I am a new knucklehead with a question

[ClearwaterMexico]

I have 4 lifepo4 280 amp hour cells in series, they arrived all equally charged about 3.3 volts. I let them sit in series for a few days and connected a DC Power Supply set at 3.65 volts to the bank of 4 batteries still in series. after 18 hours, the batteries are still at 3.3 volts, the power supply's amps went down, I thought this process was talking too long so I discounted the dc power supply.

The batteries still read 3.3 volts...

WHAT AM I DOING WRONG????

 

[Bud Martin]

I have 4 lifepo4 280 amp hour cells in series, they arrived all equally charged about 3.3 volts. I let them sit in series for a few days and connected a DC Power Supply set at 3.65 volts to the bank of 4 batteries still in series. after 18 hours, the batteries are still at 3.3 volts, the power supply's amps went down, I thought this process was talking too long so I discounted the dc power supply.

The batteries still read 3.3 volts...

WHAT AM I DOING WRONG????

Do you really mean 'parallel'?
Four 3.3V batteries connected in series = 13.2V, so if you connect power source of of 3.65V to the 13.2V battery bank, nothing will happen.
Please show us the pictures of your setup and the wires you are using for wiring.

 

[ClearwaterMexico]

Sorry...yes i meant parallel....
plus to plus to plus to plus
negative to negative to negative to negative.

 

[Bud Martin]

We need to see the pictures of the power supply and power supply cables to the batteries.
Are you using the cables supplied with the power supply? They are junk cables.
I do not know how much current you are seeing during charging, trying to charge four 280Ah batteries in parallel will take days.
Lets us see the pictures of your setup.

 

[time2roll]

How many amps going in? 280 x 4 = 1120 amp hours. Maybe 40% charged or down 672 amp hours. Could be more.
10 amps will be 68 hours.
5 amps 135 hours
2 amps 336 hours or two full weeks. May as well get back on it.

 

[Lt.Dan]

18 hours is definitely not long enough. Its common to put the cells in series with a bms, to make a battery, and then charge with a larger, faster charger. Once a cell hits HVD, you put them back into parallel and finish it off.

 

[ClearwaterMexico]

thank u all.....thanks for the math

yes new 10 awg cables and connectors.


NEED MORE TIME>

 

[tsunami3775]

thank u all.....thanks for the math

yes new 10 awg cables and connectors.


NEED MORE TIME>

I’m at this step in my build. How did your battery turn out?