HCL-RS 7.6V-6400mAh-120C LiHV 5mm Inboard Hardcase. ROAR APPROVED
Introducing the HCL-RS line of race packs (High Cycle Life - Race Series). These formulations are not the generic cells/packs you can get with different color stickers on them. These are recipes developed for us by an independent factory. While we have recently pushed mAh and C rates for applications like flight packs and speed run packs, the demands of racing are different. These new formulations hold better voltage, sag less under loads seen in off and on road racing by optimizing the IR and mAh per cubic centimeter of the cells.
Please note that in an effort to optimize performance by increasing the cell thickness we had to make our cases thinner so this is resulting in some minor cracking of the cases. We are working with our case supplier to resolve this issue. The cells/pack remains protected against denting which is what the case is designed to do.
LiPo Swell
LiPos perform best when they get warm (not hot). As the chemistry does its thing under load, some of the energy transfers to heat. In the case of LiPo chemistry, this lowers internal resistance slightly and pack performance increases. The downside, and there always is a downside, is that a small amount of gas is produced. This is where LiPo swell comes from, and it’s a constant to all LiPo chemistry. Further, even a high amp charge and high load discharge causes some very small cell expansion.
Some formulations are more or less affected, but it’s always there (up to 15% of EACH cell thickness in some cases). In hardcase applications, we try to leave a small airgap to allow for the natural swell. But when case size is driven by competition rules, we are leaving performance on the table by not maximizing the cell size within the case. We minimize case thickness enough to still meet the stringent requirements, but maximizing the cell may cause a small amount of case roundness when the cells are at their hottest, like after a hard run. This is the trade off to maximize performance.
Keeping cells at storage voltage when not in use further helps to maximizing performance and holding shape.
