Agree with Searush, and remember if any GPS is left switched off for more that 24 consequtive weeks it will loose it's almanac and may need up to 45 minutes to get a cold fix on 1st power up. This is common after winter storage. Some models may manage this in 15mins.

Also if a GPS is moved a significant distance (eg 100miles) when switched off it may take an extra few minutes to get a fix in a new location.