# universal charging cradle prototype with individual ballance taps



## Data (Mar 24, 2009)

The two female banana plug sockets directly behind each battery are both internally connected to their respective lower spring battery terminal. There are two extra paired banana plug sockets on each end for utility. Note that each upper battery terminal is wired to the next adjacent battery.

The clamps I used are craftsman but any kind would do. HF has them for under $2 each. The female banana plug sockets are about $1.00 each on ebay. Banana plugs are on ebay too (you just can't buy these things in a local store and get a good price).


















Cheers
Dave


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## VidPro (Mar 24, 2009)

cool, lots of access for meter reading them too. where did you get the bottom springey thing?


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## Data (Mar 24, 2009)

I made them out of some brass I had. I was going to just get some brass screws at the hardware store but it was Sunday evening and I wanted it done right then.


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## VidPro (Mar 24, 2009)

holy cow you got a computerised lathe, now how do we do it with a bench grinder a band saw and a drill, and some sandpaper


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## Data (Mar 24, 2009)

VidPro said:


> holy cow you got a computerised lathe, now how do we do it with a bench grinder a band saw and a drill, and some sandpaper



I am sorry about that.  

It sure wouldn't hurt to have a drill press to make this rig, but other than that, just the basics are all you really need.


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## karlthev (Mar 24, 2009)

Yeah sure Dave..betcha whipped up this little beauty while you were waitin' for the coffee to perk huh? :devil: Lordy but that is a nice looking charging cradle! Ya know, this could take a first place as a Christmas decoration as well! Nice Dave, real nice! I'm impressed....this uh, charges batteries too... right?



Karl


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## Russel (Mar 24, 2009)

Very nice!

Considering the size of the cells, wouldn't the C10 balance leads provide enough charge current, 1A IIRC, without using the banana jack lead connections to the cells in series on the C10? 

I take it that the brass contact has a threaded end that threads into a drilled and tapped hole in the plastic jaw?


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## Data (Mar 25, 2009)

Russel said:


> Very nice!
> 
> Considering the size of the cells, wouldn't the C10 balance leads provide enough charge current, 1A IIRC, without using the banana jack lead connections to the cells in series on the C10?
> 
> I take it that the brass contact has a threaded end that threads into a drilled and tapped hole in the plastic jaw?



For the Sony cells, you are correct, the balance wires would cover it. I also set up the rig for my M1 cells. I have over 150 of those and I need to charge them at a full 10A. The setup is easy to plug together any way I need it and into any charger I want to use.

Your suggestion would have been a good way to attach to the plastic but I just used glue. I tried to rip one apart and could not do it.

There are so many ways to skin this cat. I will say this, the springs really help. Holding the battery in place, I just slide the clamp down without even squeezing the lever.


Cheers
Dave


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## Data (Mar 25, 2009)

karlthev said:


> Yeah sure Dave..betcha whipped up this little beauty while you were waitin' for the coffee to perk huh? :devil: Lordy but that is a nice looking charging cradle! Ya know, this could take a first place as a Christmas decoration as well! Nice Dave, real nice! I'm impressed....this uh, charges batteries too... right?
> 
> 
> 
> Karl



LOL, it does need some flashing lights.


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## Russel (Mar 25, 2009)

Data said:


> For the Sony cells, you are correct, the balance wires would cover it. I also set up the rig for my M1 cells. I have over 150 of those and I need to charge them at a full 10A. The setup is easy to plug together any way I need it and into any charger I want to use.



That makes sense. I should have assumed that that the batteries in the photo were not the only size you have...especially considering this forum and all the RC stuff in the background!



Data said:


> Your suggestion would have been a good way to attach to the plastic but I just used glue. I tried to rip one apart and could not do it.



I made a quick and dirty for discharging cells with a CBA II and used hot glue. I works but not very fancy.







Data said:


> There are so many ways to skin this cat. I will say this, the springs really help. Holding the battery in place, I just slide the clamp down without even squeezing the lever.



The spring, I must say, is a great idea. When I made the quick and dirty I loaded up lots of hot glue and clamped 1" square stock to set the hot glue with the copper plates as parallel with each other as possible. I works well, but you do have to have a little tension to hold the battery. As soon as you touch the release the battery falls out. I like your idea with the spring. Soon as I get some time to play with my Sherline lathe I'm going to have to make some contacts with a spring on one side and a threads to thread it into the clamp. 

Russ


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## Data (Mar 25, 2009)

Russel said:


> That makes sense. I should have assumed that that the batteries in the photo were not the only size you have...especially considering this forum and all the RC stuff in the background!
> 
> 
> 
> ...




Those "Quick-Grip" clamps work even better than the Craftsman ones I got. The quick-grip is smoother and has a smaller "step". 

I also use the M1 cells in the Data Bank 70.

Cheers
Dave


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## Russel (Mar 25, 2009)

Data said:


> I also use the M1 cells in the Data Bank 70.



Wow! A battery powered LED version of the solar death ray! I'm very impressed!

Russ


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## LuxLuthor (Mar 26, 2009)

Very creative and perfectly functional design, Data. Bravo!


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## milkyspit (Mar 26, 2009)

Dave, that looks like some sort of portable little pipe organ! Very impressive... and who knew you could charge batteries with the thing, too? 

Hope you're bringing it to PF12... I'd like to have a look up close and personal! :naughty:


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## Data (Mar 26, 2009)

Thanks guys.

I have charged about 130 batteries in the last 3 days on it and it is functioning very well. 

I plugged in the PC interface to the Cellpro, it works well. With it I was able to input real names for the presets. And it simultaneously shows all 10 battery voltages updating real time with the current going to each battery (they were all different). Fun to watch but not really useful I guess.

I am so looking forward to PF12. I will probably bring Mike again, he got hooked on all the fun stuff we did at PF11 and he is not even a flashlight nut . . . yet.  


Cheers
Dave


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## LuxLuthor (Mar 26, 2009)

I have balance charged 12s cells using:



 3 x Voltcraft cradles
 12AWG Red/Black power supply leads
 16AWG interconnecting wires with plugs joining 3 cradles
 20AWG balance leads going into Anderson PowerPole connectors
 22AWG from PowerPoles to 2 x JST 7 pin balance connectors
 Hyperion 1210i
 2 x Hyperion LBA-10 6s Balancers
 LBA-10 Network interface connector to marry two LBA-10 6s units
 
Verifying that from terminal to final JST connection has close to the same wire length/thickness milliohm resistance.

Once it was setup, using it is very quick, and can be adapted for 2s to 11s by using/ignoring unused leads going to PowerPole, and/or disconnecting 1 or 2 cradle(s) from others. The LBA-10's can also be used to balance equalize all cells even if not using charger. They bleed off high voltage tap cells to equal lowest cell.


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## rizky_p (Mar 27, 2009)

holy, that is a HUGE charging cradle.  I wish i had a table large enough.


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## donn_ (Mar 30, 2009)

:goodjob:

Color me green with envy!:green:

Any chance of a photo of the bottom of the rig?

I sure wish someone would come up with a marketable solution to this. I'm running around 6 dozen A123s now, and making do with two 2-place Joe Chargers.


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## Data (Mar 30, 2009)

donn_ said:


> :goodjob:
> 
> Color me green with envy!:green:
> 
> ...



Donn,

Each bottom battery contact is wired straight to the two banana plug sockets that are in-line with it. I cut the wood out on my mill because it was easy but it would be easy to build this up out of some thin plywood and build a boxed in bottom for it. Those banana plug sockets need a 0.2" thick board to go through. You can get away with 1/4" plywood and counter sink it just a tad where the nut goes on.

For the bottom battery contact a 1/4" brass screw with a spring soldered to it would work good.






This is what the PC interface software looks like. It shows all battery voltages and charging currents.







Cheers
Dave


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## donn_ (Mar 31, 2009)

:twothumbs :thanks: Looks like a row of commas.

Is there a reason, other than artistic, for the curved wire channels?

If you decide you want to build a newer and better model, I'd happily buy this one.


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## csshih (Mar 31, 2009)

I wonder what would happen if you put the batteries on backwards?

I'm the sort of person to do that.


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## Data (Mar 31, 2009)

donn_ said:


> :twothumbs :thanks: Looks like a row of commas.
> 
> Is there a reason, other than artistic, for the curved wire channels?
> 
> If you decide you want to build a newer and better model, I'd happily buy this one.



The cuts curve around the wood that is holding the clamp. 

Thanks for the offer, I will keep it in mind. There are many SPY projects cooking right now and I have little extra time.

Cheers
Dave


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## Russel (Mar 31, 2009)

donn_ said:


> :twothumbs :thanks: Looks like a row of commas.
> 
> Is there a reason, other than artistic, for the curved wire channels?
> 
> If you decide you want to build a newer and better model, I'd happily buy this one.



It looks to me like the hole for the clamp mount is directly between the negative battery contact and the banana jacks. I think the groove curves around the clamp mount.


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## Data (Mar 31, 2009)

LuxLuthor said:


> I have balance charged 12s cells using:
> 
> 
> 
> ...



That is a nice setup. 

It is nice how quick charging a hundred cells goes when you are charging 10 at a time.


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## Data (Mar 31, 2009)

Russel said:


> It looks to me like the hole for the clamp mount is directly between the negative battery contact and the banana jacks. I think the grove curves around the clamp mount.




Yup, and if you were to make one of these with a 1/4" plate of plywood, you would want to glue small blocks of wood under the spots where you are drilling those holes.


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## Russel (Mar 31, 2009)

Data said:


> The cuts curve around the wood that is holding the clamp.
> 
> Thanks for the offer, I will keep it in mind. There are many SPY projects cooking right now and I have little extra time.
> 
> ...



You beat me to it! 

I have to admit the curved groove does look nice!


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## Turbo Guy (Apr 8, 2009)

Data thanks for posting this setup. 

While I have choosen a much simplier setup using magnets for connections to the cells it prompted me to try using my Cell Pro 10 charger with protected Li-ion cells and as I am sure you know it does very well, well at least it seems to as I have not charged that many cells as yet.

Several of my other hobby Chargers had a rather strong dislike of the cell's onboard protection circuits.

Thanks to a post by another member of some insulated magnatic spacers I have a stach of magnets ordered and when they arrive I will expand my setup past the single cell version I am now using.


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## karlthev (Apr 9, 2009)

I had the fortune to see this beauty in operation thanks to the hospitality of Dave and the Mrs. It's yet another admireable piece of work from one of the amazing folks on the forums! Thanks Dave!!



Karl


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## JJay03 (May 25, 2009)

Would you make something similar to sell? I need something to charge cells with my hyperion 0720i.


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## Data (May 25, 2009)

JJay03 said:


> Would you make something similar to sell? I need something to charge cells with my hyperion 0720i.



These things are a lot of labor to make but the parts can be had cheep if you are willing to shop around.

All you really need is a cheep drill press and some standard tools. 


Cheers
Dave


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## Varriano (May 26, 2009)

The charging cradle is a thing of beauty. I think there is some modesty on display however. Reminds me of my brother in law and his comments about building furniture and restoring antiques. "All you need is a decent saw and a router". Yeah and a lot of talent.

Great job.


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## Wattnot (May 26, 2009)

Nice work!

Question for the OP:

I use a Cellpro 4S with an old nicad 4 bay charger that I gutted. The 4S doesn't have a deans connection and ONLY charges the battery through the balance tap. So what I did was wire the bays so the cells are in series from the black to the red wire, then put the white taps on each of the positive terminals. If charging less than 4 I short the red wire to the positive of the last cell. Is this sort of how you are doing it? Mdocod has suggested I just charge them all in parallel and let the charger think it's all one cell . . . but that forces me to make sure the cells charge/discharge state are very close to each other. The problem I'm having is I keep getting code 17 errors. It only seems to work if the cells are at least half full and even then I get codes. I'm thinking it's because the wires might be too long and too small and the extra resistance I added is messing with the computer in the 4S charger.

Thanks!


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## Data (May 26, 2009)

Wattnot said:


> Nice work!
> 
> Question for the OP:
> 
> ...




The Cellpro engineers could tell you what is causing the error. The wires on the balance taps of my charger are a light gage too. My charger starts up with a very light charge current till it reads the battery. Does yours do that and do you get the error right away? If so it is probably not the wire size. Did you recheck the solder connections?

The 10s requires me to change several of the wires each time I change to another number of batteries in serial. That is why I made them all banana plugs so it would be quick and easy. 



Cheers
Dave


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## Data (May 26, 2009)

Varriano said:


> The charging cradle is a thing of beauty. I think there is some modesty on display however. Reminds me of my brother in law and his comments about building furniture and restoring antiques. "All you need is a decent saw and a router". Yeah and a lot of talent.
> 
> Great job.





But everybody is a newbie when they start. :wave: I think this is the kind of project where if a person wants to try their hand at building and they are willing to post their progress here, with our help they will succeed. It does not need to be CNC machined to work. 

Thanks for the complement.


Cheers
Dave


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## skylar (May 27, 2009)

here are some shots of the one im working on. I will post more later.


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## Data (May 27, 2009)

That looks great. Did you decide on what clamps you are going to use yet?


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## skylar (May 28, 2009)

ITs going to be little different, I plan to try and use maybe two clamps. I have wait and see, through some testing. I would say im only half way through.


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## skylar (May 28, 2009)

Also as a side note, The connectors I used are the same size so I can still use banana plugs. I was trying to reduce my cost but its lot more labor.


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## skylar (Jun 30, 2009)

http://picasaweb.google.com/lh/photo/HQQ2gIxQueEXUUomxuFvig?feat=directlink

http://picasaweb.google.com/lh/photo/gdYNmcUE1nE7XLQYfyYKxw?feat=directlink

some updated photos. sorry not the best pictures in low light areas.


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## Data (Jun 30, 2009)

Very nice design. :twothumbs


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## skylar (Jun 30, 2009)

thanks not the best of looking but it works and I dont really need clamps since the brass i used is pretty heavy, and the springs do not push back up. I can't complain for my first build though. IT was fun for me. Just thought I could try something little different. with some different parts.


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## jdriller (Nov 14, 2009)

Here is my version of Data's universal battery holder. I purchased everything from ebay and home depot. The wood was some scrap I had. Dave's model inspired me to build my own because he wouldn't sell me his. It works great and was worth the time and effort. Thanks Dave!!


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## donn_ (Nov 14, 2009)

Cool! I especially like the ice auger attachments.


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## jdriller (Nov 14, 2009)

Thanks Donn! I moved them to the exotic coating thread. ooops


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## Data (Nov 14, 2009)

jdriller, 

That looks sweet! 

I know I just saw it at PF13, but I did not notice how you attached the upper contact to the clamp?

Cheers
Dave


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## jdriller (Nov 15, 2009)

I used a small brass bolt. I drilled and tapped the clamp and threaded the bolt in.
Plastic is easy to tap.


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## paetzi (Dec 18, 2009)

Hi, i have a question about how you are loading the cells.
Are you using the balancer for loading?
How is it wired from the connector of the balancer to the banana plugs?
I´ve got a single channel charging station but it has a balancer and i want to load 4 lipo 32650 cells at the same time. It´s the following station:


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## txg (Dec 25, 2009)

here is my solution for charging my 14500s in parallel: 






It's the christmas gift of my brother, he built it on his cnc mill.

works great, but you have to be careful not to overtighten the screws.


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## Data (Sep 15, 2010)

txg said:


> here is my solution for charging my 14500s in parallel:
> 
> 
> 
> ...



I did not see your post till just now. That looks perfect. Nice machining work too.

Cheers
Dave


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## skylar (Mar 22, 2012)

the power of the cnc. very nice and looks simple and clean too...


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