The same company to produce construction equipment and other industrial tools also has a line of durable mobile devices meant for demanding work environments. While they don't really feature the types of bells and whistles that get enthusiasts excited, Cat phones do have a key feature that many flagships lack.

The Cat S41 is an upgraded version of the previous S40 smartphone. The S41 packs a sizable 5,000mAh battery that also doubles as a power bank you can share with other devices. Good for up to 38 hours of talk time, it's safe to say that this phone can truly go all day.

Moving down one step below the flagship is the Cat S31 which replaces the S30. It's a bit cheaper and has a smaller 4,000mAh battery but most of the durability is retained. Both the S41 and S31 are MIL-STD-810G and carry an IP68 rating.

Enthusiasts looking at the S41 or S31 as a way to get a durable phone with a big battery should know that there are some significant drawbacks.

For example, both phones lack 802.11 ac support (the S41 is limited to dual-band 802.11 n and the S31 to single-band only). The S41 has a 13MP rear camera but tops out at 1080p video recording at 30fps. The S31, meaenwhile, shoots 8MP rear stills and only 720p video at 30fps.

The Cat S41 commands £399 (around $515) while the S31 asks £299 (roughly $386). Details on availability are expected to be announced at IFA next week.