







🔧 Power up your diagnostics with precision and pro-level insights!
The KONNWEI KW650 is a versatile and highly accurate 6V/12V battery tester designed for automotive, marine, and lawn equipment batteries. Featuring advanced STM-32 chip technology, it delivers over 99.5% precise results within milliseconds. Its unique one-key voltage waveform analysis helps both novices and professionals diagnose battery and in-car system issues in real time. Beyond battery testing, it evaluates starter and alternator performance, making it an indispensable tool for proactive vehicle maintenance.













| ASIN | B088CP8VPC |
| Best Sellers Rank | #440,457 in Automotive ( See Top 100 in Automotive ) #297 in Battery Testers |
| Brand | KONNWEI |
| Color | KW650 |
| Customer Reviews | 4.4 4.4 out of 5 stars (1,386) |
| Date First Available | May 9, 2020 |
| Item Weight | 13.6 ounces |
| Item dimensions L x W x H | 0.79 x 2.76 x 4.92 inches |
| Item model number | KW650 |
| Manufacturer | KONNWEI |
| Manufacturer Part Number | KW650 |
| Measurement Type | Voltmeter, Ammeter |
| Min. Operating Voltage | 8 Volts |
| Power Source | Battery Powered |
| Product Dimensions | 0.79 x 2.76 x 4.92 inches |
| Specification Met | [Cautious] Shenzhen Jiawei Hengxin Technology Co., Ltd. Internal Certifications Or Quality Standards |
| Style | Voltage Tester |
| Upper Temperature Rating | 70 Degrees Celsius |
| Voltage | 12 Volts |
P**K
Saves money when you have a lot of vehicle/lawn equipment batteries
Simple to use and gets the job done. Wanted something that was not overpriced, with good features and the ability to test a variety of batteries, alternator, and starter condition. After using this on several vehicles and batteries I have learned how the resistance of the battery and expected life of battery work. The feature for running voltage and ripple current graph have become very handy during load test. The starter crank test and time have helped find two starters that needed to be replaced. The screen is easy to read, menu functions are simple to navigate, and battery clamps / wire are of good quality.
H**R
Great battery tester
Works as it should, and you don't need batteries!
S**E
It provides useful data but it needs some work to be a polished product.
I followed the directions and downloaded the "BTlink" software off their website. Since it was a .ra file I had to load a unzip tool to get the software unzipped. WIndows had security cows while trying to load Konnwei's software and after doing so I ran a couple of virus/worm scans and it appears to have not loaded anything detrimental onto my computer. The software then said to push the "OK" key while connecting the USB cable to the tester to get it to go into "Update Mode". There is no "OK" key on the battery load tester so I guessed that by pressing "Enter" would get me where I needed to be and it did. I ran a battery of tests on my battery. I wanted to do the quick test but it requires that you know how many Amp-Hours your battery has, not cold cranking amps. Most flooded car batteries do not have Amp-Hour ratings on the battery and thus I could not do the quick test. I ran the in-car tests which tested the battery "in-the-car" and gave the results as shown above. I also ran the charging test which showed the alternator charging the battery showing a small trickle charge voltage. I did the starting test which is captured in the waveform above which I turned off the engine and started it back up. The downward spike is the drop in voltage as the starter is starting the vehicle. With the BTlink sofware you are able to download the two items shown above. It would be nice to have them together on one page instead of printing two. The waveform did not print and must be saved as a bitmap first and then can be printed. This is done with the tiny icon up in the upper right hand side of the page. The book may describe this, but it should be listed in the software. or the icon a heck of a lot bigger. I liked that the trickle charge could be seen in real time, but it was not saved nor could be printed out. It would be nice to have that information so as time goes forward it might help indicate that the alternator brushes are wearing out. I also like the waveform that was being save in real time. I gave it four stars because there are somethings that would of made my experience better if the tester could quick test using CCA and update the BTlink software to not be "OK" but "Enter". What is it with the green in the test printout. Black would be better. I do like that the information can be printed for further reference. For the price it will be a nice addition to my garage.
M**E
Find out what kind of shape your car battery is in
I used the Konnwei battery tester on two cars (one very old, one brand new), and 4 small lead-acid batteries used in a UPS (Uninteruptable Power Supply). The new car had a battery that was in very good shape, but didn't have much of a charge, as it was sitting at the dealer lot, and was shipped from abroad. The new car was a 2019 Hyundai Kona with a 60 AH, 640 CCA AGM battery, and it was at 100% SOH (State of Health), but at 56% SOC (state of charge). After charging it, the Konnwei unit showed the charge up to 98%. It is important to keep lead-acid cells near full charge, as if they are allowed to sit partially discharged, they will form sulfates on the plates, shortening the life of the battery. The second battery, on a 2003 Hyundai Santa Fe was about 3 years old, and the car isn't driven much, so the battery loses its charge because of typical parasitic current draw from the on-board computer, clock, radio, etc. The pictures show the SOC, SOH, and a photo of the Konnwei connected to the battery with a disconnect switch on the battery. While the battery is good, it shows 82% SOH, as the photo was taken at 28 degrees Fahrenheit, and lead acid batteries don't have as much 'get up and go' at lower temperatures. The four small lead-acid batteries that I checked that came from a UPS were 7 years old, and only showed about 2% SOH, so they were ready to be recycled. I also like the feature where you can get an 'oscilloscope' style display (graph of voltage over time during the car starting up), and so you can see if the battery is getting near end of life, or is still good for a few more years. Both batteries in both of my cars showed good starting performance at 30 degrees Fahrenheit. This is a must-have for folks with cars more than a few years old, as you will know when to replace the car battery before it gives you trouble, and leaves you stranded somewhere. This unit uses a new technology where it judges SOH from the rated CCA (cold cranking amps) and the internal resistance of the battery. An excellent tool to add to your garage.
J**S
facil y pratico
T**T
Usage pro, très efficace
R**S
Collegato direttamente alla batteria e preciso. Poi fare pure test della carica batterie con vizualizatione tipo oscilloscopio a vedere la forma del segnale. Lo uso insieme a "Doctor 50-Telwin". Per me va bene. Grazie.
J**.
wszystko mi się podoba
P**S
New vs old model
Trustpilot
3 days ago
5 days ago