How I topped off a new set of lith's fast.

[Bossrox]

After the pack was balanced, I set my charger to 27.6v which is about 3.45v & is about the knee wall of a pack that's close to fully charged. Longevity of lith's is reportedly determined by limiting the discharge depth & the upper voltage.

Those who may not be familiar with the term knee wall, it's the cliff points where lith's voltage will either fall or rise sharply. I think the low point is somewhere around 3.0v.

 

[sunshine_eggo]

You didn't follow Will's advice. Will's way is to initially charge in series with the BMS active, then parallel them.

Top Balancing LiFePo4 Cells using a low cost benchtop power supply.

To get the paper, click on the orange at the top of this page. This is a tutorial with detailed steps on how I top-balance my LiFePO4 Cells using a low-cost benchtop power supply. To get the tutorial, click on the orange "Download" button...

diysolarforum.com

 

[Bossrox]

You didn't follow Will's advice. Will's way is to initially charge in series with the BMS active, then parallel them.

Top Balancing LiFePo4 Cells using a low cost benchtop power supply.

To get the paper, click on the orange at the top of this page. This is a tutorial with detailed steps on how I top-balance my LiFePO4 Cells using a low-cost benchtop power supply. To get the tutorial, click on the orange "Download" button...

diysolarforum.com

The video I saw on Will doing a top off was all cells in parallel, I didn't see anything like you're mentioning but that sounds like a smart alternative as well. I hadn't thought of doing it that way, getting them close in a series charge & finishing them in parallel makes good sense for a speedier way to do it.