Unregulated power supply creating buzzing noise. No idea why...

[evoheyax]

Hi, so I was using this 48v (10amp max) charger to charge my 15ah headway 14s1p pack:

https://www.amazon.com/Adjustable-Converter-110V-220V-Switching-Transformer/dp/B0777MH681/ref=sr_1_8?ie=UTF8&qid=1535136629&sr=8-8&keywords=48v+power+supply

And after a few weeks of use (maybe 50 full charges), it kicked the curb. This was after making some weird humming noise for a few days. Now, I'm using a completely different power supply, also 48v (10amp max):

https://www.amazon.com/gp/product/B078VYMRKG/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1

I'm borrowing this from a friend, and after a few good uses, it also started today creating a humming noise. In both cases, the humming noise leads to a bad smell... The second one hasn't kicked the curb yet, but it's frustrating as I use my ebike for work, so I need reliable (yet fast) charging.

Does anyone have any ideas as to what could be going on here to cause this weird issue? Or recommendations of a high amp charger that would work without this problem?

 

[markz]

Buy a Meanwell PSU I use two HRP-300-24 connected in series with no modifications required. It is CC/CV.
I have abused mine, dropped them, shorted the + and - while probing voltage while charging and they still keep going.
I have let them sit for hours and hours on a 40 minute to full charge, and they shut off automatically. You can set the voltage but not the current. They are 14A charge current so a little more then your 10A.

I carry them in my backpack and for long life of battery pack, best to charge whenever you can to get shallow discharges. Makes your batteries last a long long time.

 

[fechter]

When charging a battery, the battery starts out at a lower voltage so the supply has to run at the current limit. Those supplies are not really made to run at the limit for any length of time. The current limit needs to be lowered enough so it doesn't exceed it's continuous power rating. There are some topics around that show how to make the current limit adjustable so you can lower it. The design of the supply seems to change on a monthly basis, so it may or may not be easy to figure out where to attach the adjustment pot.

I use a similar supply for my charging and lowered the current limit so the supply doesn't exceed it's power rating. It works great and has been in use for several years.

Supplies made for LED lighting are generally made to run at their limit continuously.

 

[amberwolf]

Meanwell HLG-600H-54A would do what you want. Up to 11-12A, up to 56-58v, at the same time, 600w minimum continuous output. I use one on my SB Cruiser trike, built into it (mounted on the bottom; it's tough).

No modifications needed, just add connectors, and adjust the rubber-covered pots to the voltage you want, and then the current you want. Clockwise for higher.

 

[evoheyax]

Meanwell HLG-600H-54A seems like a good one. Just a bit pricey though.

Thank you for the responses everyone!

@fechter The one I'm using right now says the limit is 500w. But the watt meter I'm using says 489w while charging, so I'm not exceeding the limit. If they say it can do that, to say power a security system as they recommend it's use for, why is charging a battery so much different? Sorry, not trying to be rude, just want to understand what's happening a bit better.

 

[fechter]

If you are under the rated limit, then it's supposed to be OK.

In real life, the ratings are probably exaggerated, so you need to lower it to about 80% of the rating for good reliability. If it was a top quality ($$$) supply like a Vicor, then you could expect it to run at 100% continuously. Whether charging a battery or running a computer makes no difference to the power supply except when charging a battery, the supply will be pegged at the current limit for hours at a time.

 

[flippy]

Meanwell HLG-600H-54A seems like a good one. Just a bit pricey though.
Thank you for the responses everyone!

pricy but you get what you pay for. you can drive a truck over them and they still work. i know because i tried.

 

[evoheyax]

Just went through another cheap one I posted above in under a week. Ordered the meanwell 600-54A, so we’ll see if my problems persist. Thanks everyone!