Mixing Lipo Batteries to make 5s, Will these work together?

[Drax21]

DSC_0763.jpgDSC_0764.jpg
2 batteries both can be seen in pics.
1 is a Turnigy(B Grade Battery) 40-50c 5000Mah 3s
the other is a Turnigy Hard Case 40-50c 5000mah 2s

I wanted to run 5s in my pursuit but don't know if its too dangerous to combine batteries which have different internal resistance.
The B grade battery does not balance well and has been used about 3 times, gives good performance though.
The 2s Hard case has not been used yet and balanced perfectly.
Let me know what you would do.
Thanks

[Fluid]

I would be very hesitant to use both packs, particularly if you were to draw them down near the LVC. Even if they were identical in every other way, using one pack which does not balance well is asking for trouble.


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[Drax21]

Thanks for quick reply, as I thought, it is a bit risky. 1 cell on the 3s pack always goes red before the others(on Lipo protectors) Guess I got some new batteries to buy...