Battery's going flat in Garmin GPS 64s

Only had this 18mths - 2 yrs  roughly ,yet went to turn it on the other day ,wouldn't power up ,battery's flat , 2nd  or 3rd lot now ,probably 8-9 mths on this last lot ,there Alkaline battery's ,i'm presuming now that there must be a small drain active ??? to keep the memory alive ?? reread the instructions ,hasn't really helped espically when it comes to storage ! If I take the battery's out when storing it , will it loose its memory ,and I 'll loose what's on there  I see there are other battery options with it ,am I better off going Lithium ???

Hugh, We use the Garmin Rinos and recharge the batteries monthly when not in use. During summer months or long periods away from use I remove the batteries, data is not lost.

Here is a reply received when I googled your model.

When you do not plan to use the device for several months, remove the batteries. Stored data is NOT lost when batteries are removed.

https://www.google.com/search?safe=active&ei=KzBmXZbJCIa5rQGv5IXoBg&q=Is+memory+lost+when+batteries+are+removed+Garmin+GPS+64s&oq=Is+memory+lost+when+batteries+are+removed+Garmin+GPS+64s&gs_l=psy-ab.12...5148.28216..30446...4.2..0.268.9458.0j8j36......0....1..gws-wiz.......0i71j35i304i39j0i13j0i13i10j0i8i7i30j33i10.o0vzcPZ9rlo&ved=0ahUKEwjWivmjiKXkAhWGXCsKHS9yAW0Q4dUDCAo

Great answer Nightjar. cheers Pete.

Well that was simple thanks Nightjar ,good ol Google to the rescue again