Tag Archives: does engine running recharge battery

A car engine is started using a battery and the battery is recharged by the alternator whilst driving. The question though is “does the car keep the battery charged when the engine is idle?”. Although I am 38 years old already, I am fairly new to Cars but I recently put this to the test. Just to let you know why, In my first or second year of driving I was parked outside a supermarket. My wife was shopping and I thought it would be a good idea to stream Netflix to my phone during the wait. I connected my phone to the in car charger but did not fire up the engine. I know women like to shop a lot but it must have only been a 45 minute to one hour wait. When my wife got out and we were ready to go home, I tried to start the engine. Lifeless, called the breakdown service out and it was nothing but a flat battery. That’s when I realized that despite car batteries being extremely large, they don’t last long without the alternator charging them. Another time we had a semi flat battery, I researched extensively to see the best procedure for getting the battery to full strength. The common answer was to drive the car at high revs on a main road. Continue reading →