Battery/ power bank for USB sensor activated light

[RJRock]

Battery/ power bank for USB sensor activated light

Looking for a power bank of at least 10,000 mAh with no auto off function. 5v 1a output.

Problem: We have a lovely sink with a movement sensor that lights up the bathroom. It’s great for night time visits to bathroom and looks great.

The power is provided by a small power bank of 4,000 mAh that can with the sink (no brand name on it - white one in pictures) It roughly powers down in about 3 days depending obviously on amount of activation.

I bought a 20,000 mAh power bank (black one in pictures) but unfortunately after a short period of inactivity it auto powers down so needs to be switched on by pressing a button on the battery- defeating the whole point of a sensor activated light.

There is a hack involving pushing the button for a few seconds to keep the power bank live for longer but it still powers down eventually when no current drawn is sensed.

The sink is in our Airbnb and we regularly get feedback saying the sink light stopped working during our visit (battery goes flat basically).

I’ve searched on the internet a long time without finding a 1a 5v power bank without a power down feature and also bought 2 that turned out to have auto power down feature.

Any help appreciated.

 

[cdbe]

Have you tried plugging the bigger one into the existing? It might convince it to stay on. Bit strange generally because I would have thought the sensor would draw a tiny bit of power all the time.

 

[RandomGrinch]

There are power bank "keep-alive" circuits available - either to DIY, or to buy...

Power Bank Keep-Alive based on 555 Timer – Eplop Electronics

store.eplop.co.uk

They are usually based around a 555 timer IC. As the power banks go into a standby mode when a small current is drawn, the timer provides a higher current pulse every so often.
This is enough to stop the power bank from entering standby, but shouldn't deplete the battery too quickly.

To DIY, the circuit may look something like this..

 

[RJRock]

Thanks that’s really good to know

 

[RJRock]

Have you tried plugging the bigger one into the existing? It might convince it to stay on. Bit strange generally because I would have thought the sensor would draw a tiny bit of power all the time.

Awsome

 

[RJRock]

This worked a treat- after charging the old battery it’s continued to stay live. As I bought 2 20,000 mAh power banks it’s an easy swap and I’m guessing it’ll last for weeks