I have been using a simple charging cable that simply connects all 1S batteries in parallel as one big 1S pack. This way is very slow and requires all packs to have very close voltage.
Here I will show you how I made a charging cable that can allow me to charge the 1S lipo much faster.
Depending on how many lipos you want to charge per turn, as an example, I want to charge 4 packs every time, so I use 4 connectors on my cable. With this cable, I will be able to charge the Batteries as one single pack of 4S Lipo.
You can also use 5 connectors and make it a 5S, or 6 connectors as a 6S if you charger support charging this high voltage. It only means you can charge more batteries at the same time.
Instead of connecting the packs in parallel, we connect them in series, and the cable wiring basically looks like this.
However, the batteries have to be the same type, same brand, same capacity. You might be able to get away from these, but It's not safe. As for voltages, a few times some of the packs voltages were quite far apart like 3.4V and 3.7V but it charged just fine. I heard some chargers don't charge if cell voltages are too far apart so just bear in mind. However charging will take longer if the cells voltages are too different, because it takes time to balance them internally. Therefore always charge lipos at similar voltage level.
When charging, just select "Balance Charge" on your charger (it should require the big discharge lead and balance plug)
Also I wouldn't recommend charging it exceeding 1C. For example i have 4 x 200mAh 1S, when connected with the cable they become a single 200mAh 4S. So I would want to charge it at 0.2A current.
I am using 2 different types of connector for each branch
So it can work with Tiny whoop batteries ( Pico blade) as well as the Lossi connectors.
(Both XT60 and 4S balance plug are recycled from a dead 4S lipo)