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

I need some electronics help...
Can I somehow wire the balance taps of two Maxamps 2S2P (with Apache/Hyperion connectors) packs to act as one 4S pack ?

I probably should like to a pin-layout of the Apace/Hyperion connector but I have only found a few in PDF's available on the net.
Also see post 24-25 in http://www.rc-monster.com/forum/show...&highlight=dpm

I cant figure out what "You just daisy chain the LVC connectors" means.

It's kinda hard to explain in words, but take a look at the bottom of this page. That should help you visualize what is meant by daisy-chaining.

If you are hesitant, I would see if you can get a cable pre-made to do what you want. If done incorrectly, you could literally burn up a balancer wire if hooked up wrong, but it depends on how you have it set up.

Just a check to see if I got it right, If I want to use a 4S capable LVC to monitor both packs of my HV-Maxx truck I should use the "Hyperion connector 2S + 2S, balance connector only"
Am I right ?
If I make a connection harness what volts should I expect to see at the pins on the connector towards my LVC ?
(I guess a voltage check would be good to to before I hook it up and fry my LVC...)

Well, on the end of the "combiner", you'd see each of the cell voltages. And from the leftmost pin to the rightmost pin, you'd see the full pack voltage.

Question: Does this LVC you plan to use monitor each cell individually? If it just monitors the full pack voltage, you can simply tap off the main power wires, just like you'd do to install a UBEC.

Its the CellPro from FMA direct http://www.fmadirect.com/detail.htm?...117&section=45

My understanding is that it should be capable of monitoring each cell but if you have the time, please verify it....

Yeah, it looks like it does monitor each cell. So, you'll need to make a balancer harness Y adaptor.

There is very little difference between my two diagrams for "2s + 2s, using main leads" and "2s + 2s, balance connector only".

Yup but with the Hv-Maxx ESC with it's two inputs I assume I only got one option (without main leads) or am I wrong ?

if you put them in series, it goes like this;

one red and black wire are unused and are considered a connection to make a 4S pack, a 2S pack uses 3 wires. one 0V/black, one 3.7 and one 7.4. between the 3.7 and 7.4 tab is a 3.7V again;

now if you put them in series for 4S, you need a total of 5 wires. and each wire differs the 3.7V of the cell. the two most outer wires measure ~18.5V.

I cant relly understand what Y connection option I should use with the Hv-Maxx (2x pack serial connection made internally in ESC).

Remeber that I wont use it for balancing the packs but for a LVC that will monitor all cells in both packs and shutdown if any cell goes low.

Should I use:
http://themax.se/E-Maxx/lvc/2s+2s=4s balancer plugs.jpg

Or:
http://themax.se/E-Maxx/lvc/2s+2s=4s main leads.jpg

You need to use picture 2 for your cell shield.

Serum and BrianG, thanks for your help.
I will use the CellPro DSM LVC but I guess the connections will be the same.
Also this is what I got from FLMdirect support:
"Here is how to wire it.

You will need our 2mm pigtail.

Pin 1 is black and should connect to your speed control black.
Pin 2 should connect to 4V Node 1.
Pin 3 should connect to Red of the lower pack. (Center tap in the speed
control)
Pin 4 should connect to 12V Node 1 on the upper pack.
Pin 5 is red and should connect to the red of the speed control (16V)

You can easily verify that you wired correctly before connected the DPM.

On the 2mm Cell Pro pigtail, you should verify the following voltages. Put
the Negative probe of your meter to speed control ground.

Pin 1 (Black) is 0V
Pin 2 (White) is 4V
Pin 3 (White) is 8V
Pin 4 (White) is 12V
Pine 5 (Red) is 16V

Once you have the pigtail reading the above voltages, plug it into the DPM
and do the setup."

Now I just need to find the connectors here in Sweden...

If your LHS doesn't have/can't order any, I found some on ebay a while back, but it was only a good buy if you got like 3 or 4 of them because of shipping.

Does the connectors have a more officiall name then Apache/Hyperion connectors ?

Not really. You might also seem that called Polyquest balance connectors, since Polyquest was the first company to use this connector.

I decided to make a drawing of how this would work with the HV-Maxx, including the internal connections that the HV-Maxx uses. I am doing this because I want to see if anybody can locate a short in the system (not saying there is one, but this will help see if there is one).

http://img.photobucket.com/albums/v1...maxxhookup.jpg

EDIT:
It works the same way with the EVX.
If someone wanted to overcome this issue, he/she could simply disable the BEC circuit, put a jumper on the non-BEC input, use a UBEC/receiver pack, and put the two main packs in series. Then, the ESC would work just like any other single-battery ESC out there.
Here's a pic of what I mean:

http://img.photobucket.com/albums/v1...ingleinput.jpg

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.

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.

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)