Guru
Joined: 13/10/2014
Location: AustraliaPosts: 1846
| Posted: 09:44am 25 Dec 2022 |
Just sharing the result of testing some China caps, as others on the forums have already warned against.
I could not get any good caps at this time and tried my luck with some China caps, turned out to be just crap.
Test comparisons (older caps). Caps connected to a Linear Current limited tightly regulated supply.
Current draw when fully charged over at least 10 minutes (if they weren't trying to self destruct).
SPRAGUE 10,000uf 50v -likely 15 years since last used.
@ 50V = 5ma
@ 40V = 2ma
ELNA 10,000uf 40v
@ 40v = 0.25ma
@ 30v = <0.1ma
NIPPON 10,000uf 100v from Ali
@ 100V forget it - way too much leakage - some quickly getting very warm.
@ 90v most start to get warm, two drawing 100ma are getting close to running away with rising temperature.
@ 85v 6mA to 20mA most slowly rising in temp after a while. Two really bad ones just keep getting warmer.
@ 80v Between 3mA and 6mA and 6 of the 10 hold at that value.
My feeling is these are 70V to 80V rated caps and not the 100V as advertised (or just crap).
Might be OK for testing though as I will keep an eye on them, but not suitable in a final build. Would eventually cause an Inverter melt down on a hot day and/or sustained heavy load - even with forced cooling.
Mike.