Prevent Battery Drainage Beyond Cutoff Voltage in XH-M609 Circuit

[thatdecade]

There is an issue with the XH-M609 low voltage protector circuit where it continues to drain the battery past the set cutoff voltage if you forget to turn the fuse off. I measure 20-30mA when the circuit should draw 0.

This results in the battery over discharging after play. I have lost a few batteries this way. Manual charging / Jumping was not able to recover the bad battery, boo.

Proposed Solution:
Add a Solid State Relay (SSR) in front of the XH-M609, coupled with two power diodes like the 1N4002. The SSR is initially activated using an ignition pushbutton. This setup allows the XH-M609 to initially power up via the switch, and subsequently, the XH-M609/SSR combo will keep itself powered until the voltage drops below the critical level. At which point it will fully disconnect.

I have tested this, and once the XH-M609 reaches the cutoff voltage, the SSR turns off. I measure 0uA on my meter.

More details on the SSR/XH-M609 wiring here: Electro-Tech-Online Discussion.

Make sure you use a DC DC SSR. The DC AC ones will not work. My SSR came with a big heatsink :) https://amzn.to/3W45Jsh #ad