John

2s 18650 discussion

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Well like I said from the photo it looks like you have pin 3 connected to positive 8.4V instead of the pin 2 (like shown in the wiring diagram earlier). Or "the tap connection labelled 3 must be connected directly to the tap connection labelled 2" in the OP.

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Dejay said:

Well like I said from the photo it looks like you have pin 3 connected to positive 8.4V instead of the pin 2 (like shown in the wiring diagram earlier). Or "the tap connection labelled 3 must be connected directly to the tap connection labelled 2" in the OP.



I tried it the other way and the board wont even start. 2 and 3 are together on the positive.

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Hmm just in case of misunderstanding: I think 2 and 3 should be together on the middle between both cells (3.7V) and not on the postive (8.4V)

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Well that still looks wrong. Try removing the top white cable and splice it with the one coming from the bottom (3.7V). Or have another look at the wiring diagram posted on the last page.

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Dejay said:

Hmm just in case of misunderstanding: I think 2 and 3 should be together on the middle between both cells (3.7V) and not on the postive (8.4V)



So you are saying 1 should be on the positive and 2/3 should be on the bridge?

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Dejay said:

Well that still looks wrong. Try removing the top white cable and splice it with the one coming from the bottom (3.7V). Or have another look at the wiring diagram posted on the last page.



That's what I did try. Board won't boot.

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So you are saying 1 should be on the positive and 2/3 should be on the bridge?



Yes that's what I understand is the correct way. But I haven't done it either. Oh well.

Maybe someone else can comment on the wiring.

Or maybe it's the wrong way around? (wrong polarity?)

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Take #2,#3 and connect it to the B+ That's how I under stand it and plan on doing it that way

image.jpg

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Laguz75 said:

Take #2,#3 and connect it to the B+ That's how I under stand it and plan on doing it that way



That's what I did. Almost seems like the board doesn't like 8.4v.

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So you wired it as described by John in Post #1 here and it doesn't work?  Maybe John will drop by this thread as he has time.

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dc601 said:

So you wired it as described by John in Post #1 here and it doesn't work?  Maybe John will drop by this thread as he has time.



At least as I understand it needing to be wired. 

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RickAdair said:

[QUOTE=Laguz75]Take #2,#3 and connect it to the B+ That's how I under stand it and plan on doing it that way



That's what I did. Almost seems like the board doesn't like 8.4v.[/QUOTE]yeah I can't really help you any more cuz by board is still in the packaging box. John did say this way seems to work.

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Rick, I think that everything's fine with your wiring, let the gurus chip in and confirm. John, can you please check this last 10 posts and advice what could be Rick's problem?

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That's wired properly. The question is why you're seeing .6 volts on cell 3. 

It won't fire as a 2 cell unless it is reading less than .1 volts. SO that's the problem. 

I'll post a picture of my extremely hacked together 2s tapped battery box (made from a hana battery box, a vaporshark battery box and a lot of hot glue) in a bit. 

I did jump the connection right at the tap connector, rather than running two wires all the way back to the battery, but that shouldn't make that much of a difference. Obviously it is getting the two cell voltages that are actually there correct.

Its either some sort of subtle wiring difference or we just need to widen out what it will call "no cell" in the firmware. 


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John said:

That's wired properly. The question is why you're seeing .6 volts on cell 3. 

It won't fire as a 2 cell unless it is reading less than .1 volts. SO that's the problem. 

I'll post a picture of my extremely hacked together 2s tapped battery box (made from a hana battery box, a vaporshark battery box and a lot of hot glue) in a bit. 

I did jump the connection right at the tap connector, rather than running two wires all the way back to the battery, but that shouldn't make that much of a difference. Obviously it is getting the two cell voltages that are actually there correct.

Its either some sort of subtle wiring difference or we just need to widen out what it will call "no cell" in the firmware. 




Thanks John. I did try shorting 3 at the female side of the jst and it didn't help.

I'm trying to keep this setup so that I can plug in Lipo or 2cell so I really don't want to short it board side.

Thanks again!

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Oh no, I didn't do it board side. I did it on the tap connector on the pack side. Mine switches between 2s and 3s just fine and shows .02V on cell 3, but that could just be mine for all I know. I'll try a couple more boards today and see if I can get the same one cell high behavior. 

The reason it looks at cell 3 at all is we don't want to get people into a bad situation if they should just happen to plug a 3s battery with a damaged third cell into the board with it set for 2s. But where the cutoff should be is going to be a function of where all the boards read the phantom cell. 

We'll get you working one way or another.

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