What Do Those 8 Pin Letters Stand For On A DeWalt Battery?

Ever noticed that row of small metal contacts when sliding a DeWalt battery into a tool or charger? Or tried troubleshooting some of the most common problems with DeWalt batteries yourself? What do all those letters and numbers mean? Plenty of independent teardowns and analyses from hobbyists have attempted to tell us why those symbols are there, but we spoke to Stanley Black & Decker directly to get a definitive answer. 

The DeWalt brand owner confirmed that each marking is there for reference, with each letter and number corresponding to a different battery terminal. "TH" stands for Thermistor, which electronically monitors the battery temperature. It keeps the battery and the tool safe if things get too hot or too cold. "ID" stands for Identification, and it's the part that tells the DeWalt tools and chargers they're hooked up to a compatible battery. C1 through C4 represent the cell voltage nodes, and B+/B- mark the power terminals.

The folks doing independent teardowns do a good job explaining how each part of the terminal works. For instance, an explainer by Redditor @Tool_Scientist elaborates on the ID terminal, saying it uses a resistive value tied to ground to help the charger or tool recognize the pack type and capacity (and to make sure the battery works as intended for both DeWalt and Klein power tools). Other hobbyists like Russell Graves explain the C1 through C4 pins help the charger balance the cells during charging. That, in turn, improves the battery's runtime.

Of course, it needs to be said that tinkering with the inner workings of DeWalt (or any power tool brand) batteries is extremely dangerous. What's more, it'll void your warranty because you're tampering with the device. The Stanley Black & Decker rep we spoke to made it clear: "The terminals are not to be engaged by the end user by any other means. Please reference the manual for proper battery use."