We have cars with full of electronic gadgets so they consume significant electricity, even when car is being driven. Almost every week we get no start due to weak battery. I have an external car battery charger (old). It is bulky to setup to charge cars overnight. Also it does not have any detection, so the battery can be continuously overcharged, which will eventually damage the battery (as multiple battery experts tell me). Never learned our lesson as we had 3 quality batteries purchased and replaced - each within 2 years.