Battery life on nrf52840 using meshing.

[Robbylaw]

I have developed a ble5 long range and meshing product but my life is way to short. using 2-3.6v batteries in parallel and only getting 2 months life in my battery calculations and I know I should be getting a lot more can anyone help me ? 

Battery Lifetime Report

 

 

For a week

Function	Description	Current consumption	Unit	Duration	Periodic
BLE Radio	GDM Open Alarm	10.8	mA	24 hours	24 * 7 hours
	Close Alarm			280 s
Sleep mode	Wake on GPIOTE input	2.36	uA	Rest

- Battery

3.6V 1.2 Ah * 2

- Current consumption for a week

Sum = 10.8 * (24 + 280 / 3600) + 2.36 / 1000 * ( 24 * 7 – 24 – 280/3600) = 260.38 mAh

- Lifetime

Lifetime = 1200 * 2 / 260.38 * 7 = 64.5 days

 

 

 

Therefore, battery life time is about 2 months

[Hung Bui]

Could you describe your mesh network ? Which nodes are relay node, what is the communication between them ? 

As mentioned by Marciano, relay nodes and normal mesh nodes require main power. You can run a low power node on a battery. But this node can't relay mesh message. 

You mentioned that with Bluetooth 5 you have longer range, which feature of Bluetooth 5 you used that improve the range ?  

[Robbylaw]

Ok I have a transmitter mounted to a garage door using 2-3.6v batteries in paraelle when door is closed transmitter is in sleep mode when door opens transmitter awakens and send signal to receiver (nodes) . the receiver starts to blink LED lights and make a beeping noise. the distance in range with just one node is about 90 feet indoors then another node further. the receiver nodes are plugged into a usb wall charger and have full power supply at all times.  but battery life is way to short. I am not sure what you mean by what feature of bee long range I am using ? we are using the blue nrf52840 chip with long range and meshing. the nodes are not running on battery only the transmitter. and it is in beacon mode. 

[Marciano-PL]

If your tx device is not expected to ever need to pass along messages for another device, it would be quite viable to employ the LPN example code. When LPNs go to sleep, they turn off the radio rx that mesh requires, meaning your sleep current could be below 10µA. You could also just deactivate mesh on your device manually if you don't need the friend node capabilities. Here is a ticket showing how to turn off mesh. https://devzone.nordicsemi.com/f/nordic-q-a/57450/reliably-disabling-mesh-stack-quickly-for-low-power 

I would definitely consider reading into the friend + LPN features because they sound like they would accommodate your project well.

[Hung Bui]

Could you clarify are you really using mesh or you are just using Bluetooth Low Energy (start network, point to point, one central node and multiple peripheral node) ?

If you are using mesh, which technology are you using ? How many node in the network ?

Could you explain what is the "Open Alarm" and "Close Alarm" ? Why the duration is 24 hours and 280s ? Even if the duration of the alarm is 24 hours, you don't need to transmit data all the time, continuously for 24 hours, correct ? 

Please describe in more detail the "Long Range" mode you are using, what radio configuration do you have ? Which output power ?