Meanwell RSP-750-27 or DROK 24V Power Supply

[Greg Norman]

I've been considering adding a Meanwell RSP-750-27 Power Supply for charging my 24v 280ah battery, but I have on hand a   DROK 24V Power Supply, AC 110V/220V to DC 0-24V 20A 480W Buck Converter, and an extra DSSR20. I checked the voltage from the DROK power supply, and it's 27.8v, which should be enough voltage differential to charge a 24v battery at 20a. I have one DSSR20 connected to two 60 cell panels. I will have the two DSSR20s connect to each other via the control wire. I'll feed DC from the DROK power supply through the second DSSR20. Am I missing anything or any suggestions?

[Dacian Todea (electrodacus)]

It is not clear if DROK 24V power supply has constant current limiting or not. If it is just a constant voltage limiting then it will not work.

This one here seems to have a potentiometer to set the current but still not a mention if it is constant current limiting or just over-current protection that is set. https://www.droking.com/drok-24v-power-supply-ac-110v-220v-to-dc-0-24v-0-20a-480w-buck-converter-volt-amp-adjustable-adapter-regulated-5v-12v-24v-volt-switching-voltage-led-transformer-charger

If it has constant current limiting then it will work as a charger trough DSSR20.

[Greg Norman]

i have  24V Power Supply AC 110V/220V to DC 0-24V 20A 480W Voltage Adjustable Adapter Regulated 5V 12V 24V Volt Switching Voltage LED Transformer 20A Amp Charger

• Product Code: 200571

[Dacian Todea (electrodacus)]

Your model is not a constant current limited power supply so it will not work as a charger https://thecncsource.com/en-ca/products/power-supply-drok-200571

So no it will not work.

[Greg Norman]

OK, I'll go ahead and purchase DROK Product Code: 200624. What is your recommendation for settings-voltage and amps?

On Saturday, June 22, 2024 at 1:20:06 PM UTC-5 electr...@gmail.com wrote:

[Dacian Todea (electrodacus)]

Set the voltage to max allowed so 27.8V will be OK as for current you will need to experiment maybe start at 10A or 12A to see how hot the DROK power supply gets. Not sure if it can handle 20A continues or if it will get to hot in those conditions.

The DSSR20 has no problem handling 20A continues.

[Greg Norman]

so do you think the Meanwell RSP-750-27 would be better as far as getting hot?

[Dacian Todea (electrodacus)]

I have no idea as I do not own any of them.  Meanwell is just a more recognizable brand.

The Meanwell is 750W vs 480W and Meanwell will not require the DSSR20 for remote ON/OFF

But Meanwell 750-27 costs about 300CAD at Digikey or 220CAD at Aliexpress https://www.aliexpress.com/item/1005003256370830.html

250*127*41mm  and 1.64kg  efficiency 90.5% so there will still be about 50W worth of heat at 500W load that is similar to a typical laptop

While Drok 480W 24V seems to be around 83CAD on Aliexpress https://www.aliexpress.com/item/1005004204538960.html

215*115*50mm  no mention about weight or efficiency may be around 85% but it is just a guess.