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brulaz's avatar
brulaz
Explorer
Jul 15, 2017

Meanwell PS creates a load?

Recently realized that my solar systems daily output had increased by ~50Wh per day when in storage with no shorepower.

It was hard to believe that the parasitic loads or the battery self-discharge had increased by that much as the only change I had made was to install a Meanwell 27V 500W adjustable power supply to charge up my 24V battery bank when on shorepower. I assumed that when it's unplugged from 120VAC the Meanwell would have no load on the batteries, so I hard-wired the DC output through a fuse block to the 24V battery bank.

But after pulling the DC fuses in the Meanwell's output, that new 50wh per day load has disappeared. (Someday I'll have to measure its actual current draw with my clamp-on.)

Do other PS/charger/converters do this? I don't recall such behaviour with the WFCO or Prog. Dyn. when boondocking, but never really looked at it closely.

Anyway, it's not that big an issue as I don't need the Meanwell that much. Usually solar supplies everything we need, so I'll just leave the fuses out until it's needed. But it is unexpected.
  • rough guess 0.125 amps

    bleed down circuit across the output of the meanwell ?

    why pull the fuses ? the batteries are being maintained .. correct ?

    expecting a string of bad weather low solar days, that you can Not recover from ?
    i would think that this is no different than any other charger/converter/power supply, they all have bleed down resistors of some kind

    we just never notice a difference in our 12v systems, because it is already there and we don't disconnect the converter from the circuit
  • With the DC connected, you still get power to run the fan in those converters/chargers that have temperature controlled fans. The unit can be hot enough to need the fan without actually charging anything.
    Also, (some of) its capacitors stay loaded (might be wrong about that)

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