Did one more test - desoldered copletly GPS (also power lines) and tried few times to read log with and without batteries. Results:
for a few times with battery attached i have this reading:
23:18:38 102 [Power] Battery: usbPower=0, isCharging=0, batMv=2281, batPct=0
without battery:
??:??:?? 42 [Power] Battery: usbPower=0, isCharging=0, batMv=2449, batPct=0
or
??:??:?? 42 [Power] Battery: usbPower=0, isCharging=0, batMv=2507, batPct=0
but also
??:??:?? 9 [RadioIf] (bw=125, sf=12, cr=4/8) packet symLen=32 ms, payloadSize=33, time 3153 ms
??:??:?? 9 [RadioIf] Lora RX (id=0x4abb12e9 Fr0x4c To0xff, WantAck0, HopLim2 Ch0xb1 encrypted
rxSNR=12.25)
??:??:?? 9 [RadioIf] AirTime - Packet received : 3153ms
??:??:?? 9 [Router] Found existing packet record for fr=0xc4a70a4c,to=0xffffffff,id=0x4abb12e9
??:??:?? 9 [Router] Ignoring incoming msg, because we've already seen it (id=0x4abb12e9 Fr0x4c
To0xff, WantAck0, HopLim2 Ch0xb1 encrypted rxSNR=12.25)
??:??:?? 9 [Router] Incoming message was filtered 0xc4a70a4c
??:??:?? 9 [RadioIf] Starting low level send (id=0x4abb12e9 Fr0x4c To0xff, WantAck0, HopLim1
Ch0xb1 encrypted rxSNR=9.75 priority=64)
??:??:?? 12 [RadioIf] Completed sending (id=0x4abb12e9 Fr0x4c To0xff, WantAck0, HopLim1
Ch0xb1 encrypted rxSNR=9.75 priority=64)
??:??:?? 22 [Power] Battery: usbPower=0, isCharging=0, batMv=2500, batPct=0
??:??:?? 22 [PowerFSM] Loss of power in Powered
Transition powerFSM transition=power disconnected, from=POWER to=ON
??:??:?? 22 [Screen] Screen: Unpowered...
??:??:?? 32 [NodeInfoPlugin] Sending our nodeinfo to mesh (wantReplies=1)
??:??:?? 32 [NodeInfoPlugin] sending owner !d1dc6dc4/Ewelina/Ewl
??:??:?? 32 [NodeInfoPlugin] Update DB node 0xd1dc6dc4, rx_time=0
??:??:?? 32 [NodeInfoPlugin] handleReceived (id=0x0dca25f0 Fr0xc4 To0xff, WantAck0, HopLim3
Ch0x0 Portnum=4 WANTRESP priority=10)
??:??:?? 32 [NodeInfoPlugin] Plugin nodeinfo wantsPacket=1
??:??:?? 32 [NodeInfoPlugin] Received nodeinfo from=0xd1dc6dc4, id=0xdca25f0, portnum=4,
payloadlen=35
??:??:?? 32 [NodeInfoPlugin] old user !d1dc6dc4/Ewelina/Ewl
??:??:?? 32 [NodeInfoPlugin] updating changed=0 user !d1dc6dc4/Ewelina/Ewl
??:??:?? 32 [NodeInfoPlugin] Plugin nodeinfo considered
??:??:?? 32 [NodeInfoPlugin] Plugin routing wantsPacket=1
??:??:?? 32 [NodeInfoPlugin] Received routing from=0xd1dc6dc4, id=0xdca25f0, portnum=4,
payloadlen=35
??:??:?? 32 [NodeInfoPlugin] Routing sniffing (id=0x0dca25f0 Fr0xc4 To0xff, WantAck0, HopLim3
Ch0x0 Portnum=4 WANTRESP priority=10)
??:??:?? 32 [NodeInfoPlugin] FIXME-update-db Sniffing packet
??:??:?? 32 [NodeInfoPlugin] Delivering rx packet (id=0x0dca25f0 Fr0xc4 To0xff, WantAck0,
HopLim3 Ch0x0 Portnum=4 WANTRESP priority=10)
??:??:?? 32 [NodeInfoPlugin] Forwarding to phone (id=0x0dca25f0 Fr0xc4 To0xff, WantAck0,
HopLim3 Ch0x0 Portnum=4 WANTRESP priority=10)
??:??:?? 32 [NodeInfoPlugin] Update DB node 0xd1dc6dc4, rx_time=0
??:??:?? 32 [NodeInfoPlugin] Plugin routing considered
??:??:?? 32 [NodeInfoPlugin] Adding packet record (id=0x0dca25f0 Fr0xc4 To0xff, WantAck0,
HopLim3 Ch0x0 Portnum=4 WANTRESP priority=10)
??:??:?? 32 [NodeInfoPlugin] Expanding short PSK #1
??:??:?? 32 [NodeInfoPlugin] Installing AES128 key!
??:??:?? 32 [NodeInfoPlugin] enqueuing for send (id=0x0dca25f0 Fr0xc4 To0xff, WantAck0,
HopLim3 Ch0xb1 encrypted priority=10)
??:??:?? 32 [NodeInfoPlugin] (bw=125, sf=12, cr=4/8) packet symLen=32 ms, payloadSize=57, time
4431 ms
??:??:?? 32 [NodeInfoPlugin] txGood=1,rxGood=2,rxBad=0
??:??:?? 32 [NodeInfoPlugin] AirTime - Packet transmitted : 4431ms
??:??:?? 32 [Screen] Screen: Joined: Ewelina
??:??:?? 33 [RadioIf] Starting low level send (id=0x0dca25f0 Fr0xc4 To0xff, WantAck0, HopLim3
Ch0xb1 encrypted priority=10)
??:??:?? 38 [RadioIf] Completed sending (id=0x0dca25f0 Fr0xc4 To0xff, WantAck0, HopLim3
Ch0xb1 encrypted priority=10)
??:??:?? 42 [Power] Battery: usbPower=0, isCharging=0, batMv=2217, batPct=0
Transition powerFSM transition=LowBat, from=ON to=SDS
??:??:?? 42 [Power] Entering deep sleep for 31536000 seconds
??:??:?? 42 [Power] Setting bluetooth enable=0
??:??:?? 42 [Power] advertise complete; reason=29error enabling advertisement; rc=30
??:??:?? 42 [Power] Done shutting down bluetooth
Shutdown BT: 222816 heap size
??:??:?? 42 [Power] GPS prepare sleep!
??:??:?? 42 [Power] GPS deep sleep!
??:??:?? 42 [Power] WANT GPS=0
??:??:?? 42 [Power] Turning off screen
??:??:?? 42 [Power] Saving /prefs/db.proto
??:??:?? 43 [Power] Saving /prefs/radio.proto
??:??:?? 43 [Power] Saving /prefs/channels.proto
??:??:?? 43 [Power] Setting GPS power=0