Simply DC

Passes off 5yo demo stock as new – I purchased a Baintech super capacitor jump starter from their ebay store and was sent an item with the security seals cut. The item had a large sale tag on it for much less than I was charged. The backup battery wouldn't stay charging until it was on the charger for 2 hours and even then it wouldn't hold charge. When I looked at the doco which came with the unit, it was qc passed in 2018. Super capacitors have an effective life of 10 years and lithium batteries around 4.

This seller made me pay the return postage and would not guarantee a refund. They only said they would test.