I brought my OM-4 in twice complaining of battery drain and they never replaced my board. Left me a note instead telling me my batteries were dead.

In the long run, I grew experienced in the matter and only missed a few shots due to dead batteries. The secret? Use cheapest Alkaline A-76 and carry no fewer than 6 spares. Even on week-long backpacking trips, the camera never went through all 6.

When it locks up dead battery... Just spin the shutter to the manual 60 or B and fire a shot. Change battery and be back in business with no drama.

I'll second what E. von Hoegh said... get a spotmeter. Get one with a holster for your belt. Then you will have spotmetering for every camera you own - and you never have to use a built-in camera meter again.