Parallel Buck converters

I want to connect my rPi VenusGX to run from my battery pack like a real GX.
For this I bought one of these boost regulators that can handle up to 60V @10A and bring it down to 12V.

Now I need to get from 12V to 5V@3A+ and it’s been too long (the week and the time since I last studies electronics) for me to remember.
Can you add two of these small buck converters in parallel to get to 5V with more than 3A? Or will they work against each other.
They can only do 1.8A continuous.

(alternative would be https://www.robotics.org.za/LM25696-MINI but I already have the other one)

Theoretically you can adjust them to match and then draw as much as you want.

In practise temperature variations will cause different deviations. You can add matched power diodes to mitigate, but you’d be wasting.

You can try something based on the XL6009, it has 4A max and the boards sometimes have heatsinks.

Or the LM2596HV takes up to 60V. I don’t really think you’ll need 3A anyways, unless you’re pushing the Pi very hard with lots of USB devices connected.

10A DC-DC 6.5-60V to 1.25-30V Adjustable Buck Converter Step down Charger Module | eBay ?

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For the same anticipated purpose I got this: (Not yet deployed)

That’s a nice one. FWIW, I’ve had great success with tiptrans.com ($5 off link) to consolidate Aliexpress packages in Hong Kong and then reship.

I have a 4 port USB hub and MK3, 2x BMS, 2x MPPT which is normally running. I’m getting issues when all the devices drop and suspect the 2A psu is giving too little power.

Phil, just run a Pi of it. Thats all. I had one. Work super nice with my pi till i added a small usb led light. Next day I here cracking sound in the garage. This was this little converter busy burning out.

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Yeah, that’ll do it.

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Why not just use something like this that can give you more than 3A.

Would like to but the battery is runing at 50V-52V and that model only go up to 40V. Seems like most only does up to 40V. But there are a few that do go higher.

There is a plase up in JHB side on bid or buy that is selling this one 200W 10A DC-DC Buck Converter Step Down Module 8-55V to 1-36 6V 12V 19V 24V 36V Voltage Regulator Sale - Banggood Mobile

Louis, other option is to find a car usb charge that is 3A, then you take the internals out to run it on the 12v

I think I know why you want the 3 amp but I truly don’t think you need it. I am running 2 times rpi Gx, each from his own Adjustable 2 amp DC-DC converter. One pi is running for over a year already and the second for a few months. I have no issues. These can peak at 3 amp but I don’t think you would ever get there.

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I would guess mostly because the official Pi power supplies are usually at least 2.5A, and many forums on the web points to inadaquate power supplies as the reason for instability in Pi’s.

Thanks for all the suggestions.

The Pi with the 6 USB connections is currently running from this 2.1A module but it is not keeping up.
https://www.robotics.org.za/MH-CD42 with an old iPhone battery.
That is running from a 2.5A 5v charger of the mains, but I would like to run from the main battery directly so any power failure will not infuence the GX system.

My serial devices loose power and then the GX sits there waiting for them.

From all the suggestions if I want to get something local it seems like the best option is

Else @Gman 's Banggood option or @Phil.g00 's aliexpress option

@Louisvdw I’m in the same boat. I need one for my pi that runs the MLT bridge software for the inverters

All good!
Your main converter reduces the voltage to 12V (and you’ll find this quite useful too!)
Then the smaller converter provides 5V. (For better pricing see: Other Electronics - Step Down Buck Converter MP1584 3A **LOCAL STOCK** for sale in Cape Town (ID:538508089))
I reckon the USB connection for your rPi isn’t an ideal voltage due to the current having to be so high to power it.
I have noticed that routers have virtually standardised on 12V with the 5.5 x 2.1 mm plug.

I was looking today aswell and was referred to this post by @Gman
atm found this one from mantech, but still only halfway through 1700 products, will edit or post another reply if i narrow it down, i am looking for 60v max down to 24(have some 24 led strips) then 5v for pi/arduino’s and maybe 12v for other rgd strips

Atm running an meanwell AC to 24vdc psu and stepping down to 12 and 5 where needed

https://www.mantech.co.za/ProductInfo.aspx?Item=372M0042

ENCLOSED, SINGLE OUTPUT, DC-DC CONVERTER IN:36-72V OUT:4.75-5.5V(ADJ) @ 3A(15W)

Are we seeing the emergence of the DC grid??

@Richard_Mackay can you elaborate more on your comment.

Why we want to use dc is because dc supply will be there constantly, so if the inverter stop working and the ac falls away, then the monitoring equipment can still run on the dc supply and you can do fault finding remotely.

I’m actually considering this for my Cerbo / RPI: https://www.takealot.com/gizzu-8800mah-mini-ups-dual-dc/PLID71930088

It’s got 36W output (unsure if fully available via single output). Don’t have one in hand, but could either take 5V directly or via converter from 12V. AC-powered from essentials side.

This way it’ll survive a BMS disconnect as well as inverter restarts…