We purchased the faucet in December, 2016, with only the battery pack and had it professionally installed.  The wires from the battery pack are poorly insulated and had to be re-routed to ensure the faucet worked as intended.  Because we use our faucet frequently and have to replace batteries every 3-6 months, we purchased the plug-in adapter and installed it according to the instructions.  However, the battery pack is still evidently needs to be charged because the faucet fails to work when the battery pack is low -- as indicated by the flashing LED at the faucet base -- even when the a/c adapter is in use.  What's the point of the a/c adapter?