Feedback on my noob setup

I'll be running four 5000mah 5S packs in 10S2P for 37v 10ah. Upper and lower packs are paralleled at discharge and balance leads with Andersons in custom harnesses.

For charging, using 1010B, the parallel harness is removed from the discharge leads, and the charger connection places a pair of packs in series to charge 10S. The balance leads are split, and connected via custom harness to the balance port. I've got both negative leads for the balance cables still in parallel during charging. Is that the right way to configure the balance leads for 10S charging?
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I figure this setup is useful, as I can check individual cells at any time just by pulling the plugs. I think this also allows me to bulk charge the entire pack as 10S2P, as long as I don't hook up the balance leads.

I have almost the exact same setup as you do. Same 1010B charger and all. The only difference is that I don't use my lipo balancing leads at all when using the discharge harness and I don't bond the two negative balancing leads together when using my charging harness.

I have used my harnesses for a while this way and they seem to work well although yours should work well too. In fact your two lipo pairs should stay more in balance with each other. I'm still kind of a noob at this too but, maybe someone else will chime in if they see a problem.

Thats a very nice setup, and would work fine.

But I don't do it that way, and here's why. When a lipo cell goes bad, its usualy caught on the charge cycle. If you're running the cells parralleled through the balance taps, the bad cell may be pared with a good cell, keeping the voltage on the bad cell from changing as much as it normaly would. That means the badd cell will be harder to find, and the good cell it was pared with will show the same final voltage, so it will be difficult to tell which cell was the problem. One may go boom, and the other will be fine. which one do you want to charge?

The benifit of the 1st diagram is you wouldn't need balance as often, maybe. But the problem is balancing is where you catch problems before they become bigger problems when you're not running a BMS so you should be balance charging almost every time anyway.

Yikes!! Just realized that my charging diagram has a major error. The two negative leads at the balance taps SHOULD NOT be paralleled.
Since the packs are in series for charging, that makes the 5 tap on the upper pack electrically the same as the negative tap on the lower pack.
My original diagram would have placed a short across the positive and negative leads of the upper pack!!
Here's the corrected diagram:View attachment Schematic-Charging.JPG

can i ask what program you used to draw that diagram?

Also, why rewire to charge only two packs at a time at 10s? you're running 10s 2p and you're rewiring to charge 10s1p? If you permanently parallel the two batts together to get two 5s2p won't you end up with two 10 ah 5s blocks that will balance as one, which can then be charged in series as 10s2p?

For instance, I am executing a 24s3p build now. I will have 4 3 battery blocks in the end; each 22v 15ah for 6s3p. Then i will series them together to form a 24s3p battery. Each block will be balanced as a 6s3p block, each cell will be paralleled to it's block-mates.

I just think that your set up has a lot of plugging and unplugging and that is typically what you want to avoid in the lipo charging arena because plasma seems to have resulted more often then not, even with the experts, from forgetting to either series/parallel their balance leads when charging or discharging.

Andje,
I used MS Visio for the diagrams. It's on my work computer. At home, I use OpenOffice Draw. If you google Visio freeware, you'll find many free programs that can do these diagrams.

I'm setting up this way so I can balance at the cell level, not paralleled cells. I agree, it's a lot of plugging/unplugging, but, I'm going slowly here with my first batch of lipo. If the cells stay balanced, and the plugs become a nuisance, I'll probably solder the pack together.

...but if you keep them permanently paralleled, they will be balanced with eachother, that's the effect of keeping them parallel.

bjosta said:

...but if you keep them permanently paralleled, they will be balanced with eachother, that's the effect of keeping them parallel.

Click to expand...

yup.

I have a similar setup. The only hitch is that the parallel leads need to be connected in the correct order or you will fry a balance board and a balance connector pin too... found that out the hard way

Will be running 4x 5ah 5S packs.. serial harnesses on each pack, connected to a parallel harness. This is so that i can take out a set of 2 batteries if i suspect something is wrong.

As for the balance leads, they run to two 4x splitters.

When i go to balance charge, it will be like plugging in one pack of two 5ah bricks serialled together; one charge discharge lead, and two balance leads.

I only worry if the voltages look disbalanced on a cell group.

Thought more about all your comments, and came up with a new set-up that permanently parallels the the discharge and balance leads with harnesses, but still allows easy separation for pack replacement or troubleshooting. Now, no unplugging to charge.
The balance harness is split into 3x four connector groups to allow them to be stacked together.
I'm also going to add a fuse holder at the series connection between to the upper and lower packs.