Which battery should i get?

[clawnik]

i just bought a canonet QL19 on ebay everything works fine but i need to buy a battery. which battery works best for it?

 

[bgb]

http://www.rangefinder-cameras.com/Canon-Canonet-QL19-New-Model-1971-Rangefinder-cameras.htm

"I use readily available LR44W 1.55v alkaline button cells. The correct battery recommended in the manual is a 1.3v mercury cell M20. This is the same as a Mallory PX625. These mercury batteries are no longer available. The LR44W alkaline cells I use seem to work fine even though the voltage out put is different to mercury cells as they discharge. There is a fair bit of leeway when developing modern negative films so the slight voltage difference doesn't seem to matter. "