ADC causing current increase during deep sleep

[beelzmon]

Currently, some basic code sending data over LoRa and then going into deep sleep is functional, and during deep sleep has about 28 u-amps current. See below, where bytes would be replaced by data to be sent.

lora = LoRa(mode=LoRa.LORAWAN , region=LoRa.AU915, adr = True )
lora.join(activation=LoRa.OTAA, auth=(app_eui, app_key), timeout=0)
for index in (list(range(0,8))+list(range(16,65))+list(range(66,72))): 
  lora.remove_channel(index)
s = socket.socket(socket.AF_LORA, socket.SOCK_RAW)
s.setblocking(False)
while True:
  s.send(bytes)
  machine.deepsleep(60000)

However, addition of the following code increases this current to 51 u-amps. This code just reads the battery voltage via ADC. See below the new code:

lora = LoRa(mode=LoRa.LORAWAN , region=LoRa.AU915, adr = True )
lora.join(activation=LoRa.OTAA, auth=(app_eui, app_key), timeout=0)
for index in (list(range(0,8))+list(range(16,65))+list(range(66,72))): 
  lora.remove_channel(index)
adc = machine.ADC()
adc.init(bits=10)
adc.vref_to_pin('P22')
adc.vref(1100)
Channel  = adc.channel(pin='P13', attn = machine.ADC.ATTN_0DB)
Current_Battery_Reading= Channel.voltage()
Channel.deinit()
adc.deinit()
s = socket.socket(socket.AF_LORA, socket.SOCK_RAW)
s.setblocking(False)
while True:
  s.send(bytes)
  machine.deepsleep(60000)

It looks to me that i disabled the ADC after use, but the current is still higher than without it. Is there something i am missing in order to have the deepsleep current remain at 28 u-amps, and not increase to 51 u-amps with this new code.

[beelzmon]

SOLVED: The line adc.vref_to_pin('P22') was causing this. Should only be run for calibration with a multimeter for the vref value once, is the current conclusion.