Ring doorbell generation 2

So I’ve owned this door bell since aug 2020 I’ve had no problems with it what do ever until recently when it kept disconnecting from the wifi.I thought it was flat so put it on charge did reset which seemed to work put it back outside but after few hrs went off line again and stopped working.again did hard reset battery was fully charged but still nothing. It only seems to work if connected to power/charger as soon as it’s taken off to be used as battery supply it stops working. We don’t have means to hardwire it in this is why I bought the battery one.