Electronic – Coin cell battery for Bluetooth


I'm trying to determine which battery to use for my application. I'll be using a class 1 or class 2 Bluetooth (not low energy) module, which requires about ~50/60mA of RX/TX current. In addition, there is a microcontroller and some low power analog IC's. I require a continuous stream of data from the device for 1-10 minutes.

Are coin cells completely out of the question? I'm talking about CR2450 Lithium-ions. I don't really mind if they don't last long, but will they work? Because in my application, size is key, and battery life is a trade off that I'm willing to make.

Best Answer

No, they won't work. CR cells are designed to deliver maximum a few mA continuously, so a low power microcontroller like an MSP430, for instance running off a 32.768 kHz crystal, may work, but the power for an RF transceiver is much too high.

The datasheet for this battery even specifies only 0.2 mA as "continuous standard load".

If you would need your RF in short bursts then you could get the power from a large electrolytic capacitor, for say 100 ms, and then recharge it over a longer time, so that the controller still gets enough current. For continuous streaming this won't do.