No idea on the maps and also hopefully someone can help properly but with the Battery, a lot of cars use a radio code so when the stereo is removed (disconnected from the battery, so removing the battery does the same thing) you have to enter the security code for it to work when reconnected. Its a bit of a pain if you don't have the code as dealers tend to charge a fair bit for a new code.
If you can get the thing out there will be a code on it somewhere. Have a Google and you can find all the codes to reset after battery swap. Did this on my focus a while ago
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