15s 15aH?

sacko · Jul 30, 2012

Is this correct?

In either 'stack' there is;
2 x 6s 5000
1 x 3s 5000

Each stack is then made in parallel, then both parallel leads are put in series (at the controller)

electr0n · Jul 30, 2012

I think you may have that wrong. I don't think you can parallel a 6s with a 3s. You'll create a short and current will flow from the 6s to the 3s to try and equalize. When you parallel packs they should be the same voltage.

You could connect them in series first then parallel. 6s + 6s +3s in series to make 15s 5 amp hours for each stack would give you 15s 10 amp hours.

sacko · Jul 30, 2012

That makes more sense, didn't think it looked right.

Cheers

electr0n · Jul 30, 2012

You could also parallel 6s + 6s, 6s + 6s, 3s + 3s then connect those 3 pairs in series if you prefer to parallel first then series. The series first method is the simplest and has the least wiring.

Ykick · Jul 30, 2012

electr0n said:
You could also parallel 6s + 6s, 6s + 6s, 3s + 3s then connect those 3 pairs in series if you prefer to parallel first then series. The series first method is the simplest and has the least wiring.

Exactly, OP has 4qty 6S and 2qty 3S bricks. Most capacity for 15S is 10Ah and remember that is pushing it.

I do series groups 1st and then just parallel whatever desire for capacity. 2P, 3P, 4P, 10-20Ah.

Parallel 1st is ideal if dealing with all same bricks but that's obviously not the case here. No problem series wiring 6+6+3=15...

wesnewell · Jul 30, 2012

Each stack is 15s 5ah, so it's 15s2p for 10ah. But you've really complicated it with lots of unnecessary main wiring and no parallel wiring of balance cables (optional, but good idea imo).

sacko · Jul 30, 2012

The wiring is necessary as the packs have other uses (rc Heli).

I'll be using the Cellpro MPA board to parallel charge on my PL6. The board has re-settable polyfuses etc for safer charging, hence there being no need for parallel balance leads, just 6" extensions.

Sacman · Jul 30, 2012

Ykick said:
Exactly, OP has 4qty 6S and 2qty 3S bricks. Most capacity for 15S is 10Ah and remember that is pushing it.

I do series groups 1st and then just parallel whatever desire for capacity. 2P, 3P, 4P, 10-20Ah.

Parallel 1st is ideal if dealing with all same bricks but that's obviously not the case here. No problem series wiring 6+6+3=15...

I know the OP doesn't have a 15s charger... so for discharging doesn't make much of a difference whether you parallel 1st or series 1st. But for charging (especially if you're bulk charging) parallel 1st is better since you'll only need to break half the connections to charge. And you can charge each group at a full 10Ah rather than separate bricks at onlh 5Ah.

Ykick · Jul 30, 2012

Sacman said:
Ykick said:

Exactly, OP has 4qty 6S and 2qty 3S bricks. Most capacity for 15S is 10Ah and remember that is pushing it.

I do series groups 1st and then just parallel whatever desire for capacity. 2P, 3P, 4P, 10-20Ah.

Parallel 1st is ideal if dealing with all same bricks but that's obviously not the case here. No problem series wiring 6+6+3=15...

Click to expand...

I know the OP doesn't have a 15s charger... so for discharging doesn't make much of a difference whether you parallel 1st or series 1st. But for charging (especially if you're bulk charging) parallel 1st is better since you'll only need to break half the connections to charge. And you can charge each group at a full 10Ah rather than separate bricks at onlh 5Ah.

Works if you ride only every once in a while but daily use and they'll start looking for a 62V supply to serial bulk charge. Why break any connections on a regular basis? Parallel business is just goofy and introduces way too many connections and possibilities for potential connector failure IMO. Using tested bricks series wired, one connection 62V supply. RC Charger for troubleshooting, balancing work only.

amigafan2003 · Jul 30, 2012

electr0n said:
You could also parallel 6s + 6s, 6s + 6s, 3s + 3s then connect those 3 pairs in series if you prefer to parallel first then series. The series first method is the simplest and has the least wiring.

I have the exact same packs as the op and that's how I do it. The pairs of paralleled packs are also paralleled at the balance taps as well.

15s 15aH?

sacko

10 kW

electr0n

1 kW

sacko

10 kW

electr0n

1 kW

Ykick

1 GW

wesnewell

100 GW

sacko

10 kW

Sacman

10 kW

Ykick

1 GW

amigafan2003

1 kW

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