Guru
Joined: 13/10/2014
Location: AustraliaPosts: 1860
| Posted: 11:01pm 06 Jan 2023 |
Yes, they still have the reform procedure in the technical data that came with the caps, as you say, exactly the same way we did it years ago.
The new caps are below 45uA after 30 seconds, no problems there.
I tried reforming the nippon caps I had, also tried it at a lower voltage (always current limited) but five of them never dropped off below the 5mA current limit. When connected at their rated voltage after both reforming attempts, some immediately started to go into meltdown. They were the correct rated capacitance, you could arc weld with them, just totally unstable unless running at 2/3 of the voltage and very temperature sensitive.
If I had used them in a 48V (nominal) inverter build, they would have worked perfectly running at half their rated voltage, BUT - and it's a BIG but, any increase in heat, either self generated (heavy loads with high ripple current) or external heat from the rest of the inverter (likely both) and they would have eventfully exploded. God forbid running them in a loaded inverter on a 40deg summer day.
Aaron, interesting thing is, they held a partial charge, once the voltage dropped a bit the leakage current was low, but I never noted the voltage as it was a spur of the moment check before I put a screwdriver across the terminals to hear them go splat, and they did, then promptly threw them in the bin after cutting one open.