Hi,
I was wondering whether lithium battery packs with multiple cells are okay to use with the Boron404x. Also, I am looking to get around 13000mAH battery to power my setup and was wondering if anyone had some recommendations for good batteries that I can use.
Yes, it is possible to use a multi-cell battery pack. See the battery guide for important information about the JST-PH battery connector polarity.
The battery guide does not detail multi-cell battery usage, however the Monitor One uses a 4-cell 18650 battery pack and has the same bq24195 PMIC and MAX17043 fuel gauge as the Boron 404X. You can't use the actual Monitor One battery pack on the Boron because the Monitor One uses a pack with a thermistor and 3-pin JST-PH connector.