My 40A AC to DC Bench power supply will start by outputting 40A @ 3.6V (varies depending on voltage of the actual cell) Constant Current then eventually it will flip to CC Constant Current at which time the amps pushed to cell start to drop slowly till the cell tops @ 3.65V and amps drawn trickles down to <2.0A.
Using a TekPower TP1540E as a Bench Powersupply.
TekPower TP1540E DC Adjustable Switching Power Supply 15V 40A Digital Display
You linked to a TP1560 Which is the next up from mine. Mine works well (after I opened it and plugged in a loose connector).
The dials are touchy or finicky. Turn current to full, then dial-up voltage. Note the voltage will NOT go higher than say 3.5V or so at the start, that is normal...
As the cell(s) start to fill up you will be able to tweak the voltage, ALWAYS VERIFY the output voltage at the Powersupply Terminals
and then at cell terminals, they will show different.
As Cell voltage increases, so will the output voltage on the bench supply.
Once cells reach 3.400 the voltage will start to climb fast (you are at the end of the curve) WATCH CLOSELY by Voltage checking at Cell & PS.
You will have to adjust the Voltage at this point because as the cell fills the supply will increase and it only take a few minutes to go from 3.65V to 3.8 and then 4.0 and it CAN happen quick !
As the cell reaches 3.65 and you dial it in properly so that the output at the PS is 3.65, you will see the amps taken fall down to 2.0A at which point it will really slow as it decreases further, you have reached Saturation at this point.
EAGLE EYES ON IT because it is very easy to run into overcharge.
I started by trying to top 4x280AH OMG it was painful !
I then decided to top each cell independently (much quicker) to 3.65V and drawing <2.0A.
Once all cells were "Topped" then assembled into parallel and Top Balanced at 3.65V till amps drawn fell to 1.7A.
All Cells completely balanced out and settling evenly.
The disconnected parallel to allow cells to "sit" independently, they all settle down at equivalent voltages & IR. After 7 days of "sitting" independently, all cells still match up. 3.438, 3.441, 3.439, 3.440 volts and all at 18mΩ
TIP: After you have fully charged the 1st cell and have the PS dialed to 3.65 (which you can do once the cell is top[ping), LEAVE IT ALONE !
!! Verify that it is at 3.60 to 3.65 at the Powersupply terminals & at the cell terminals with a DMM / DVOM !!
Then just connect the next cell to charge, turn on PS and it will show a Lower Voltage THAT IS OK ! It is looking at target cell voltage and it steps itself down to deal with it, it will do that in CV & CC modes. Just wait, as the cell starts to reach 80% + SOC (over 3.4V) you will see the PS increase the voltage number on the display.
NOTE: The display on the TelkPower may read as 3.7 but output will be 3.65 Always read the Voltage with a DMM at the output terminals on the PS. The dial is very sensitive and the LCD resolution is a tad "soft".
Hope it Helps.
PS, PATIENCE is Important. a single 280AH cell from 2.50 to 3.65 takes about 13 hours with my 15/40 charger.
4 cells in parallel (linked by busbar) will quadruple the time...
(Patience Testing)