F.e. here:
http://www.smallbattery.company.org.uk/sbc_a220.htm (UK)
http://batteribyen.dk/varta_v74___a220___eveready_504___rayovac_220___blr154__15v_-p-3105.html (Denmark)
And for the search machines and other surfers;
The battery for the Beomaster (1900), 1900-2, 2400, 2400-2, 6000 (quad version) and Beovision 6000 series ultrasonic remote control commander is a 15V cell.
Let's also put these equivalents in:
Eveready 504, Duracell M504, Mallory M504, MN154, B154, BLR154, Exide DH554, Rayovac 220, BA332/U, Panasonic W10E, Burgess Y10, GP 220A, Varta 74, Pertrix 74, V74PX, Kodak KA74, W10, TR149, NEDA 220, ANSI 220, IEC 10F15.
Martin