back to deep discharge protection

XH-M609:


This is really inexpensive 12-36v, 20a programmable low-voltage-cutout switch. It uses a relay to switch on and
off, and has an onboard display with two push-buttons for adjusting the cutoff voltage. It draws 10mA when off
and 70mA when on.

Setting the off/on voltages for this board is a little weird though. Most adjustable boards let you set the off
and on voltages separately. On this board however, you need to set the median voltage between off and on, and set
the offset that goes down from median to off and up from median to on.

To disconnect the battery at 10.8v and reconnect at 12.4v, set the median (left button) to 11.6v and the offset
(right button) to 0.8v. The separation between off and on voltage provides "heuristics" that should help prevent
the battery from being rapidly switched on and off when it is near the cutoff voltage.

DO NOT use this to disconnect the battery from a solar controller. If you do, and the battery drops to cutoff,
the controller will be disconnected from the battery, which may damage it. (most controllers already have a low-
voltage cutoff that disconnects the LOAD if the battery voltage falls below its set-point)


xh-m609 (2pcs for $8 on Amazon)

xh-m609.pdf (326 KB)


xh-m609:



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