Review on Revolutionary Maxmartt Battery Charging Irrigation Protection: Unleash Optimal Efficiency with Advanced Technology by Jeremy Carpenter

I noticed these cute little boards because of the thread on Infinity Sphere.com about adding an extra battery to a very powerful electric mountain bike. I damaged the extension's BMS and the internal BMS worked twice without either of them. I use it so my 30A booster doesn't draw current from the indoor unit, which can draw 275A. Since the indoor unit has a significantly lower internal resistance, my load is mainly powered by the main unit with two in parallel. Whenever I run out of capacity, the expansion pack dumps into the main pack until they line up. When charging in the field with only 1 charger, I connect between the ideal diode and the booster block. If it's already balanced, the indoor unit will also draw the lion's share of the current from the charger, and even if it's larger (28.6Ah vs 17.5Ah) it will charge faster. If it weren't for this diode, once the internal battery gets a good start, especially if I suddenly stop charging, the main battery will discharge very quickly into the booster, possibly exceeding the 30A the BMS can handle and well over the maximum safe charging current of 15 A. The diode also ensures that the regenerative braking current is only absorbed by the robust main unit. Since they seemed to be partly intended as heat sinks, I decided to keep the screw terminals but use my own ring terminals. To save space I turned them inside out so they were parallel to each other in the middle with the wires coming out of each back corner. I only use an 11A charger and rarely see more than a few amps between batteries in my log. According to Infinite Sphere they are good up to 20A without a heatsink, 30A with a tiny heatsink and/or little airflow, 50A with just heavy cooling. They are sold under many brands/names, they work great and are on the lower end of the price range. I proved their function by accidentally plugging a wire back in during installation. I couldn't understand why the main unit refused to use power from the booster, I thought it was DOA. No, it's just doing its job.