DC-DC (48-24) with low standby or auto cut off

teotwawki.je

New Member
We have a "48V" system (14S Lithium Ion) which powers an All-in-one and both 24V & 12V loads via cheap DC-DC converters which are potted in a finned metal case. They work fine but although the 12V one only gets a little warm while in continuous use, the 24V one (for water pumps so mostly doing nothing) gets hot to the touch. We've measured its self-consumption at 5W which is quite an effective heater and annoyingly wasteful of battery power.

As there's only 2 water pumps and 24V is not needed 99% of the time, we're resolving it by buying another one & putting them both down-stream of a water pump switch. So each pump has its own DC-DC converter and they only run when the pump is in use. Solved.

However, I wanted to ask if anyone else has found a high (5W) stand-by consumption on the 48-24V DC-DC converters or do we just have a duff one?
Or does anyone know of a better one, which shuts down completely when there's no load?
Or does anyone know of something like an electronic demand switch which can disconnect the 48V feed to the DC-DC when there's no load on its output?

Thanks.
 

teotwawki.je

New Member
How many amps do you need? Victron has the Orion line of DC-DC converters that have a standby draw in the milliamps. But they aren't producing many amps. Their higher amp unit doesn't convert from 48v.

Good find but would be marginal on one pump let alone if both ran at the same time. I think (from memory) each pump is between 100 & 200W. So at least 15A, 20A would give good margin.
 
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