Combine balance taps for 2x 2S2P as one 4S

[BrianG]

The first pic would cause problems. The "ground" point from the BEC feeding the LVC is floating at 1/2 total battery voltage. Since the LVC sees the whole pack voltage, it might totally short out "battery 2", unless the balancer inputs were isolated somehow from the rest of the LVC circuit.

The second pic looks like it would overcome this issue since all ground references are at an equal level.

[miniGranis]

Originally Posted by BrianG

The first pic would cause problems. The "ground" point from the BEC feeding the LVC is floating at 1/2 total battery voltage. Since the LVC sees the whole pack voltage, it might totally short out "battery 2", unless the balancer inputs were isolated somehow from the rest of the LVC circuit.

The second pic looks like it would overcome this issue since all ground references are at an equal level.

Sorry all for beeing such a noob at this, BrianG are you refering to the pics in MetalMan's post #15 or mine (with your pics) #9 ?
What pic in what post would work with the Hv-Maxx ?
If possible I would like to keep the Hv-Maxx connections intact and use the internal BEC, otherwise I will just monitor the BEC side as a 2S pack.

Monitoring all cells would be better since I might not always charge both packs to its full capacity and if I then mixup BEC side and non BEC side I might go lower then whats recomended on the non BEC side since that wouldnt be monitored.

[BrianG]

Sorry about that; I meant MetalMans pics. MM's second picture looks like it would work much better, and the hookup is more like a "regular" ESC. If you look at his second pic, you see that he is disabling the internal BEC and adding an external one. This is much better because both packs are discharged the same amount from the BEC, so chances of an imbalance are less. Not to mention greater efficiency by using a switching BEC.

Im my experience, if you set the LVC to 3.2v/cell cutoff (providing that the LVC is programmable that way), monitoring each cell is redundant. This high cutoff value helps to ensure that no single cells will get too low - even if one of the cells is 0.2v lower than the rest, it is still at the 3v mark.

[miniGranis]

To me rewireing my Hv-Maxx as per MetalMans second pic is too much, one reason for me to go with Hv-Maxx was the "plug and play" concept, also I dont have an UBEC either.
I appreciate all the help, you are all very kind to us new guys.
For now I will just use the CellPro to monitor the BEC side as one 2S pack and see were that takes me. I dont want to risk damaging my LiPo's, CellPro or ESC at this moment. (I have already invested in 2x Li-Savers that doesnt work for me)