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View Full Version : 4s lipo wiring on stock esc

dreher
02-14-2009, 05:17 PM
Hey guys, I will be getting my summit Monday or Tuesday (very excited). I have a few questions about plugging in my batteries. To give you an idea of where I'm coming from, I have a couple electric race boats I run with 4s batteries. I use a CC hydra 125. I use a connector on the leads of the esc so that both batteries positive leads plug into the single positive of the esc and both negative leads from the batteries plug into the single negative lead of the esc. My question is:

there are 4 wires coming out of the summits esc, but I want to run 2 4s batteries as a single 4s (doubling the mah, but keeping 14.8 volts, I forget if that is a series or parallel). So, how do I do this? I diagram would be very helpful if anyone has one :)

watrfrndlyrusty
02-14-2009, 05:53 PM
where are these batts going and it sounds like the one on the boat has paralell which is what you want but b4 doing it plug the batts in and check voltage from the one plug attached to the 2 batts

02-14-2009, 05:57 PM
If your battery pack is really 4S, each pack by itself would be 14.8V (4 cells in a row at 3.7V a cell). The Summit ESC is looking for no more than 8.4V per Traxxas plug (or pair of wires) coming from the ESC. You would have to take apart and rebuild your 4S packs to be 2 2S packs. The whole parallel and series thing has to do with how the cells are wired. Parallel means that cells are wired positive to positive and negative to negative. That doubles your mAh but keeps the volts the same. Series means that that cell goes from the positive of the first cell to the negative of the next one. Series increases your voltage but keeps the mAh the same. Here is a decent explanation of how this works. http://www.batteryuniversity.com/partone-24.htm

Besides all that, you will probably want 2 packs, to keep the Summit's weight balanced. Assuming you really want to put your 2 4S packs together as the only input to the ESC, you would need to plug them together in parallel (positive to positive and negative to negative). Then take apart the ESC and try to rewire it to take one 14.8V input instead of 2 7.2V(up to 8.4V) inputs. How to pull that off is something that I haven't the faintest clue on.

Another option is to get the Mamba Monster brushless combo (http://www.castlecreations.com/products/mamba_monster.html), which will take up to 2 6S inputs, but that is another \$300.

FireWire79
02-14-2009, 06:58 PM
Wow. Last I knew, you could run the batteries in parallel by making a parallel harness and capping the non-BEC side of the ESC. This would provide the needed voltage and preserve the stock ESC.

I would search on the E-Maxx and the E-Revo forums for more info on this, I know some one has done it.

Bandit_Kaine
02-14-2009, 09:10 PM
Wow. Last I knew, you could run the batteries in parallel by making a parallel harness and capping the non-BEC side of the ESC. This would provide the needed voltage and preserve the stock ESC.

I would search on the E-Maxx and the E-Revo forums for more info on this, I know some one has done it.

You can do it but only with lower voltages... the BEC is going to fry by seeing 14.8 volts on the BEC side... running 4s is possible by running 2s on each side.. not by running 4s on the BEC side.

dreher
02-14-2009, 11:48 PM
Thanks for the info guys, I will keep looking into it to see what I can figure out. Worst case is maybe just getting a different esc.

egnix
02-15-2009, 08:32 AM
dreher, according to the E-revo FAQ, I believe what you want to do is possible.
See this post (http://monster.traxxas.com/showpost.php?p=3606316&postcount=71)

dreher
02-15-2009, 07:16 PM
egnix,

Thats it, thanks!

akrimmel
02-15-2009, 07:46 PM
very good info on that link/