further unexpected experiment

Having now got the RAK Wisblock (RAK4631 on RAK19007 base) for use in the Anzio Catterick repeater and a battery I need to work on to change the connector to make it compatible with the Heltec Wireless Tracker I decided to plug that battery into the Wisblock (after repinning it to make the polarity correct) and topping up its charge before beginning the process of discharging it until the protection board kicked in (the battery is a EEMB 3.7V 2000mAh LP10454 flat battery), the battery as of this morning only hit 80% charged, meaning the discharge is generally quite low.

This suggests the RAK4631, because it uses the nRF52840 instead of the ESP32 most likely, is exceptionally efficient, the base board has LEDs on it but all these are turned off while the board is configured as MeshCore repeater (except the charge LED when the battery is charging which is controlled by a TP4054 charge controller), RAK themselves suggest that in transmit it draws at most 125mA, maybe a little more and when it is in sleep mode it is measured in microamps, in other words almost nothing and 17mA on receive (this is without the Bluetooth as we don't use the Bluetooth radio in these in normal operation for MeshCore repeaters).

The batteries I want to use are quoted as being 3400mAh each and these will be in parallel, in electronics when batteries are connected in parallel the current capacity adds up, a good example of connecting batteries in parallel is jump starting a car, this means that if these cells are indeed as advertised this could give a run time where the repeater once constructed will be able to run off the batteries at night and solar during the day all year round, exactly how we want the mesh to function, the batteries should total 3.7V at 13,400mAh if these cells are indeed as advertised, the runtime will also depend on traffic going through the repeater, but I've not heard of anyone having a repeater go down yet because of battery issues other than end of useful life.

The solar panel I'll be specifying for the repeater is rated 6 Watts but I suspect that is in full sun, something rare in the UK but modern panels are getting efficient due to the fact people want to use them more and more for silly reasons, small off-grid projects like these benefit from it massively, so if the unintended and unexpected experiment is to be believed then I don't see any repeaters on this mesh if built using RAK Wisblock hardware to really go down due to the batteries running out