I’ve been looking for a simple low-voltage cutoff circuit for a 12v SLA battery, but many of the ones I find have reviews saying that the protection circuit itself drains the battery slowly as well. Is this just inherent in the design, where it has to draw a little to measure the voltage, or are there low-voltage cutoffs that don’t draw anything until the battery is recharged?
i would probably do some circuit with a TL431 and FETs, but this also drains some small amount of battery current.