When Amazon runs Gold Box deals on USB battery packs, the offers usually aren’t as strong as we see regularly with promo codes from various manufacturers, but this deal is a major exception.

Two different battery packs from Poweradd are marked down to ridiculously good prices today. Get a 20,000mAh pack for $16, or a 12,000mAh model with a built-in solar panel and, uh, a built-in cigarette lighter for $18. For the former, deals of less than $1 per 1,000mAh are extremely rare, and for the latter, $18 would be a good price for that size battery without a solar panel and lighter.

These don’t have the latest features like USB-C or Quick Charge, but if you need a lot of capacity without spending a lot of money, you shouldn’t miss out.