I have 14. The cameras use 1-2MB per minute in SD video or 4-7MB per minute in HD video (only when being viewed or uploading a clip to the cloud). Bear in mind that SD/HD for WyzeCam does not refer to video resolution. Video is 1080p in both cases. The SD/HD refers to compression ratio with SD being more highly compressed. The result is that in a lot of circumstances, it is hard to tell the difference between SD and HD. When you do see a difference, it is a variation of the compression artifacts (blockiness) that can be observed, not details or edge refinements.
Only when motion and/or sound detection enabled, 15 second clips are uploaded to the cloud. Then there is a 5 minute cooling off period before the next clip will upload. The cooling off period limits the amount of data that is stored in the cloud. Given that Wyze provides this cloud storage for free whereas most other cameras charge monthly for cloud storage, I find this to be reasonable.
You can install a microSD card in the camera and have it record continuously or only for motion/sound alerts. When the card is filled, the camera erases the oldest clips automatically. Alert clips recorded to the microSD card are not subject to the 15 second / 5 minute rules of the cloud videos. They record continuously as long as motion and/or sound is detected, until the card is full.
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