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Daly smart BMS

Thanks for making your point and below are my results....I am either having an operator error or?? The PS can send 10A to the battery, but the issue is at what voltage...thanks kind sir.

Set the power supply to 3.65v using your meter to measure the voltage while not connected to the cells.
Connect the power supply to the cells, observe 10 amps out, ignore displayed voltage, notice constant current LED is lit.
When voltage gets close enough, display will change to voltage, and constant voltage LED will be on.
 
That is normal behavior .... the power supply can't maintain
Thanks for making your point and below are my results....I am either having an operator error or?? The PS can send 10A to the battery, but the issue is at what voltage...thanks kind sir.

(y) That's REALLY good to hear.

I wouldn't worry about the voltage reading on the power supply dropping when you connect the leads .... I would consider that normal ...Just keep doing what you are doing .... You are now getting about 10 times more power into the battery than before.
The voltage reading will come back up once the current starts to drop off .... just don't touch that voltage adjustment after you connect it.

edit .... Just saw Just John's post .... what he said.
 
The power supply only can give you 10 amps the batteries can take a lot more than the power supply can put out so to keep the power supply from overloading it will change to CA mode if it did not do that it will burn up as the batteries can take hundreds of amps.
I understand that, but what I don't understand is why I can't set the PS to 3.65V as an upper limit and then have the PS output 10A until it reaches that point and then safely scales down the charge to a trickle.
 
I understand that, but what I don't understand is why I can't set the PS to 3.65V as an upper limit and then have the PS output 10A until it reaches that point and then safely scales down the charge to a trickle.

That's what you did as you described it .... you just can't see it once you connect the leads and the power supply is at max amps.

You got a resolution and learned a few things along the way.
 
I understand that, but what I don't understand is why I can't set the PS to 3.65V as an upper limit and then have the PS output 10A until it reaches that point and then safely scales down the charge to a trickle.
That is what will happen if you follow the directions. Honestly. It will just take a LONG time depending on how empty your batteries are.
 
I understand that, but what I don't understand is why I can't set the PS to 3.65V as an upper limit and then have the PS output 10A until it reaches that point and then safely scales down the charge to a trickle.
V is set to 3.65 and amps to 10a and that is all you need to to do. Let it run, eventually voltage of the cells will begin to limit amps. PS is left on until amps reach almost zero.

This was a good lesson for you to learn about voltage drop. VD is in every circuit, keep this in mind when purchasing cables that carry large amp loads or loads far from the power source.
 
Set the power supply to 3.65v using your meter to measure the voltage while not connected to the cells.
Connect the power supply to the cells, observe 10 amps out, ignore displayed voltage, notice constant current LED is lit.
When voltage gets close enough, display will change to voltage, and constant voltage LED will be on.
Wasn't sure, so I set the output at the output to 3.65V which showed as 3.56V on their display.

After connecting the leads to the battery, the voltage at the PS dropped to 3.52 and the voltage at the batteries is 3.39, just like it was with the 16ga wires. I am hoping that voltage will go up as it fills the batteries?

Thanks
 
Wasn't sure, so I set the output at the output to 3.65V which showed as 3.56V on their display.

After connecting the leads to the battery, the voltage at the PS dropped to 3.52 and the voltage at the batteries is 3.39, just like it was with the 16ga wires. I am hoping that voltage will go up as it fills the batteries?

Thanks
Yes, the voltage on the cells will go up when they get full. They have an extremely flat charge curve until they get to 3.4v, above 3.45v they take off like a rocket.

In the meantime, they drag the power supply down to their level, only limited by the resistance of the wires and connections (and the 10 amp limit of the supply).

When the voltage on the cells rise enough, the amps will taper, the power supply will sit at 3.65v, and eventually the cells will reach 3.65v as well.
When the amps taper under 1, you are done.

Think of it as a water pump and a hose. The pump is capable of 3.65 PSI pressure, but is limited to 10 gallons a minute. If you fill a water tank, you set the pressure to 3.65 PSI, and if the hose is large enough, it can pump 10 gallons a minute until the water tank reaches 3.65 PSI. If the hose is too small, you can't push through 10 gallons per minute. If it is large enough, it will happily do so until the pressure is nearly equal, and the flow rate will begin to taper.
 
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Yes, the voltage on the cells will go up when they get full. They have an extremely flat charge curve until they get to 3.4v, above 3.45v they take off like a rocket.

In the meantime, they drag the power supply down to their level, only limited by the resistance of the wires and connections (and the 10 amp limit of the supply).

When the voltage on the cells rise enough, the amps will taper, the power supply will sit at 3.65v, and eventually the cells will reach 3.65v as well.
When the amps taper under 1, you are done.

Think of it as a water pump and a hose. The pump is capable of 3.65 PSI pressure, but is limited to 10 gallons a minute. If you fill a water tank, you set the pressure to 3.65 PSI, and if the hose is large enough, it can pump 10 gallons a minute until the water tank reaches 3.65 PSI. If the hose is too small, you can't push through 10 gallons per minute. If it is large enough, it will happily do so until the pressure is nearly equal, and the flow rate will begin to taper.

What I guess I wasn't clear about is where in the chain do I get the 3.65v? I thought the batteries were being charged to 3.65, but setting the PS at 3.65 doesn't give 3.65 to the batteries, right? So wouldn't the PS have to be set to something over 3.65 to get actual 3.65 in the bats?

Thanks for dealing with my ignorance.
 
What I guess I wasn't clear about is where in the chain do I get the 3.65v? I thought the batteries were being charged to 3.65, but setting the PS at 3.65 doesn't give 3.65 to the batteries, right? So wouldn't the PS have to be set to something over 3.65 to get actual 3.65 in the bats?

Thanks for dealing with my ignorance.

How charging works by @smoothJoey

The power supplies' that we use for top balancing are called cc/cv.
CC = constant current.
The power supply lowers its charge voltage below the value you configured to maintain the current(amperage) value you also configured.

CV = constant voltage
When the charger no longer has to lower the charge voltage to maintain current then cv mode is achieved.
Current flow is based on potential(voltage) difference between 2 points.
As the battery voltage converges(potential difference decreases) with the charge voltage therefore current flow approaches zero.
 
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If you set it to 3.65 before you connected it .... It will charge them to 3.65 .... It will just take a while.

When the batteries reach a higher voltage and the current drops, you will see the voltage come back up on the power supply .... patience, patience, patience is what is need now.
 
View attachment 56551

OK, I stacked the PS on top of the bank of batteries to get the PS display and all 4 connectors in the pic. My on-hand wire choices in stranded were 6 and 16ga. I chose the 16ga which is rated for 10A. You can see I put ring terminals on both end of the wire, i.e. I am not using banana plugs.

Here is where the mysterious lack of charging takes another turn.

To recap, the voltages were 3.3 from factory, 3.36 after individual cell charging, and 3.40 after 9 days charging as a bank. Guess what. After I made the changes to the wiring yesterday and charged the batteries for another day with the new wiring, the voltage DROPPED to 3.38. I checked the first and last cell in the battery bank to make sure just the last cell (used for all measurements) wasn't wonky.

The PS showed 3.65V, 1.78A and 6.5W yesterday and per the picture, it is now 1.75 and 6.4. So even though the battery bank dropped voltage, the charger is putting out even less.

I hadn't measured resistance. What two points do you want the resistance measured across? I didn't know there were any connections or wire distances involved here to get a voltage drop.

Thanks
FYI.

 
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