I wanted to try using an external powerbank to overcome disposing of hundreds of AA batteries. I have tried a 5V powerbank supplied by RS (link at bottom of message). This is a reasonably compact size (101*66*16) and so far has powered an Audiomoth for multiple nights of recording without any power down/sleep problems. The only slight issue is some interference on the recordings, visible as faint lines every 500Hz (sample rate = 32kHz, medium gain).

I have tried three different USB cables and all show the same effect. I've confirmed this is not due to external soruces (lines are absent when using 3 AA batteries in same recording location).

This is probably bearable for my uses but does anyone know:

1. whether it is possible to overcome this;

2. whether its possible to be confident that these artefacts won't be any worse if I bulk buy more of the same powerbanks.

thanks for help

Simon

Link to RS power bank

https://uk.rs-online.com/web/p/products/7757508/?grossPrice=Y&cm_mmc=UK-PLA-DS3A-_-google-_-CSS_UK_EN_Batteries-_-Rechargeable_Batteries%7CPower_Banks-_-PRODUCT_GROUP&matchtype=&pla-473297947647&gclid=EAIaIQobChMIyqaakeqB4wIVY7XtCh0tCw-0EAYYASABEgIUYfD_BwE&gclsrc=aw.ds