Maast
Compulsive Tinkerer
Fair enough, it's your system your building so you have to be happy with it. I'm just pointing out a much simpler solution, one I'm personally comfortable with. Though I do have to say invoking the UL is a bit specious.About 1 amp hour per month. If the cells have hit LVDC at 2.5, 1 AH will destroy the cells.
This type of configuration would never be UL listed. The entire load side will always be energized; of course I'd never touch stuff without first checking ... that's not the point. A fault condition should remove all potential.
Will it work? Sure. I'm not OK with this configuration. Some are, some aren't. That's why this thread isn't so cut and dry.
I prefer giving people education and options than to say "just do the following" - that's why this thread isn't only 2 posts - a question and an answer.
Some amplifying information, say you have a 'leaky' system and after a half-hour your system has stabilized at 80% of charge, that's ~40 volts giving a ~10 voltage difference through a 10kohm resistor and so your current would be 0.00102 amps. 1 amp hour would be 41 days.
1 amp hour out of a 48v 100ah battery bank with a (IMO more reasonable LVD) of 2.8v/cell would drain your battery down to 2.792v/cell. To reach 2.5v thats 153 days.
So I'll admit I did overstate how long it'd take as I hadnt actually crunched the numbers - 2ah would take 306 days if you had a 100AH bank.
Though I would hope that if somebody is going to leave a system unattended for that long they'd disconnect the batteries.
I'm thinking the best way for a person to find what their capacitor/system self-discharge rate is to do a bit of trial-and-error and see what their voltage stabilizes at and adjust the resistance up or down to where they want their precharge voltage to be held at, then take the value of the resistance and run it through a online calculator to find out what their 'leakage' current is to see if they're comfortable with it.
Here's one that I just found that'd help.