Just put the doorbell on for its 2nd charge since buying it and 24 hours later only on 25%. When I put it on charge it had 40% 
That’s weird, it shouldn’t take that long to charge it an hour tops if it was at 10%…if you had only 40% on it it should have topped it off already with in 35 minutes.
Try a different charger or cable.
Does the app show that it’s charging? The battery icon bars sequentially flashing.