You can apply 1A and the battery will decide what voltage that produces across its terminals.
You can apply 16V across the battery and the battery will decide how much current that drives through it.

But if you do either of those and the voltage or the current is anywhere near the maximum specified, yo should watch the process carefully because conditions will change fairly quickly when charging a good battery, especially a smaller one. Also, feel it occasionally to see if it starts to get hot, and if it does, back off the charge rate.

 

Hello,

About 2 years ago I purchased this 30V/5A DC Power Supply and for most of that time it's done a great job. Lately, however, it seems to be having more and more problems.

It is becoming very difficult to set it to a specific voltage
It seems to have lost it's ability to be set to most any voltage, but especially lower voltages under 5v for example.

I'm wondering if there's any "common" components in these inexpensive Power Supplies that I might be able to change to remedy this.

Alternatively, I could open it and see what's inside.
I was hoping some of you guys may have one of these and might be familiar with it.

any suggestions appreciated.

Here's a picture of the POTS.
There are no marking on the POTS other than the letters WL

Replace the pots with wire wound multiturn pots. You"ll be good for the next couple of years.

 

Don't set the voltage to 16V. You stand the risk of destroying your battery.

Set the power supply voltage to 14.5V.
Temporarily short circuit the power supply (jumper betweem + and - terminals) and set the current to 1A.

Monitor the current as the battery charges. When the current drops below 0.1A, set the voltage to 13.5V for float charge.
Disconnect the battery after 4 hours on float charge.

Here is what happens when a "smart" charger fails to be smart.

 

Don't set the voltage to 16V. You stand the risk of destroying your battery.

Set the power supply voltage to 14.5V.
Temporarily short circuit the power supply (jumper betweem + and - terminals) and set the current to 1A.

Monitor the current as the battery charges. When the current drops below 0.1A, set the voltage to 13.5V for float charge.
Disconnect the battery after 4 hours on float charge.

Here is what happens when a "smart" charger fails to be smart.

Oh Wow!!! It shows that those batteries did not have working pressure relief valves, because they are not supposed to swell up like that. Probably everybody who uses batteries should be warned about that brand of battery, and also that model of charger. If those had burst it could have been terribly messy indeed.

 

Don't set the voltage to 16V. You stand the risk of destroying your battery.

I have an Optimate (highly rated) 12v battery charger / desulfator. They've been reviewed by many experts.
Depending on the level of Sulfation, they apply a 16v or 22v current to the 12v batteries for desulfation. Maximum current is 0.8 Amps

I was trying to duplicate the desulfation process with my CC/CV DC power supply. (maybe not a good idea)

 

Don't set the voltage to 16V. You stand the risk of destroying your battery.

Set the power supply voltage to 14.5V.
Temporarily short circuit the power supply (jumper betweem + and - terminals) and set the current to 1A.

Monitor the current as the battery charges. When the current drops below 0.1A, set the voltage to 13.5V for float charge.
Disconnect the battery after 4 hours on float charge.

Here is what happens when a "smart" charger fails to be smart.

Scary stuff there. Coulda been MUCH worse depending on where they were charging.

 

I am not familiar with that charger.
Here is what I use: NOCO Genius G750
(Edit: Not the one used to destroy the above batteries. I have had a number of SLAB destroyed by over charging when the chargers failed to turn off, from different chargers.)

 

Years ago where I worked, there were similar looking batteries when someone hooked a 12V SLA up to the NiCad charger.

 

So,
Thanks to everyone who helped with this issue.

As a follow up, replacing the Pots seems to have returned to unit to it's original condition.
It's working great again now, down to even 1v (never really could do it before)

So, this thread can maybe serve to help those who have these CC/CV DC power supplies and find they are having troubles.
If you have one and prefer just to dispose of it and buy a new one, please send them my way instead. save the planet.

Thanks again everyone !

 

It is amazing how far this thread wandered, all the way from a power supply problem to battery destruction.

 

It is amazing how far this thread wandered, all the way from a power supply problem to battery destruction.

Forum threads are like a box of chocolates, you never know what you're gonna get....just enjoy, and expect it to get messy at times

At least you won't get acne or gain weight from messy forum threads.

 

I own a similar looking but higher output supply and now I am wondering about how long those controls will last. It needs to run with 240 volts because the max output settings are 50 volts at 50 amps. Not sure what I would use that much power, 2500 watts, for, but the price was right and there were no problems that reading the instruction manual did not clear up. The nice feature is that for lower voltages and currents it seems to operate quite well on 120 volts. But that part is probably better left to a different thread.