# Non rechargable backup battery **URL:** \ **Category:** General Electronics\ **Created:** [October 1, 2023, 7:48pm UTC](https://forum.arduino.cc/t/non-rechargable-backup-battery/1174097 "2023-10-01T19:48:10Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![arpa123](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/arpa123/32/1098836_2.png) [@arpa123](https://forum.arduino.cc/u/arpa123)\ **Post date:** [October 1, 2023, 7:48pm UTC](https://forum.arduino.cc/t/non-rechargable-backup-battery/1174097/1 "2023-10-01T19:48:11Z")
![battery](https://europe1.discourse-cdn.com/arduino/original/4X/d/4/a/d4a12b8fa30b5340eedffb171a252d132d0d674b.png) If I'm using an Arduino or an ESP8266 NodeMCU board and have it connected to a power supply, how can I set up a backup battery? Let's consider a scenario: the board has been running on the power supply for one year, and then a power outage occurs. In this situation, I want the board to switch to a backup battery, not necessarily for an extended period, but just long enough to send a notification indicating a power outage. Please note that the battery is not rechargeable and is meant to be in place solely as a fail-safe measure in case of power failure. What components or methods can I use to accomplish this? the point is while battery not used, not to discharge it ---
**Author:** ![ShermanP](https://avatars.discourse-cdn.com/v4/letter/s/b19c9b/32.png) [@ShermanP](https://forum.arduino.cc/u/ShermanP)\ **Post date:** [October 1, 2023, 9:24pm UTC](https://forum.arduino.cc/t/non-rechargable-backup-battery/1174097/2 "2023-10-01T21:24:43Z")
What is the voltage of your power supply, and what battery will you be using? ---
**Author:** ![Paul\_KD7HB](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/paul_kd7hb/32/1127958_2.png) [@Paul\_KD7HB](https://forum.arduino.cc/u/Paul_KD7HB)\ **Post date:** [October 1, 2023, 10:30pm UTC](https://forum.arduino.cc/t/non-rechargable-backup-battery/1174097/3 "2023-10-01T22:30:02Z")
> [@arpa123](#): > > the point is while battery not used, not to discharge it In the real universe, ALL batteries are chemical devices and will self-discharge. Even atomic backup devices have a limited lifetime. ---
**Author:** ![LarryD](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/larryd/32/215550_2.png) [@LarryD](https://forum.arduino.cc/u/LarryD)\ **Post date:** [October 1, 2023, 10:37pm UTC](https://forum.arduino.cc/t/non-rechargable-backup-battery/1174097/4 "2023-10-01T22:37:12Z")
Feed the power supply and battery to two common cathode Schottky diodes. Your power supply needs to be greater than the battery voltage. Feed the cathode output voltage to a Boost/Buck converter set to the controller supply voltage. ---
**Author:** ![alto777](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/alto777/32/317385_2.png) [@alto777](https://forum.arduino.cc/u/alto777)\ **Post date:** [October 1, 2023, 10:43pm UTC](https://forum.arduino.cc/t/non-rechargable-backup-battery/1174097/5 "2023-10-01T22:43:10Z")
> [@arpa123](#): > > just long enough to send a notification is quite possible with a largish capacitor and a few other components. The technique is used often to afford an opportunity to write to EEPROM. Google and or see [https://forum.arduino.cc/t/saving-to-eeprom-on-power-out/77176/2](https://forum.arduino.cc/t/saving-to-eeprom-on-power-out/77176/2) a7 ---
**Author:** ![traisjames](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/traisjames/32/1098976_2.png) [@traisjames](https://forum.arduino.cc/u/traisjames)\ **Post date:** [October 2, 2023, 5:37am UTC](https://forum.arduino.cc/t/non-rechargable-backup-battery/1174097/6 "2023-10-02T05:37:58Z")
> [@LarryD](#): > > Feed the power supply and battery to two common cathode Schottky diodes. Why Schottky diodes as opposed to regular? As long as both the external supply is a slightly higher voltage won't the Arduino just run on that, but if it drops low or out the batteries take over? ---
**Author:** ![jhaine](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/jhaine/32/707424_2.png) [@jhaine](https://forum.arduino.cc/u/jhaine)\ **Post date:** [October 2, 2023, 6:05am UTC](https://forum.arduino.cc/t/non-rechargable-backup-battery/1174097/7 "2023-10-02T06:05:19Z")
They have lower forward voltage drop. ---
**Author:** ![LarryD](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/larryd/32/215550_2.png) [@LarryD](https://forum.arduino.cc/u/LarryD)\ **Post date:** [October 2, 2023, 6:16am UTC](https://forum.arduino.cc/t/non-rechargable-backup-battery/1174097/8 "2023-10-02T06:16:04Z")
![2023-10-02_00-27-07](https://europe1.discourse-cdn.com/arduino/original/4X/4/3/1/431caef12c2096e0a54e22f56cfdff9813e96f33.jpeg) Not sure what batteries you are using. Here is one way to connect things. Schottky diodes have a Vf of about .2 or .3V where Silicon is .7 to .8V - When the UNO is connected to the PC via USB, disconnect the Boost/Buck converter. ---
**Author:** ![system](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/system/32/1140315_2.png) [@system](https://forum.arduino.cc/u/system)\ **Post date:** [March 30, 2024, 6:16am UTC](https://forum.arduino.cc/t/non-rechargable-backup-battery/1174097/9 "2024-03-30T06:16:34Z")
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