On Saturday, 27 June 2020 16:05:50 UTC+1, T i m wrote:
On Sat, 27 Jun 2020 07:22:11 -0700 (PDT), tabbypurr wrote:

true

Assuming you're charging a lead acid battery and it's not SLA, 5w is not enough to need a controller. A diode stops any discharge.

True, but it doesn't prevent any overdischarge of the battery?

yees

The trick is to find a LVD solution that doesn't draw any significant
current itself, or find one where the LVD draws far less than any
potential load.

A latching relay / circuit might be such and could be used to
disconnect itself and the load when the LV threshold was detected.

Cheers, T i m

I don't recall the op requesting a discharge protecting relay. If he wants one, I would not regard it as a trick in any way, just some basic electronics. A bistable relay can eliminate most of the current draw. Drive it with a low current opamp, 2 transistors or fets & 2 big caps and Robert's your relative.


NT