There are a few parameters, which might result in better battery life, so I copied them from Softbank ROM to 1.21 WWE, rebuilt and battery life went back to normal. Just in case, here are those parameters:

ro.ril.enable.a52=0
ro.ril.enable.a53=1
ro.ril.fast.dormancy.timeout=3
ro.ril.enable.sbm.feature=1

Still, no idea what do they mean, especially “enable.sbm.feature” (SBM probably means SoftBank Mobile).