KONNWEI KW208 12V Car Battery Tester, Battery Load Tester Automotive 12V Alternator Starter Tester Digital Auto Battery Analyzer Charging Cranking System Tester for Car Truck Marine Motorcycle Boat

Amazing for the price. You won’t be disappointed! Works straight out of the box, with no batteries or charging needed since it’s powered directly from the car. The instructions aren’t the best, so for those who might not know: connect it to the car by attaching the Positive (red) clamp to the positive terminal of the car battery first, then connect the Negative (black) clamp to the negative terminal on the battery. It can test batteries both in and out of the car. The device will power on once connected, and you get three options for testing the battery with step-by-step instructions. The three options are Battery Test, Cranking Test, and Charging Test. The Battery Test will determine the health of a battery, the Cranking Test will measure the battery's ability to start the engine, and the Charging Test will measure the voltage of the battery while the vehicle is running to determine if the battery and alternator are working. If you think you have a bad alternator, use this device first and run through the tests. It provides straightforward results (as shown in the photo) that tell you if the battery is good, needs to be replaced, or if the alternator has no output. Couldn’t recommend this device enough

I bought this to check the batteries in my cars and it works great. No more going to the auto stores to have the battery, alternator and charging system checked. This tester does it all and very easy to operate. The price is great as well. I'm very satisfied.

great price point and it works great.

We have 3 cars and batteries are 2 years old. We live in desert climate so cold and heat really wear down batteries, typically lasting 3 maybe 4 years. I tested all cars and it should one car was about 50% charged (car doesn't get driven much). Second car which is driven practically every day was about 60%. I bought a trckle charger and both cars recharged within a day. This tester saved me trips to the auto store for testing. Easy to use and a must Car tool to have.

This battery tester is compact, intuitive, and seems to produce repeatable results. Haven't tested the starting and charging readouts, but I've tested a few batteries and it seems spot on. One caveat is that in my car with a trunk-mounted battery, reading from the hood terminals (using the in-car reading option) produced a SOH (state of health) reading of 50% with instruction to replace, whereas reading directly from the battery produced a SOH of 90%. Not a fault of the reader as the long cables going from the battery to the remote terminals adds to total resistance and thus reduces the health rating, just a warning to those with similar setups to avoid an unnecessary battery replacement.

Worked well! Used this to test my battery. Tested battery while connected and disconnected. Very accurate and and a good buy!

Very easy to use. Just clamp it on and follow the on screen indications....and boom you know what the status of your battery is. I thought my battery might be dying cause the slow sound of stater.....but this device said battery OK. took a long drive to charge from alternator and all is good.

This works pretty good, but it doesnt have a case and it seems like it will need one b/c its light weight and plastic. It is very bright which is really good

MUY BUEN PRODUCTO

As user Chafik said this doesn't give the correct SOH or SOC because it isn't taking into account the temperature. For example: I used this at +5 deg C today and it was reading 12.49V. But when I ran the tester it was saying my SOC was something like 68%. Why? That isn't remotely correct. A battery at +5C has a max charge of 12.501V meaning my SOC was closer to 99.9%. It was reading my CA as 760A and my CCA as 560. Bear in mind neither of those numbers are the true CA or CCA since this device doesn’t correct for temperature. You can estimate your CA and CCA using what this device gives though. It’s fairly easy using excel. CA is determined at 0 deg C and CCA determined at -18 deg C. CCA = CA/1.25 (which is all this device is doing when you switch between CA and CCA modes). Ignore the SOC and SOH %’s this device gives they are irrelevant and incorrect. So go in excel and plot your x-axis as temperature. Test your battery in CA-mode for your first data point. So for me I put +5C as 760A. and “CCA” is 18C lower than CA so I put -13C as 560A which I got by testing my battery in CCA-mode. Plot a trendline and you can calculate your true CCA and CA. My true CCA is then 504A and my CA is 704A. The device was telling me my SOH was 100% but in reality it’s closer to 97% since my battery is rated as 520A CCA. Taking more readings would make it more accurate of course. Update as of December 2025: Still using the same product today. Still works great. As long you plot the data as I mentioned above with x-axis as temperature, y-axis as amps, you'll get the right data. Just a tip: you need to let your battery adjust to ambient temperature. Lead acid battery containers are ABS which is a bit of an insulator. If you turn your car on, boost your battery, or charge your battery, the liquid in the battery will be hotter than ambient thus skewing readings even if you do the corrections as I noted. I see a lot of negative reviews and most seem related to not taking into account as to how much temperature affects battery chemistry. A hypothetical battery fresh off the production line with brand new lead plates charged to 100% will read as 0% health, 0% charge at -55 to -65ish celsius (the freezing point of battery acid). You either wait for ambient to match CCA or CA or you plot some graphs.

Lo he probado en varias baterías y funciona perfectamente, sencillo de utilizar y muy fiable. Una manera rápida de checkear una batería 12v de manera fiable. Complementario a otro probadores como puede ser el densimetro y comprobador de alta corriente para testesr la descarga.

L'oggetto funziona bene, in manuale è scarso, ho lasciato la lingua inglese anche se nel menu esiste l'italiano. Ho testato alcune batterie, quelle che sapevo leggermente fiacche sono state testate come da sostituire. Direi che ci siamo. Con un video su Youtube ho trovato come testare le batterie degli ups, opzione che mi servirà molto al lavoro. L'oggetto è di plastica senza gomma di protezione, applicherò della spugna sottile da coibentazione con diadesivo per proteggerlo. Al momento sembra ok. Se il display si accende ma non compare la tensione della batteria significa che il contatto sui morsetti non è buono, dopo aver riposizionato tutto ok. Aggiornamento, eseguito test a 40 batterie nuove AGM pronte da montare su UPS, sono rimasto sbalordito, come da foto, letture perfette ci sono piccole variazioni ma è normale. Lo consiglio alla stragrande!!!

This product is damaged please kindly guide next process of warranty