Your cart is empty.
Your cart is empty.Pamela K Steinback
2025-09-03 18:09:32
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.
Leo M
2025-07-02 13:35:14
I've been having some doubts about my fairly new car battery (Interstate, 700CCA) recently and wanted to make sure I test it before taking it back to the store.I am aware that batteries will lose charge if the car is not used for extended periods of time (which is my case due to WFM for months), but I was thinking that it would take much longer to a new battery to get there, maybe at least 1-1.5 months, especially in nice weather. I have been driving my car about every couple weeks or so, but mainly short drives. I thought that maybe the battery I picked did not quite happen to be the pride of Interstate product quality.Since I've wanted to own one of these battery testers for a while now, I figured that this situation would be a good time to get one, so after looking through several models to get familiar with the common feature set offer vs. cost, I settled to this Konnwei KW650, even though I was a bit reticent about the brand unknown to me.There are a bunch of these testers available, many of them offering similar if not identical feature package, even though the prices differ a lot in some cases, but the reasons that made me go for this one were the nicer processing speed and display, car starting voltage waveform capture and the software update capability.I figured that my risk would be minimal considering all the good reviews and Amazon's easy return policy.Well, I must say that I am very happy with my choice; this one is a keeper. After updating the software as soon as I received it, which was pretty easy to do BTW, I checked my battery and found that even though it was in a pretty badly discharged state, the tester showed that the battery was in very good condition and just needed a good charge. The state of health was 100% and the state of charge was shown to be only 10%. I have also tested a known weak battery I had stored until I can find the time to dispose of it. I tested it both before and after charging it, and in both cases it indicated a very low state of health and prompted replacement. I was planning to rent a professional battery tester and check the full instrument accuracy for parameters like the battery resistance, SOH, SOC, but at least from what I am seeing so far from my tests (lead-acid battery only) everything makes sense.The voltage measurement had only a small accuracy deviation of 0.06-0.1 max over a wide measurement range when verified against a professional meter, but that is meaningless for the purpose of this tester. The voltage ripple was also slightly off, but you can see some of that even when comparing more expensive equipment. The min/max voltage captures during engine start were also reasonably accurate.Considering the cost and intended purpose of the device, I believe that it is more than adequate for the job, and in my opinion, paying any more for a known brand would not be justified from the performance stand point. At least not for my home garage use.In terms of workmanship, I have nothing to object: It comes in a nicely looking plastic case, light weight and just the right size to hold with one hand, clear color graphic display with an easy and intuitive user interface. It has thick yet reasonably flexible 38 inch cable to protect the 4-wire Kelvin test leads, with solid connections to the battery connection clamps. I wish the cable were just a bit longer to reach the vehicle cabin when performing some of the tests more comfortably from the inside, like the car charging system. Not a deal breaker, because these tests are still easy to accomplish, but it would have been more comfortable that way.Now the one feature I was hoping to have on this device, was to be able to factor in the battery temperature into the CCA measurement and SOC calculation, as temperature is a huge factor in battery performance. Again, not a deal breaker at this price for me, but since most higher end devices can compensate for temperature, I believe that it would be a great feature addition and a cheap way to gain an edge over the competition. I wouldn't expect the addition of a battery post temp probe/sensor (although I would actually pay for the cost difference) but at least by manually entering the batt. temperature during battery test setup.Since the software can be updated online, I am hoping that this feature can be added later, and perhaps along with some other good things in the future. Who knows, maybe Konnwei is listening.
Don Kirst
2025-06-07 16:59:57
Work's great I checked my battery with this device and it was easy to use and it was accurate it showed that I had a bad battery cell when the dealership said I had a good battery I went to Advanced Auto and got a better battery and warranty plus they installed it free. I recommend this device.
UJM81
2025-06-04 18:56:38
I got this for a truck I was working on & it turned out that battery was OK. A couple of weeks later the battery died in another vehicle. This came in handy. Even not connected to USB and with a battery voltage under 8 volts, it powered up. I input the type of battery and cold cranking amps (CCA) and it showed the battery was only at 3%. When I tested the replacement, it came in at 97%. This was a good value for a handy tool to have in my shop.
Andy Man
2025-05-31 16:58:19
Came in the original box, sealed. Work out of the box . Easy to use, plenty of youtube on how to use the tester. No complaints
Toymanz
2025-05-30 16:51:12
Battery Tester was everything it was described to be, packaged very nicely, looks very professional. No internal battery needed just hook it up to your car battery and it comes on by itself. Much better screen than those other testers out there, easier to read and gives you a very bright readout. Measures everything you could want battery voltage, cranking amps and charging status. I have tried a few of the others and this one is faster with the tests results. Unit has a great warranty and you can even update the software on it, unlike most of the others. Case is plastic but it is very solid, it has nice long cables on it and the alligator clips are really heavy duty with great bite. Instruction book is nicely laid out but honestly it is so easy to use you won't need it. Like the others there is no case but the box it comes in is very strong with a nice compartment insert, which is great for storing. This one has everything you could ask for in a tester, don't waste your time with the others. Seller is very professional they know how to take care of there customers.
Displaced Desert Rat
2025-04-25 11:18:40
This tester is so useful. I recently had to test, charge, and reinstall a car battery a couple of times because we couldn’t get t to the root of the problem right away. That’s what made me start looking for a tester that would tell me more than just the battery’s voltage.Without reading instructions or looking at all the tester’s option, I was quickly able to test the battery’s terminal voltage, the cranking voltage, and the car’s charging system. The tester only required that I input the CCA (cold cranking amps) of the battery being tested. These are usually the larger numbers listed on car batteries.There are other options to test AGM, SLA, and other types of batteries. I feel like this is so useful since I have just about every type of battery out there in kids’ toys, mower, alarm system, and UPS battery-backups. Another really useful feature is that the tester will tell you when something is normal or within a normal range. That’s great if you’re like me and have a hard time remembering specific details like that.Last but not least, I love that I can get firmware updates from the manufacturer (which btw I did). I imagine that like all modern electronics, bugs can be fixed this way, and new features or improved performance can also be delivered via the updates. Now the hardest part is deciding if I’m keeping the tester at home or carrying it with me in my truck at all times.
HCheung
2025-04-11 14:25:07
Easy to use and a quality product
S. Wish
2025-04-05 17:51:14
Works well. Nice and compact to keep in my tool box. Tried it on 6 volt and 2 volt batteries.
Jerzy Z.
2025-03-05 16:11:15
wszystko mi siÄ™ podoba
Jonas Lundin
2025-02-17 12:11:37
Lättanvänd och mkt bra instrument!
Partha Das
2025-01-24 17:33:36
New vs old model
Recommended Products