Battery alternatives for Thingy:91

[Torje]

Hi!

I'm looking into making my own casing with a bigger battery pack for my Thingy:91.

It seems like the included battery has some circuitry which enables it to deliver both 3.3V and 1.8V through three pins on the battery connector. This makes it hard to find a replacement battery. Do you have any insight or recommendations on how to use bigger battery packs for it?

And out of curiosity, why is it made like this? It seems a more sensible solution would be to make the voltage level shift on board, and not externally.

Thank you all!

Kind regards, 

Torje

[Sigurd Hellesvik]

Hi Torje

The Thingy:91 features a PMIC which is used to charge the battery and regulate the voltage for the board.
See the Thingy:91 documentation: Power supply.

The full Thingy91 hardware schematic can be found at Nordic Thingy:91 Downloads.

From the datasheet of the PMIC, it seems that the ADP5360 is designed for:
" The ADP5360 integrates a fully I2C-programmable charger for single-cell Li-Ion/Li-Poly batteries suitable for a wide range of portable applications."

I recommend that you look at the ADP5360 to get more details on which batteries you can connect to the Thingy:91.

When choosing a battery for the NRF9160, it is important to keep in mind that is should be able to provide enough current for Peak Current consumption of the nRF9160. See the Modem Current Consumption from the nRF9160 Product Specification.

Regards,
Sigurd Hellesvik

[Torje]

Hi,

Thank you for answering. It seems battery replacement is a bit of a hassle because of the thermistor. If we changed the battery, we would need to adjust the PMIC with the values of the new thermistor.

Do you have any resources for how this is done with the PMIC connected on the Thingy? 

Kind regards,

Torje Johansen

[Sigurd Hellesvik]

Hi,

For the Thingy91, the ADP5360 is configured in https://github.com/nrfconnect/sdk-nrf/blob/main/boards/arm/thingy91_nrf9160/nrf52840_reset.c, where functionality comes from https://github.com/nrfconnect/sdk-nrf/tree/main/lib/adp536x.

I would not recommend that you make changes to the SDK for this though, so consider making a new custom board for your new battery, or calling the needed functions from the adp-driver from your code directly.

Regards,
Sigurd Hellesvik