Review on 🔋 Rezervo Batteryless Jump Starter - Ultracapacitor Technology - Jumpstart Vehicles (RZ-550 (550A)) by Vincent Pavelko

I bought so many ordinary lithium iron starters. They work fine as long as you keep them charged and I've helped quite a few people. A few months ago I offered my jump starter to start the car but it didn't have enough power to get it running. I started looking for better options and came across this device. I just got it a few days ago and tried it on my 2004 Volvo S40 with a battery that needs replacing. When the device was plugged in, it showed 7V. I pressed the start button and after about two minutes the device showed 14V. Went and tried the ignition and the car started without hesitation. I am very impressed! The device is quite solid and well made. It's not exactly cheap, around $100. Remember that these devices require a certain amount of residual charge in the vehicle battery to operate. When the car battery is completely dead, you need another source to charge the jump starter. See attached video.