Overkill Solar

Overkill Solar BMS is outstanding. I had purchased sixteen brand new Grade A 3.2V 280Ah EVE cells and struggled to keep them balanced with my previous unit, even after three manual top-balancing attempts. Frustrated, I reached out to Overkill to explain my setup. They quickly confirmed that their BMS was fully compatible. My son ordered the 16s-48v version, and the delivery was incredibly fast—just two days. After wiring it up and charging the battery bank to 100% using solar panels, I was thrilled to see all cells remain within spec for the first time. The same held true when discharging to 20% SOC. This is a top-tier BMS. We are definitely buying more as we continue upgrading our system. Big thanks to the team at Overkill Solar!

Switching my BigBattery CNDR Elite to the Overkill Solar 16s BMS was a game-changer. I had been struggling with the original Battery EVO unit, which felt more like a prototype than a finished product. It barely functioned out of the box, misreporting capacity as 60Ah when fully charged and offering limited resolution on the LCD. To make matters worse, the Bluetooth module was dead on arrival, and despite BigBattery support promising a fix, the solution never arrived. Removing the faulty unit and bolting in the Overkill Solar BMS was incredibly straightforward. A bit of careful splicing for the cell wires, and I was up and running. The documentation from Overkill Solar is thorough and excellent, complemented by their robust app ecosystem. I tested both the iOS and Android apps, preferring the iOS version despite the small fee, and later integrated the USB module on my laptop for deep dives. The real win, however, is the connectivity. Unlike the original BMS, the Overkill unit integrates seamlessly with Solar Assistant, allowing me to monitor everything from anywhere. I even wired a UART connection to an Ethernet jack for flexible Bluetooth access. While having a second UART port would have been nice, I’m not complaining. The system works perfectly, and that’s something I can’t say about BigBattery’s support. They threatened to void my warranty just for swapping the BMS, which felt like a bitter pill after a year of dealing with a half-broken unit that their warranty didn’t really help with. If you want a reliable BMS with solid communication, Overkill Solar is the way to go.

I’m thrilled with the Overkill Solar BMS. Bluetooth connectivity was flawless right out of the box. What really stands out is the seamless integration with Louis van der Walt’s driver for Victron Cerbo GX, which eliminates the need to purchase an additional smart shunt. Excellent product from the team. Greetings from Austria!

I’m thoroughly impressed with the Overkill Solar BMS units. I currently have five installed and they are all functioning flawlessly. When my inverter suffered a catastrophic short circuit across the battery terminals, the BMS correctly isolated the charge port, protecting my battery packs from any damage. Based on this reliable performance, I’m sticking with Overkill Solar for future projects. Highly recommended.

I recently picked up the 16S from Overkill Solar and it’s been a fantastic experience. The unit powered on immediately and performs exactly as expected. I was really impressed by the Bluetooth connectivity, which is rare to find at this price point. Considering it comes from China, the build quality is genuinely top-tier. However, having a USA-based team like Overkill makes a huge difference; you get that extra level of care and attention that you often miss with direct overseas orders. The colorful, single-page manual is a smart touch—it clearly explains what to do if you make a mistake, so you aren’t left stranded. Plus, knowing you can easily reach customer support for help adds a lot of peace of mind.