Sodaq Onev2/Sodaq Base - not charging

Hi

I have now purchased 3 bases and 3 power packs but I have not managed to get them working yet with the sodaq one v2

can you tell me how I charge the battery please. I have plugged the USB lead into the sodaq one and the lithium power packs into base. I have left them overnight but I can’t run the sodaq using the battery. what am I doing wrong?

please can you advise

thanks
Steve