2. The Device
Collected meters
Battery life (years)
-
AA cell (3Ah) Baby cell (9Ah)
1
10.7
32.0
5
7.0
21.1
10
4.9
14.8
20
3.1
9.3
40
1.8
5.3
80
1.0
2.9
Table 1: Battery life for daily LoRaWAN uploads with SF12
Collected meters
Battery life (years)
-
AA cell (3Ah) Baby cell (9Ah)
1
12.1
36.4
5
11.8
35.4
10
11.4
34.4
20
10.6
31.9
40
9.4
28.3
80
7.7
23.0
Table 2: Battery life for daily LoRaWAN uploads with SF7
Estimations for the opposite situation with a excellent LoRa link quality and thus the possible
usage of SF7 are also presented in table 2.
In real world installations the possible spreading factor may be optimized anytime by setting
up additional LoRaWAN Gateways near the meters of interest.
2.3.2. Usage scenario recommendations
As a simple rule of thumb using the Lobaro wireless M-Bus over LoRaWAN bridge is a good
t in applications that require daily (or less often) consumption values of 1 to 40 installed
wireless M-Bus meters. For installations with a higher meter count simply more Lobaro
bridges may be used.
Another key factor for high battery lifetime is to select or congure your wireless M-Bus
meters in a way that they send short telegrams very frequently, proven good values are
periods smaller than 30 seconds and telegram sizes smaller 50 bytes. This helps to minimize
the needed wMBus listening time period and avoids the need for multiple LoRaWAN packets
per single telegram (data splitting).
wMBUS over LoRaWAN Bridge
6
