And now the future comes home! Our in-house developed BMS Joulie+ utilizes active balancing. The states of charge of a battery's cells are being equalized continuously among one another. That is to say, energy from higher charged cells will be transferred to lower charged ones. This results in 90% efficiency, compared to 0% with passive balancing. Additionally, active balancing increases life expectance of Li-cells by more than 30% due to reduced drift of characteristics. Increased energy yield from the charged battery is another positive side effect: with passive balancing the depth of discharge (DoD) should not exceed 70% to provide long life expectancy of the battery. Our active balancing allows for 80% DoD without reduced life expectancy - thus 14% more energy with identical rated capacity.

Joulie+ also enables communication of the battery with the inverter via CAN interface for standard inverters, as well as internet based remote monitoring of the battery independent of the inverter. In this process all relevant data like voltage, state of charge, temperature etc. will be logged and analyzed for each battery on single cell level. For instance, this allows for identification of an early seasoned cell of a battery, and arrange for its prophylactic replacement. Thus, a possible system failure can be avoided.

With internet-based remote monitoring you can observe the state of the battery and its single cells independently of the inverter. This enables early identification of problems, change of parameters and analysis of typical battery usage. Active balancing is specially beneficial for second life lithium cells. The system is capable of clustering, that is, several batteries with Joulie+ can be connected in parallel/series to increase capacity.

Regarding the lithium cells we also stand out from the usual market standard - lithium-iron phosphate (LiFePO4). Instead, we use lithium iron Manganese phosphate (LiFeMnPO4). The doping with yttrium will increase the cells life expectancy and performance. The conceptual design and chemistry of our Li-cells renders them intrinsically safe, this means in case of a problem the cells can not catch fire. By the way, most cell phone or laptop batteries are not intrinsically safe! Lithium cells are almost completely recyclable. And - in contrast to lead batteries - they do not contain any hazardous material. Lab test demonstrates life expectancy In cooperation with the University of Applied Sciences in Ansbach we have tested our LiFeMnPO4 cells under extreme conditions. The lithium cell is discharged to 80% DoD approximately 33 times per day with 1C charge and discharge current. We have exceeded 8000 cycles! The results confirm a very high load capacity and reliability, and verify the superior quality of the cells used for our Joulie+ battery.