Im interested in putting together a project whereby and mpu6050 sends data to a mobile app with regards to spatial orientation. Due to the fact it would be worn on an arm, the size factor requires an attiny85. The mpu6050 is small enough as well but the battery would be an issue. The smallest batteries ive used before are those 3.7V LiPo:
But I think this might make it too bulky. So I was thinking of a coin cell battery like a CR2032 holder which would roughly be the size of the mpu6050.
I just remembered that Im still missing the ble unit and that is also very power intensive, so Im guessing the coin cell battery wont be good enough. Ive read they hold 230mah at best which and the MPU draws about 3mA and the BLE unit 30 mA. Im not sure how to put the numbers together because during constant operation both MPU and BLE would consume 33mA and Im guessing Id have to use those numbers because the idea is that the tiny determines if the device is oriented in a particular way and alert the phone so ... oh but tiny would only send the notification to the phone if the data is valid, otherwise there is no BLE transmission. Ok so then constant consumption would be 3mA (MPU) + 6mA (attiny) so around 10mA every hour so that would be about 23 hours of runtime without any ble data sending. I think this would be impractical because its a wearable and it would have to be recharged too often.
If I jump to a 1000maH with a 10mA draw thats 100 hours which is at least 3-4 days of use (without factoring in the BLE bursts, but those might be very few)
Any other battery options? Any tutorials on how to do this?