These camera’s are pretty old, is it the batteries are failing? If that is normal when they get older, can the battery be replaced. At least two of them are doing this..
thanks, Pete
Old age slows everything down. 
I have four battery powered WCO v1 cams that will be 6 years old on 4 November. They will all charge up to 100% as shown on the app but they don’t retain their charge as long as they used to. I have always charged them when the got to between 38-40% since I’ve had them and still do. The cams that record the most events will now go from full charge down to 40% in about 4-5 weeks. I have them set at no cooldown period and the max length for each event set at 1 minute. There are users that have taken the cameras apart in attempt to replace the batteries but most have found that finding the correct replacements are next to imposssible. Besides that once you take it apart your chances of failure increase. Be nice to the old folk cams and let them have a natural demise.
I have tried three different chargers and two of the cameras only get to 60 % even though they still work fine.
You can charge them from the base station USB Port on the left side. Never tried it but it is available,