My new to me XS with front and rear sensors as developed a fault.

The battary was changed last week by a specialist and since then when starting i hear a low extended tone. If i select reverse the front PD light on the dash flashes but no beeping from front or rear sensors.

I've read through the thread on parking sensors but couldn't find anyone with the same problem.

The cars going back to the indipendant specialist this week with a problem with the battary light staying on, on the dash, does anyone think it's linked to the battary change?

Thanks in advance