Can i connect 2 relays of the same specs and same coil voltage of 12 in series ie 86 of one relay to positive battery, it's 85 joined to 86 of the other relay and obviously the end 85 to ground??

1 Answer 1


Both relays need 12V to reliably operate the coil, in series they will only get 6V.

So, no this is not a good idea.

The best is to connect them in parallel and they will operate at the same time.

  • Yes, I apply 6v to one relay by using voltage regulator. The relay works. Actually, I want voltage drop on each relays be about 6 vol and current 0.04 amps. Is there any extra diode I should connect in between the 2 relays so that reverse current will not flow???
    – Thang Tons
    Jun 12, 2019 at 6:14
  • Why try to operate a 12V relay with 6V? use 12V or get relays with 6V coils... you may end up with an unreliable performance...
    – Solar Mike
    Jun 12, 2019 at 6:28
  • Why would it only get 6V? What is reducing it by 1/2? The power going through is still 12V. What am I missing, Mike? Jun 12, 2019 at 11:00
  • My goal is....I want those 2 relays to control one remote door lock module and one window closer module at the same time by cutting power supplies to each modules whenever any door is opened. The trouble is when only 1 relay is used, a significant 0.12 amps is drawn. Then, for all 4 doors, .012x4. So, by dropping to 6 volt each, I could easily obtained .04 amps with extra relay connected in series. Hope this is clear. Awaiting more suggestions.
    – Thang Tons
    Jun 12, 2019 at 12:39
  • @Pᴀᴜʟsᴛᴇʀ2 If you wire the 2 coils in series the voltage will be shared equally between the 2 coils, so each will only see 6 volts and since the total resistance is doubled, the current will be halved. Wiring them in parallel will put 12v across both coils and they will get the full current they require to energize them.
    – HandyHowie
    Jun 12, 2019 at 13:19

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