So, recently I fried my old grid charger, so I decided to upgrade it.
Old design, using a pair of eBay no-name 90v LED drivers, a generic 12v driver, fused AC input, voltmeter, DC-DC converter (for isolation), old server power supply + fan. Harness had diodes in it, to prevent accidental death or (more importantly) damage to the charger.
Design changes:
Reused case + fan, 12v driver, DC-DC converter, multimeter, fused AC input.
Now discharge capable!
-Diodes moved from charging harness to just in front of the HV LED driver.
-Placed fast-blow fuses in harness instead, which allow discharge but still provide some protection, and more fuses where power enters/exits the grid charger.
-Unit now has a switch and a standard AC power outlet, for plugging in a lamp or shop light for discharge, and a switch to select either charge or discharge. Voltmeter works for both.
-Replaced 2x 90v LED drivers with 100-200v 500ma constant current Mean Well LED driver, which is about 8x heavier than the old eBay no-names.
EDIT: I'd like to change the 4-pin molex connectors I've been using to something a bit... safer? eventually, but haven't been able to find a set I like for the right price yet.