> 6 | Design Advice

> 6.1 | Reducing Resistance between Battery and Module

> Generally, the PCB tracks connecting the module with the battery and, if used, a flex cable running from the board-to-board connector to the application, should be as short and low resistant as possible.
> To minimize the effect of voltage drops (max. 400mV recommended), you can decrease the GND resistance by using additional ground connections from the module to the customer application. This can be done by using a screw or spring contact.
> Typical resistance values are listed in the table below. These values increase up to 80% when the temperature drops to –10 degrees Celsius.

> Table 6: | Typical values of a battery application at 2A transmit burst

> Cause of the resistance | Measured resistance at 25°C | Voltage loss on module
> Battery and protection circuitry | ≈100mΩ | 200mV
> Battery spring connections | 2 x 6m Ω | 24mV
> PCB and B2B connector | 2 x 9m Ω | 36mV
> Total: | ≈130mΩ | 260mV