Have never come up in my mind even. Don´t know how much the GPS take electric, but it can´t take much. Have the GPS always connected directly to the battery. Forgott few times on my motorcycles to turn of the GPS at nighttime and there was no problem to start the bike at morning. Zoomer has a good generatorpower(210w) for a moped. Used also gripheaters fairly frequency on my trip(2x15w).....no problems.