Battery life - Garmin Drive 51 compared to Garmin Zumo 390lm

OK...bought a Garmin Drive 51 for the car but sent it back as the battery was not holding a charge ( even when switched off ) for two weeks. So, got the replacement two weeks ago and charged it up ( and downloaded all maps etc )...but came to use it today ( switched off for two weeks ) and the battery was showing in the red !
My Garmin 390LM stays charged forever in comparison !!
Just wondering if I am over reacting to a battery life before I send it back again

Also, when I went to use it and selected 'address' so I could put in a new postcode.. just got the display saying "Map data is not available" WTF ! It can show me the way home and also displays a map when I select maps etc.

Is this one goosed as well?

Well sorted it out myself.....reply from garmin:-

Thank you for contacting Garmin.

I am sorry to hear you are not happy with the battery for the device.

The battery for these devices when fully charged and running on own battery and not connected is up to one hour where as your Nuvi 1410 is up to three hours. Our devices will need to be plugged in at all times when in use in the car.

Kind regards,

Garmin Europe

P.S. Downloaded an update and all seem's to be working correctly.

Anyone want to buy it ? £65.00 delivered...I'll maybe try a Tom Tom next