ONETAK NEMA 14-30P to 5-15R 5-20R 6-15R 6-20R Compact 240V 30 Amp 4 Prong Male Plug to 240V 15 Amp 20 Amp 3 Prong Female Receptacle Outlet Generator Welder Dryer EV Charger Power Cord Adapter

Does your current portable have 2 different cord options? If so, it's a dual voltage unit. You could get a 14-30 (the receptacle you currently have) to 5-15 (regular wall plug) adapter. You'd then use the regular wall plug on your portable charger to set the amperage limit to 12a. So you'll get 2.8kW charging. https://a.co/d/0brfhnLM