I would like to cobble together components to make a wireless alarm Motion sensor, transmitter, receiver all battery operated. Range 1000...

I would like to cobble together components to make a wireless alarm Motion sensor, transmitter, receiver all battery operated. Range 1000 feet. Run time six+ hours before recharge is needed. For example, driveway sensor connected to doorbell button. ignore a transmitter in the driveway sensor. or enhance the transmitter in the driveway sensor for range. t...

This is the relevant part of the schematic of an 18650 battery charger and boost converter (to 5V)...

This is the relevant part of the schematic of an 18650 battery charger and boost converter (to 5V) module: https://i.postimg.cc/Tw7X35Fq/USB-to-TP4056.jpg And here's the module: https://www.aliexpress.com/item/32870411748.html Coming from the USB power pin, there's a series Schottky diode and a very low value resistor. The resistor is found in the TP4056 datasheet typical applic...

I am using these 3S (12V) batteries with LED meter. Normally, the LED meter shows SOC (State of Charge). But when the SOH (State of Health) is...

I am using these 3S (12V) batteries with LED meter. Normally, the LED meter shows SOC (State of Charge). But when the SOH (State of Health) is low, the BMS cut off prematurely as low as 11V. I can still by-pass the BMS and charge it to 12V. I am wondering if it is doing that to alert the user to replace the unit. Basically using a single meter for both SOC and SOH, just to save a few LEDs. ...