Common caps for two escs?

[CraigP]

Ah hah!!!!! I have been curious about this fact for awhile now but have not seen any manufacturer list specs. I would like to run a HV system but feared the ESC wouldn’t take it.

BTW guys this is a real good read. I have not experienced any of the loop issues but see room for improvement. Mmm, did lose one side of a twin ESC once mind you with no real cause

Shawn, will include you on the email traffic. If others have a serious interest in this discussion, please PM me an email and I’ll get you on the list. I think this is the best way to keep this topic going in the positive and constructive direction.

[srislash]

Shawn, will include you on the email traffic. If others have a serious interest in this discussion, please PM me an email and I’ll get you on the list. I think this is the best way to keep this topic going in the positive and constructive direction.

Thanks Craig, you know I'm all about getting things right.

[ray schrauwen]

[ATTACH=CONFIG]156293[/ATTACH]

This is more approximate. I think it could be useful.
I also followed the advice and link the ground wires of both ESCs.
[ATTACH=CONFIG]156294[/ATTACH]

Very interesting circuit. Subbed. Might send email but I'm just lurking.

[CraigP]

Very interesting circuit. Subbed. Might send email but I'm just lurking.

Would love to put you on the copy list Ray! Just posted an updated schematic for dual setups that addresses this ground loop or noise issue, whichever you prefer to call it.

[Jesse J]

Shawn, will include you on the email traffic. If others have a serious interest in this discussion, please PM me an email and I’ll get you on the list. I think this is the best way to keep this topic going in the positive and constructive direction.

Too bad you got your feelings hurt even after I explained that I was NOT ridiculing you. The hobby is not worth getting all stressed out about.
I'd like to learn, but not at the expense of tangling over misunderstandings.

[CraigP]

Hmmm, you might want to read what you posted over again. It’s easy to say I’m a snowflake that gets feelings hurt easily. Actually, thought you might want to know, received a PM from another forum member asking if I had done something to upset you. Seems I’m not the only one that didn’t get what meaning you were trying to convey. Some of us are serious about stopping unexplained failures and achieving extremely reliable boats. Sorry we got off track, but you posting about this being all my problem tells me you have other things on your mind. I wish you the best sir and I still enjoy and learn from most of your posts.

[TRUCKPULL]

Shawn, will include you on the email traffic. If others have a serious interest in this discussion, please PM me an email and I’ll get you on the list. I think this is the best way to keep this topic going in the positive and constructive direction.

Why take this to a private conversation?
There are probably a lot of us here on the forum including me that are interested in reading this discussion.

I run a duel motor cat with two ESC's
Red wires disconnected on both ESC's
U-BEC for power to the receiver.

Also both ESC's wired together on the battery side (+ and -) so each ESC sees the 6S2P setup.

Larry

[CraigP]

Can I ask you a question? Do your ESC’s have Internal BEC’s in them?

[TRUCKPULL]

Can I ask you a question? Do your ESC’s have Internal BEC’s in them?

YES


Larry

[CraigP]

Well Larry, we are discussing the problems encountered when running that exact configuration. So this schematic that’s being discussed is really different than your configuration. I’d expect you’re happy with your setup, but are you interested in reading about the potential problems? Before we went off site, it was discussed how running your batts and cap banks in direct wired parallel can create a lot of added stress on the caps, which are already stressed pretty good at these amp levels. The two motors don’t run exactly the same, so the caps see some really high current surges as the motors beat frequency to each other. That was the reason for posting the 3-terminal cap schematic earlier in the thread. Do you see any validity in what I’m saying?

[TRUCKPULL]

Yes the schematic in post #7 is what really me interested in this topic.

For my setup of 6S2P - would the connections for the 2P be before the cap bank or after the cap bank?
Two black going into the ESC's joined together, and the two red going into the ESC's joined together.

I race my boats, what I have noticed in the past before I started running the 2P setup is that towards the end of a race, on the last couple of laps the boat
would start to pull to the left down the straightaways.

Seeing that the hull is a CAT, in the turns (right hand) the outside prop is pushed down into the water more then the inside prop.
So as the race goes on the outside battery is getting run down more then the inside battery, causing the left hand pull.

Larry

[Jesse J]

Larry I noticed that the outside motor really draws more mah, 10-20% more! And exactly why I started this thread. Sincere thanks to all!

So I am thinking this as my plan.
This schematic should satisfy all participants in this thread.
If not please speak up.

[TRUCKPULL]

Jesse

Your schematic is exactly what I have now.
I like the cap bank that Craig posted in Post #7
Put now am getting confused, as he says NOT to connect the two red Battery wires together.

This means NO 2P setup.
This does NOT work for me when Racing. ( I need the 2P setup)

I can see it now I come out of the last turn, my boat stars to drift to the left. The guy right behind me passes me for the WIN on the inside.

Or I drift out an take out an other boat, CD calls me DQed for not holding my lane, now between the two boats there is over $2,000.00 in damage.


Larry

[CraigP]

This is a tough problem. I can surely see that one batt pack may get less volts on it at the end of the run. Also, I was planning on putting in a small PCB mixing board, that will slow the in-bound motor under steering command and make it turn better, but that will cause differential battery drain as well, especially on a novel course. I’ve read some racers like the transmitters with channel mixing, but they are a bit pricey. There’s a solution here, and I’m interested in exploring it because my boat may show the same problem. The 3-terminal cap solves the excessive ripple problem (well even under single ESC systems, the cap takes it on the nose). Larry, if you give me a bit of time on the CAD, I think I can come up with something that gets the noise out of the control system while allowing for dual battery pack connection. I’ll post something here tonight, but I’ve got to run some calculations. I’ve got an electrical simulator that can give me a pretty good idea on how it will work. Probably get simulation results tomorrow. This is a good one, I like it!

[CraigP]

Larry I noticed that the outside motor really draws more mah, 10-20% more! And exactly why I started this thread. Sincere thanks to all!

So I am thinking this as my plan.
This schematic should satisfy all participants in this thread.
If not please speak up.

Yes Jesse, that’s the power connections, and that’s the direction it’s got to go to fix the asymmetrical battery drain. But the “problem” comes with the interaction of the control hook up with the battery connections. Jesse, does your ESC’s in the dual have internal BEC’s like Larry’s setup?