Hi all,

I asked a little while ago about making a simple low voltage cutoff circuit
- thanks for all the help.

I've finally got my hands on the kit, and it is a single cell external
battery with a built in protection circuit. This plugs into a tracker which
has it's own internal battery and the idea is that once the external
battery has discharged it switches to the internal battery, however this
never happens.

I've pretty much nailed down the issue to be that the tracker browns out at
about 3.3V. Therefore the external battery is never hitting the cutoff in
the built in protection circuit. The tracker is also not switching to the
internal battery (as it will do if I switch off the external battery) as it
continues to try and use the external battery despite it not having enough
voltage to run it properly.

So we come back to the need for a cutoff circuit, with required cutoff
about 3.4V, required current very low. But it occurred to me that all I
actually need is a single cell protection circuit with a custom cutoff
voltage. to replace the existing one - which would be a far neater
solution. So does such a thing exist, or is there any way to modify a
standard circuit to do that?

Thanks,

Chris
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