If you're looking for a giant battery, today is the day to pick one up, as a 20000mAh Anker is available at an all-time low price of $41.99.

Rather than just list the deals (Amazon already does that), we analyze the value of the discount and the quality of the product. Here's how we rate the deals to make it quick and easy for you to decide if they're worth getting:

• Must-Buy: The lowest price ever and a deal that hasn’t been seen often.
• Good: At or close to the all-time low, but has been available at that price other times.
• Decent: If you need one, it’s an okay deal, but the price isn’t much lower than its average.

If a deal is just bad (a price hike followed by a drop, a bad product, an extremely small discount, etc.) we don't feature it at all, so you can rest assured that anything we show here is at least worth a look.

We also use FakeSpot to determine the validity of user reviews and help you decide if a deal is worth getting based on the quality of the product as well as the price.

Anker PowerCore Speed 20000 ($41.99)

• Lowest Price: Today's Deal ($41.99)
• Average Price: $49.99
• User Rating: 4.2/5 (FakeSpot Grade: F)
• Deal Quality: Must-Buy

In spite of the low-quality review score on FakeSpot, we still think this is a must-buy deal. As a company, Anker has a B rating, so this could just be an outlier. It's also a newer product, so not a lot of users who weren't sent free devices have had a chance to write reviews.

That aside, you just don't see battery backups with such a huge capacity for this price too often. This one has always sold for $49.99, so $41.99 is most certainly an all-time low and a worthwhile purchase. If you're looking for a battery with Quick Charge support and the ability to charge your stuff multiple times without needing a refill, today is the day to jump in.