Imagine looking at the battery’s connector slot. The terminals run along the top edge:
[ B- ] [ T2 ] [ T1 ] [ ID ] [ B+ ]
| | | | |
Large Small Small Small Large
Slot Pin Pin Pin Slot
(Left) (Right)
Orientation tip: When the battery is standing on its base (the side with the fuel gauge button), the B- terminal is on the far left, and B+ is on the far right. Hart 20v Battery Pinout Diagram
| Brand | Works with Hart? | Notes | |-------|----------------|-------| | Ryobi 18V | ❌ No (mechanically) | Pins are identical electrically, but the slide rail shape is different. | | Ridgid 18V | ❌ No | Different terminal spacing. | | Milwaukee M18 | ❌ No | Completely different. | | Hart 20V tools | ✅ Yes | All Hart tools and chargers. | Imagine looking at the battery’s connector slot
Warning: Do not force a Hart battery into a Ryobi tool or vice versa. Even if pins match, the plastic housing will damage either the tool or battery. Orientation tip: When the battery is standing on
HART is a brand collaboration between Walmart and Techtronic Industries (TTI), the same parent company that makes Ryobi, Ridgid, and Milwaukee tools. However, HART batteries are not identical to Ryobi or Milwaukee. They use a unique BMS that authenticates with the charger.
Most HART 20V battery packs (models like HGB20, HGB40, HGB60, HGB80) have 4 to 5 metal terminals on the top mounting rail. The common mistake is assuming only the large outer slots (positive and negative) matter. In reality, the inner smaller pins are the brains of the operation.