I have a Viking 450 amp cordless and rechargeable jump box. It is a harbor freight special, but it cost 80 bucks. It will jump anything from a lawn mower to a twin battery Cummins dodge, any of our tractors to a 6 batteries, 12 volt Kenworth. I’ve had it about 3 years now and it rides around in my Jeep and I use it regularly. It’s small, about the size of a average novel, comes in an enclosed case with several cords to charge itself and various items like cellphones and tablets.