Does using two SIM cards in a smartphone drain the battery more? If yes, what does the phone do differently to cause a higher energy consumption?

If take out one SIM card, is it true that the phone still transmit microwaves towards cell towers for this free slot?

Does phone trasmit more EM per unit of time when use two SIM cards?

  • Dual SIM smartphones only have one antenna, so they have to switch between SIM1 and SIM2. If one SIM slot is empty all actions related to that slot are simply. As the phone already scans all cellular towers nearby an empty SIM2 slot should not cause any battery usage. Only if a SIM card is inserted switching between the networks/cell towers should have cause a slightly more battery usage as the time sender/receiver unit is active increases.
    – Robert
    Commented Nov 16, 2022 at 12:06
  • @Robert So we can say in unit of time two sim phone transmit more microwaves toward cell towers?
    – 22flower
    Commented Nov 16, 2022 at 12:09
  • The phone has to keep connection with two towers and if you move around it also have to perform a hand-over to the next tower twice that often, so yes there should be a slightly higher battery consumption.
    – Robert
    Commented Nov 16, 2022 at 12:11


You must log in to answer this question.

Browse other questions tagged .