30 Volt 10 Amp Power Supply Broken—Dr. Meter

chrisski

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My 30 volt 10 amp power supply from Dr. Meter lasted 2 months and now there‘s a component that rattles around inside. I started the return process from Amazon. It was outside the 30 day window, so I had to message the seller directly.

9E27840C-5A82-4BE5-88AD-B44C3D0032E6.jpeg
This is a picture of the component that was rattling around inside. I think its a capacitor. One image shows where it broke on the board. Physically split in half with the problem half living to the right.. The other image shows the broke off half removed.

5F0D3DCC-F767-4022-9B8B-C3C2614AF75E.jpegB3CCB22F-4117-4A36-9ED9-C76914952C54.jpeg
This will set back my 24 volt lithium battery upgrade by a couple of weeks.
 

efficientPV

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Sep 24, 2019
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That is a standard 10A diode Looks like a 6A10. I buy 10A10, 1000V 500 at a time they are so cheap. That appears to be the protective diode on the output and blown up because you put a battery on backwards. Normally it is never used. Place those wires so they don't touch. If the supply still works replacing tat is an option. If it doesn't you have big problems. Test the output to see if it is shorted. The output rectifier may have shorted making this one blow.
 

chrisski

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That is a standard 10A diode Looks like a 6A10. I buy 10A10, 1000V 500 at a time they are so cheap. That appears to be the protective diode on the output and blown up because you put a battery on backwards. Normally it is never used. Place those wires so they don't touch. If the supply still works replacing tat is an option. If it doesn't you have big problems. Test the output to see if it is shorted. The output rectifier may have shorted making this one blow.
That is exactly the kind of comment I was hoping to hear.

The supply does still work.

I don't know what type of loctite they used to secure the circuit board in there, but the screws are so tight I will strip them to take the board off to replace it. I had to drill one of the screws out to get the cover out and its a tiny screw in sheet metal.
 

chrisski

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What is printed on the body of the diode?
Other than what is on the picture, 6A10 on the first line and AIC, I'm not sure.
Same thing happened to mine the minute I plugged it in. Let the smoke out and that cap broke.

Other than what @efficientPV said, I'm not sure.
That is a standard 10A diode Looks like a 6A10.

Same thing happened to mine the minute I plugged it in. Let the smoke out and that cap broke.


https://smile.amazon.com/gp/product/B087CJZTXJ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1
That q8 seems pretty nice with 30 charging amps, but the Q8 needs a DC input, so seems you needed to get a AC to DC converter to act as a power supply for the Q8.
 

LVLAaron

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Other than what is on the picture, 6A10 on the first line and AIC, I'm not sure.


Other than what @efficientPV said, I'm not sure.



That q8 seems pretty nice with 30 charging amps, but the Q8 needs a DC input, so seems you needed to get a AC to DC converter to act as a power supply for the Q8.
Correct. I had several options (AGM batteries) and just connected shore power chargers to the AGM's
 

2BZ2Ranch

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Flagstaff, AZ, U.S.A.
Just out of curiosity, what will be the problem if that diode is not replaced?

I once had the voltage incorrectly set on my PS and there was quite a spark, however, the power supply still worked so I finished my charging. Yesterday (a couple of months later after the “spark”) I was using the power supply again and noticed a little black chip fell out. After opening the power supply I noticed that the D30 diode was broken as shown in the OP. I was going to do a post when the “suggestions” brought me to this thread (I really like this forum).

If I understand @efficientPV saying “replacing tat is an option,” ;) does that mean the diode is actually a “fuse?” What is the purpose of that circuit?

BTW, I’m using the PS as I write this and it appears to be working normally.
 

efficientPV

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This diode reduces current going thru the supply's transformer and rectifier in the event you place the connections revere on the battery. It is just in parallel with the supplies output and normally does not see any current. As you see it saved your power supply. If you never do anything stupid, it doesn't need to be replaced. Should that not be the case, the next time you connect it wrong, it will be destroyed. It is a 5 cent part for me. Couple bucks for you after shipping.
 

Maintenance guy

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I would bet money the diode is from China and a knock off of a real diode. get a name brand one to replace and your good.
no diodes are not fuses, they are a one way current device allowing to flow from cathode to anode only. if he hooked the bat up backwards it could of exceeded the rating and blown because the battery will win every time knowing some are capable of hundreds of amps delivery.

PS. i thought the diode give alternative path other then the transformer when bat is hooked backwards.?
 

2BZ2Ranch

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I would bet money the diode is from China and a knock off of a real diode. get a name brand one to replace and your good.
no diodes are not fuses, they are a one way current device allowing to flow from cathode to anode only. if he hooked the bat up backwards it could of exceeded the rating and blown because the battery will win every time knowing some are capable of hundreds of amps delivery.
It was just a tongue-in-cheek comment. I knew what a diode was. What I didn’t know was the circuit.

In the old days it was said that the television’s 200 dollar CRT was there to protect the 59 cent fuse.
 

chrisski

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I returned this power supply through Amazon and the company honored the exchange.

On a separate note, while top balancing this Dr. Meter Power Supply voltage setting has drifted slightly when I set the voltage on about two out of 50 cells I have top balanced. The first one drifted from 3.65 to 3.69 on one of my cells. The second Power Supply drifted to 4.1 volts while top balancing lithium cells. I caught it before it went too far. I am setting to 3.65 prior to connecting.

When top balancing with this, I check as much as I can.
 

2BZ2Ranch

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I returned this power supply through Amazon and the company honored the exchange.

On a separate note, while top balancing this Dr. Meter Power Supply voltage setting has drifted slightly when I set the voltage on about two out of 50 cells I have top balanced. The first one drifted from 3.65 to 3.69 on one of my cells. The second Power Supply drifted to 4.1 volts while top balancing lithium cells. I caught it before it went too far. I am setting to 3.65 prior to connecting.

When top balancing with this, I check as much as I can.
Yeup! I never leave it alone. I disconnect and turn off before walking away.
 

Riderice

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Aug 25, 2021
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Hi, I'm having a similar issue, except my diode seems intact...and I don't see anything else obviously burnt/singed/blown on the inside.

After using my Dr Meter to top balance 16 LiFePO4 cells, on the verrrry last cell (exhausted after 9hrs of balancing), as I was disconnecting everything one of the leads must've touched another cell terminal... Got a big spark and smoke at the lead, and the wires were instantly super hot. The Dr was still on and looked okay, but doesn't sense voltage when the leads are connected to a battery, and I can't adjust voltage up with the knobs (so, not really working anymore).

I was hoping to find a fuse blown (or diode) to replace, like OP, but no... Any ideas?
 

chrisski

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If you feel lucky, you can order and swap the diode. I doubt it always breaks when it’s bad. If that diode is there for reverse current, perhaps it blew.

I did not order the diode, but found it for sale on Amazon or EBay. A few dollars, which is more than mentioned.

To test a diode, ohm one way and then swap the leads. High resistance one way and almost no resistance the other way.

There is also the diode tester selection on the multimeter.
 

Riderice

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So on that diode (D30) I get almost 0V in both directions using multimeter diode test, indicating that it's toast. Whereas other diodes on the board I tested, I get 0V one way and 0.6V the other (expected for a good diode). So, I guess I'll try to get my hands on a new one and replace it. My soldering skills are terrible though, I give myself 50/50 odds 🤣
 
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