How can I charge an HP EliteBook G3 without its original charger?

This model normally needs an HP-compatible barrel-plug adapter, usually around 65W and 19.5V. A used charger from an electronics-repair shop, recycling center, pawn shop, or local computer store may be inexpensive, and some places might let you borrow one briefly. Don’t connect a random power supply unless the voltage, plug size, polarity, and wattage all match.

If you find a USB-C-capable version or a later EliteBook model, it would need a proper USB-C Power Delivery charger and cable with enough output, typically at least 65W. But for an EliteBook G3, the safest practical solution is a matching replacement barrel charger, preferably borrowed or bought used.

USB-C charging won’t work on most HP EliteBook G3 models because their USB-C port is for data and accessories rather than USB Power Delivery. A USB-C phone charger or your desktop’s 200W power supply also can’t charge the laptop directly; the computer’s internal power supply isn’t a compatible laptop charger.