RTK Facet not charging

I bought it almost 18 months ago, it was working fine but now it no longer charges. What could be causing this, if it connects via serial to the computer but does not charge the battery. I was thinking of connecting the battery directly with an auxiliary connection but I don’t know if this would work. What would you recommend to me?

My first guess is that maybe the battery is failing, or perhaps has become disconnected inside? https://docs.sparkfun.com/SparkFun_RTK_Firmware/repair/ You could pull it out and test it to see/verify, and if it is bad replace it (this is the OEM one https://www.sparkfun.com/products/13856)

Additionally, the charge circuit may be having issues. If you determine that the battery is not the problem, please start a return (https://www.sparkfun.com/returns) and we can have the unit inspected and repaired.

I already checked the battery and there is no problem, so I think the charging circuit is the problem. I cannot send the unit for repair due to the difficulty of shipping from my country.

I could install a battery charging module, maybe a TP4056 for direct charging, I don’t know if there would be any problem doing this.

Understood. The Facet main board is available for separate purchase here: https://www.sparkfun.com/products/24675