JST-PH
What people call it
PH, "JST battery connector," "LiPo connector," "2-pin JST," battery pigtail.
What it actually is
The genuine JST PH series: 2.0 mm-pitch wire-to-board family, rated 2 A AC/DC (AWG #24) / 100 V per the official JST datasheet, 2–16 circuits, wire range AWG #32–24.1 "JST battery connector" is not a complete description — PH is just the series most often behind that phrase on single-cell packs.
Where it shows up
Small 1S LiPo battery pigtails, dev-board battery ports (many Adafruit-style boards), small sensors, and compact internal harnesses. PH is also the connector behind Adafruit's plain-STEMMA ports (4-pin I2C, 3-pin analog/digital/PWM)2 — not to be confused with the smaller 1.0 mm STEMMA QT, which lives on the SH/Qwiic/STEMMA QT page.
How to identify it
2.0 mm pitch (measure it — visually near-identical to XH's 2.5 mm in photos), low-profile white housing, friction-fit shroud. Two-position PH is the archetypal small battery pigtail; don't confuse it with the slightly larger XH or with RCY, the red 2.5 mm wire-to-wire battery pair.
ID marks: 2.0 mm pitch, low shroud, friction fit — visibly smaller than XH.
What to buy
Pre-crimped PH leads are the sane default — the contacts are tiny and hand-crimping them is genuinely hard (crimping). Otherwise: housing + PH contacts + board header as separate genuine line items (buying mating parts).
PH-style battery leads are not universally wired the same way across boards and battery vendors. Batteries routinely arrive with the pigtail reversed relative to your board's expectation, and plugging a reversed pack into a dev board is a classic dead-board story. Verify polarity against the board silkscreen/documentation — never against wire color — every time, every new battery.
Common traps
- Treating "JST battery connector" as a spec — it names nothing.
- Current wishful thinking. The 2 A headline is a genuine-part, gauge-dependent figure — not a promise for the clone pigtail on a marketplace pack, and not sized for motors or heaters (power vs signal). Verify the exact part/wire/datasheet before drawing real current.
- Forcing PH into XH (or vice versa) — the 0.5 mm pitch difference means damage, not compatibility.
- No latch, no sealing — protected internal use.
Source status
Pitch, type, and headline ratings are sourced to the official JST PH datasheet;1 clone parts are not covered. Polarity conventions are per-vendor and inherently unsourceable — that's the trap. See Hobby Source Notes.
When to move to the engineering track
Battery interfaces that matter (capacity, current, or consequences), anything leaving the bench, or harnesses others build — When Hobby Connectors Are Not Enough, and for the energized-interface discipline, the high-current DC path.