains, but I am willing to concede that this would be rare. My concern is AFTER charging. The charge cable is non-standard. If you loose it, or don't have it with you when measuring things away from home, your meter is dead. So the temptation is strong to keep it plugged into the meter and just wind it a few times around the body so you always have it handy... and now you are starting to measure mains... with an exposed USB plug that is now on mains voltage....

7 месяцев назад

Do you please have any idea, whether the new KM602 has the same design issue?

@TheHWcave 7 месяцев назад

I don't have one but looking at their web site it uses the same charge cable, so ... Be careful and make sure never to have this charge cable and probes plugged into the meter at the same time

7 месяцев назад

@@TheHWcave thanks for the reply, I have seen that too and I have the same suspicion. Will be looking forward for a potential review :)

@forfun8457 3 месяца назад

Advice please which multimeter to buy for the beginners?

@TheHWcave 3 месяца назад

I am getting asked this a lot and the answer is always it depends what you want to use it for. If all you do is electronics, say less than 60V and no more than maybe 2A (but not at the same time!) pretty much any multimeter will do. If you ever plan to use it for mains house wiring, go for a brand. It does not need to be a Fluke. Brymen are at least as good, but Amprobe or Extech are usually ok. You could also consider the house brand of big electronics distributers like Rapid, or RS (RS-Pro line). They are generally safe. For electronics, I would still recommend not to use "smart" meters as that often gets in the way or cause issues with measuring low voltages. They are getting better though.

@yannis92preloude 6 месяцев назад

On the uni t 179 and 181 you have an adaptive with a Jack and an insulated power supply charge the meters. The good thing on them with the charging adapter you cannot use the test leads at all that way you cannot let you electrocute yourself or blow up your meter.

@seant1418 8 месяцев назад

The correct way to test wether the usb cable would be dangerous if left plugged in would be to test for continuity between the input terminals of the multimeter and the usb connector. DO NOT PLUG INTO MAINS VOLTAGE AND THEN DELIBERATELY TRY TO SHORT MAINS VOLTAGE!!!! Additionaly, the outer metal part of that usb plug is not connected to any part of the barrel jack that plugs into the device. So I can see why the camera had to be "off" when the failure occured the way you described it.

@TheHWcave 8 месяцев назад

Yes, that is all well and good advice. I did try to measure the resistance as the video shows but because of the AUTO function continuously switching, the values were inconclusive. Measuring carefully(!!!) the current against ground was the next best thing. The camera was off for no other reason than what I said. If you are implying anything was staged or rigged that is completely wrong. All I did was push the green test lead firmly in (the banana plugs are a bit worn) and repeated the test I showed on the video. You will measure small AC currents even if there is no actual ground connection because of capacitive coupling

@JAKOB1977 Месяц назад

Thx for the video, but aint this meter like a 25 buck device, so its build to a price so how other meters to +500 to 800 dollar does it when charging like Agilent... arhh come on, be grounded.. at the end of the day.. it ain't kids that uses such a device but usually adults and you as the consumer also have a responsibility to not do stupid things that clearly ain't intended... like having a charge lead hanging loose when checking high voltage mains and even ignore the warning on screen and double dipping to counter the lockdown as come on, whats next.? you also have a responsiblelity.. when you wanna work with mains.. you need a certain skill and understanding of how things work.. just as, if you wanna work on mains voltage, then get a decent meter, not the cheapest ones form China.. use common sense.. The only item I got from Kaiweets/Habotest etc is the 35 dollar HT208D (incl. EUVAT) and that is mainly because of the inrush which were surprisingly okay both in DC & AC not least with the price in mind.