I have 4 12v deep cycle lead acid batteries connected 2×2 in series for 24 volts and running parallel in my PV system. I connected the Mazava HC02 battery equalizer and it immediately balanced the voltage of the 4 batteries. The product performs exactly as advertised for me, however I regret my selection. Knowing that the product works by observing the LED display is great but the HC02 display also consumes current. I wish that I had purchased the Mazava HA02 without the display. Knowing via the display that the product works is great but really unnecessary. My multimeter would display the volts easily and would not be a parasitic draw of current.
This is great product and performs flawlessly for my PV system. I should have chosen more wisely.