12v Charger Won't Charge or Recognize a Battery? [Easy Fix in Under 5 minutes]

This video covers why a 12 volt battery charger won't charge a battery and what you can do to fix it.

00:00 Intro
00:13 Why a Charger Won't Recognize a Battery
01:38 How to Get a Charger to Recognize a Battery
03:00 Batteries That Can't Be Recovered

Applies to car, boat (marine), lawn tractor batteries and more. Anything that's 12 volts.

Modern smart chargers are equipped with safety features that require a battery to have a minimum voltage (usually around 9.5) in order to recognize that they are indeed hooked up to a battery before they will proceed with charging.

If your battery is below that minimum voltage, you'll get an error code and the charger will not function.

To overcome this, you will need to give the dead battery a surface charge with a set of jumper cables and a running vehicle.

Go ahead and hook the cables up in the appropriate order and wait for 3-5 minutes.

Unhook the cables in the reverse order and immediately put the battery charger back on the battery.

The charger will now recognize that it is hooked up to a battery because of the surface charge and will engage the charging process.