A BMS can also help during discharge by signaling for load disconnection when individual cells drop below their minimum voltage. Cells discharged too deeply can be permanently damaged or, at minimum, have their capacity or cycle life permanently reduced.
There are no known Li-ion BMS power conversion products (inverters with chargers, and charge controllers) for the residential RE industry (although Clean Power Auto does have a solution for RVs and boats). The missing feature in standard power conversion is BMS cell monitoring and the available RE equipment can’t modify charging characteristics to handle when some cells have reached full capacity and other cells have not. Reading the voltage of the entire pack of cells is not helpful, since there’s no means of knowing whether or not some cells have already reached their capacity. Available charge controllers can’t adjust current on the fly to match the BMS’s ability to shunt current as cells start to reach 100% SOC.
If power conversion equipment with provisions for BMS become available, then LFP batteries can be useful in RE systems if:
LFPs can definitely help solve some residential RE storage problems. But perhaps a better question is, “Is the residential RE industry ready for LFPs?” At present, the lack of BMS integration in residential RE power conversion equipment is the biggest hurdle. Once LFP-compatible products become available, then LFP batteries will find a home in many RE applications, especially off-grid and mobile.
After earning his electrical engineering degree, Randy Richmond worked for the telecom industry. In 1999, he founded his own company, RightHand Engineering LLC, which makes products for monitoring RE systems. Since then, Randy has earned his professional engineer license and also offers design, test, educational, and consulting services for Li-ion-based power systems.