Review on Goupchn Parasitic Drain Tester & Car Blade Fuses Assortment Kit - 6 Colors | Automotive Battery Testing by David Guliford

Although the battery terminals are strong and durable, this device cannot bypass the ammeter to protect it when first connected to a high surge battery under test. It took me at least two weeks to understand failure mode. I had to order a competitor tester (Lisle 64970 Parasitic Drain Tester) to confirm the suspected problem. In fact, the competitor's tester performed as expected, protecting the ammeter during critical power surges that occur before the vehicle's modules go into sleep mode. I can only assume that the first tester is either defective or not perfectly designed.