This was the issue that wasted me several months tinkering. Obviously a solar battery powered node that needs a manual reset when drained is utterly useless and annoying. To eliminate this problem I use the Waveshare D solar power manager ( Solar Power Manager Module (D), Supports 6V~24V Solar Panel and Type-C Power Adapter, 5V/3A Regulated Output | Solar Power Manager (D) ) and my tests show it restsarts after brownout. I think the Waveshare D device will also let you work without solar and just charge the battery via the board so then it also springs back on when you recharge via USB, but this needs a test. Yes it is more kit but this solves the fundamental problem using off the shelf bits. (There are DIY solutions… ) And BTW I do not know if using protected batteries alone solves the RAK issue … but I use protected battteries as well as the Waveshare D solar power manager especially if I am thinking of putting a node in someone else’s house because it is a big responsability to hand over a li-ion powered device to another person in case of fire. In fact, some folks add a temperature cut-off device also e.g. https://amzn.eu/d/0fOf8utj
The BQ24074 and BQ25308 uses a NTC for temperature protection. But I read the spec of the Waveshare D and it says it already has these temperature and voltage protections… but I am not sure if it suffices. I would do both and also place the batteries / node in a metal child-proof housing preferably with a sand layer so it could burn and not cause anything else it touches to catch fire. This is of course a totally hard build so I don’t give DIY nodes with li-ion batteries to friends: they have to build them themselves. Never use broken batteries.
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