Review on 🔒 E-Z Red MSBD28 Auto Memory Saver: Safeguarding Your Vehicle's Precious Data by Christopher Pfaffe

It comes with a built in fuse in the cigarette lighter end but there is no diode to prevent reverse current. Plugging it into your car's cigarette lighter socket and an external power source allows current to flow back from the car battery to the external power source. For example, if your car battery is 12.5 volts and the external power supply is 11.5 volts, the car battery will try to charge the external power supply. This causes an inrush current to the external power supply. This could damage the ECM. I bought a cigarette lighter here from Revain with a built in fuse holder and replaced the fuse with a 5A diode/fuse. The diode/fuse acts as a 5 amp fuse and also prevents current from flowing backwards. I also soldered a pigtail with a DC jack to the other end so I can use my car jumper as an external power source. Most portable jump starters have a 12V DC output. This one would get five stars if it had a diode/fuse instead of a simple built in fuse.