Charger Question

You didn't mention the charger voltage but I assume it's also 5V.

It's the current (in amps) that matters. Your charger and the appliance appear to match at 2A so you're good to go.

The bulb wattage and the battery capacity are relevant if you were trying to work out how long the appliance will run with fully charged batteries but it's only the amps that matter (assuming the voltage is the same) when figuring out if the charger is compatible.

That charger has the same amp rating as what the lamp is looking for so it's fine.

It may be possible to use a charger with a higher amp rating, it depends on whether the lamp can negotiate the charge it will take. For example, if the lamp supports a feature called 'Power Delivery', you could use any charger with the same feature and the two devices would negotiate a charging current of 2A, even though the charger might be capable of delivering a much higher current.

Without knowing anything about the lamp, I would recommend you stick with chargers rated at 2A or less. A 1A or 1.5A charger will also be safe to use, they would just take longer to achieve a full charge.