Chowderhead72

Daisy chaining a jst connector?

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Would it be possible to add an external jst connector to be used with a stand alone 3s charger? I would make the connection at the balancing ports. Essentially 2 wires on each of the 4 terminals. My battery will take a 5amp charge, I plan to charge at 3a but not lose the cell monitoring. Will this work?

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from my understanding the balance plug alone is not enough to support this kind of fast charging, to really charge at those kinds of rates the charger needs to be connected to the main battery leads as well as the balancing plug and the main high amperage charging is done through the main wires as a pack, then it is trickle balanced after the high amperage charging, but I don't know the actual limits, maybe up to 3a might be doable? the balancing leads are pretty light

I guess the second thing is weather this would backfeed into the board if done while connected to the board. how will the board deal with this I don't know

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Sure it is... Ohms law. It's actually how most small to midsize Lipo charger work. Most small to mids don't even have primary wires. I would agree that going past 5a would be a bad idea on 22awg wire but even that is well within the ampacity of even 24awg wire at 60celcius. Check out the Turnigy P403 charger. Jst only 1s-4s jst connectors only 1-5 amps. Your second point is my actual concern.

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haven't seen one that goes to 5 amps before on just the balance plug, that's cool. def sounds like a good idea as long as it's not gonna cause the packs to swell or make them a whole lot more likely to blow while charging, I was thinking of staying with the 1 amp to avoid any problems but if this is doable without much increased risk I'd like to do it too. 3amps don't sound bad, vaporshark is going 2amp on board charging, having a 3 amp or more externally plugged in quick charge would be cool, only thing is now to know weather this is ok to do with the dna200 still inline or not, switching would be more of a pita but still not too bad I guess   

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I mis-stated... It's a 3a charger not a 5a. But still it will do exactly as I had hoped. Balance 3a charging from the JST what more could you want? http://www.hobbyking.com/hobbyking/store/__58314__Turnigy_P403_LiPoly_LiFe_AC_DC_Battery_Charger.html

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ok, makes sense cause I thought the last time I looked I seen that you would need to go to the mains for 5 amps... I'd be happy with even 3 amps and may be worry less about abusing the pack at 3 amps...

one thing to be concerned about is that this quick charge plug will have voltage potential and be a possible point of shorting if it's not sealed or internal. what do you have in mind for the plug? I'd like something easily accessible, almost like a docking port but shorting is a concern 

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Now you got it,... I have the same concerns. By the looks of it I will have to make something with epoxy poured into a mold around the connector. I have searched and most of the bulkhead connections are made for a console scenario with little concern for size. I want to make something with a deans micro 4sp type connector. Looks a lot more durable and certainly more likely to stand up to the 3a use. I have already ditched the jst 90 that comes with the dna200. Seems weak. I do have deans micros to play with. For a plug I would use the deans plug with the solder point cut off and isolated on the outside. Perhaps I would pot the plug in epoxy as well and have it finish flush with the outside of the mod itself so it looks unfinished and crappy without the plug installed and aesthetically pleasing with the plug installed. ETA: yes exactly like a docking port. I will work on it along with the all SS magnetic squonk bottle interface. No more brown squonk tubes! Run a wet pipe cleaner through it and even Pluid would be gone. That concept came from Mundy, I'm just running with it.

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well the more I think about this the more I think that the backfeeding of the board shouldn't be an issue, there is already voltage potential there so I can't see more voltage from charging causing any concerns, the board polls the battery on each fire I think so it should update to the new power level no problem, I don't see any reason why this wouldn't work. I would avoid plugging in a usb at the same time, but other than that I think it should be fine

I get what you're saying with maybe mini deans but I think there still too big for something like this unless you have extra space, and they can carry way more amperage than we'd ever need for a few amps charging. I used mini deans as my main battery connections :) I'm using a pair of jst's for the balancing and there really small, I could see that working for something like this and they can be recessed a bit so shorting wouldn't be as much of an issue, although yeah def need some kind of cover for the port anyway. ideally I'm thinking a flip up door or cover that won't get lost instead of a removable piece but depends on the design I guess

 

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Deans makes a 4s micro connector for just such an occasion. I will experiment. Mine will be behind the main cover. See pics on ecf. You know the spot..... Chowda... Btw: I charged my mod from 15% to full charge in 11 minutes today. With a $25 dollar charger and the battery was no more than 5 degrees above room temp. The Turnigy A-spec nanos are awesome!

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I'm a mechanic, not an electrician, so please humor me while I ask an idiot question as the idea of charging in under 15 min has me extremely interested: So what you are doing is splicing in to the balance connector's wires somewhere along it's length to a second balance connector for fast charging, correct? And the additional current doesn'T hirt the board? If all this is so, please point me to the ecf thread so I can see this, pretty please.

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Yes I will be adding a jst connector (3s balancing port) in parallel to the battery and board. I will find out today if it actually works; it will, but the question is will it destroy the boards USB onboard charger.

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It won't hurt the onboard balance charger to charge from an external port. It will probably make your battery meter wrong for a while, though, until it charges up enough to think you swapped packs. 

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