battery draining by plughing in the GPS

[varunj]

i was using a GPS when traveling to Oman and slowly i started noticing that the battery is getting low when all the lights started getting dimmer

so i unplugged the GPS and lights were brighter which indicated that the batter was doing good so i reconnected the GPS and the same thing happened again.

any reason to this situation

[fransisaudi]

Do you see any red color battery icon in dash?

If yes that means battery is getting weak or not charging enough. If no icon and car starts perfectly everyday, then i wont bother much unless the battery fails. It may be that battery is getting weak or not fully charge SOMETIMES. And once it charges good it will be fine.