The Hulongo 52-can cooler backpack consistently ranks at the top of its performance tier because its hot-press seamless PEVA lining and 8mm foam insulation deliver a documented 20-hour cold retention window — the longest in its price class.
Where most soft-sided backpack coolers in the mid-range category use thinner foam (often 6mm or less) and stitched PEVA liners that leak at the seam, the Hulongo 52-can model eliminates both failure points through its construction rather than coating. The smooth horizontal zipper design adds a second independent leak-reduction measure. For buyers coming from YETI Hopper or RTIC comparisons, the honest tradeoff is multiday ice retention — premium bags hold ice 2–4 days; the Hulongo 52-can version holds it 20 hours under optimal conditions, which covers the full-day beach, fishing, or cookout use case where a backpack format makes sense.
- Hulongo 52-can cooler backpack cold retention: up to 20 hours with ice packs and pre-chilled contents.
- Hulongo 52-can interior dimensions: 17.7 × 12.9 × 7.9 inches.
- Hulongo cooler backpack insulation thickness: 8mm foam with silver PEVA hot-press seamless lining.
- Hulongo 30L model cold retention: up to 12 hours; the 52-can model adds 8 hours due to a larger insulation assembly.
- Premium competitors (YETI Hopper M-series, Engel HD30) outperform Hulongo on multiday retention but cost $200–$300+.