# improved batt charging clamp instructions



## cy (Aug 3, 2005)

Here's the latest updated charging clamp from here: EZ $3 recharging battery clamp for odd size cells  

improvements include: 

1. 14 guage monster wire (12 would be better) 8inch recommended for triton. $1
2. brass contacts, lamp parts from hardware store $1
3. mini-clamp $3
4. gold banana plugs $6 radio shak, could have used $3 version

A. secure all materials
B. cut monster cable to desired length. I did 10 inches.
C. trim cable and solder to brass fitting. 
D. remove rubber clamp pad and discard. then drill hole thru plastic clamp slighty smaller than threads. keep hole straight. 
E. thread brass fitting into plastic clamp head hole
F. attach banana clips, gold clips were solderless

your done!

Edit: picture updated to show plastic banana clips instead of gold type


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## wquiles (Aug 3, 2005)

Excellent - thanks much cy /ubbthreads/images/graemlins/goodjob.gif

I will try to build me a set (or two) this comming weekend /ubbthreads/images/graemlins/smile.gif

Will


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## cy (Aug 4, 2005)

here's a pic showing common brass lamp hardware used. note groove used to wrap cooper wire before sodering.


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## SilverFox (Aug 4, 2005)

Hello Cy,

Excellent upgrade. /ubbthreads/images/graemlins/smile.gif 

On a side note, I was just reading about some cautions when using banana plugs. It seems that if you charge 2 or 3 Li-ion cells in series and break the connection at the end of the charge by removing the banana plug from the charger, and if the two banana plugs come into contact with each other, there is enough potential to weld the plugs together. This produces a dead short on the battery and things heat up rapidly.

I ended up putting some small "O" rings around the body of my banana plugs, but think some heat shrink would be better.

At any rate, caution is advised. It is better procedure to disconnect by opening the clamp.

Tom


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## Codeman (Aug 4, 2005)

Thanks for the tip, Tom.


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## wasBlinded (Aug 4, 2005)

Very nice looking charging clamp, but I wouldn't want anyone to think that gold plugs and such heavy gauge wire is necessary. By far the high resistance point in cy's clamp charger is going to be at the point the clamp contacts the cell.


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## Doug Owen (Aug 4, 2005)

[ QUOTE ]
*SilverFox said:*

On a side note, I was just reading about some cautions when using banana plugs. It seems that if you charge 2 or 3 Li-ion cells in series and break the connection at the end of the charge by removing the banana plug from the charger, and if the two banana plugs come into contact with each other, there is enough potential to weld the plugs together. This produces a dead short on the battery and things heat up rapidly.



[/ QUOTE ]

Excellent point.

A good practice to get into with things like this is to offest the ends a bit. Make one say two inches longer than the other. It makes 'accidents' very difficult. This even only comes up because the connections are against 'the rules', as the source male. Energy sources should always be female (like the lamp and outlet it's plugged into). Consider extension cords......

There's a sexist line in there somewhere....

Doug Owen


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## stringj (Aug 4, 2005)

[ QUOTE ]
It seems that if you charge 2 or 3 Li-ion cells in series and break the connection at the end of the charge by removing the banana plug from the charger, and if the two banana plugs come into contact with each other, there is enough potential to weld the plugs together. This produces a dead short on the battery and things heat up rapidly.

[/ QUOTE ] 

That is why that is a bad practice to begin with. I have always used sermos connectors to connect to cells when charging since no electrical contacts are exposed should I need to unplug things in a hurry. Thank you for bringing this subject up.

Jerry


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## cy (Aug 4, 2005)

silver, excellent point about dead-short danger with those fancy gold banana plugs. 

off they go.. in favor of plastic bodies ones. I may try off setting one plug also.


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## wptski (Aug 4, 2005)

cy:

Is the diameter of the knurled head of the screw small enough to make contact on any cell? I've seen on RCR123 cells that the amount of wrapper overlap varies by manufacturer and making contact at the negative end a problem!


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## Lynx_Arc (Aug 4, 2005)

I like using the dual banana plugin setup. I don't know the seperation of the plugs on the triton but a lot of power supplies and meters using banana plugs space them apart so you can use them. This eliminates plugs ever touching each other and reduces stress of either wire on the plugin by essentially transferring the shock/jerk to both sockets. They also make stackable dual plugins which would allow you to plug in other items like perhaps an external voltmater etc or if desired another clamp to charge batteries in parallel (not necessarily recommended).


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## cy (Aug 4, 2005)

picture is updated to reflector change to plastic handle banana plugs instead of Gold version.

also plug was off-set, had to split cable due to plug pulling out by itself.

thought about the issue post being too big for positive nipples, but no problems so far. 

wasblinded, heavy short cables to charging rig is exactly what triton and other intelligent chargers recommend.


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## wasBlinded (Aug 4, 2005)

[ QUOTE ]
*cy said:*

wasblinded, heavy short cables to charging rig is exactly what triton and other intelligent chargers recommend. 

[/ QUOTE ]

And when charging at the extremely high currents into high amp-hour battery packs that RC guys use, large gauge cable is useful. But in the 1-3 amp range for flashlight cells (though there may be rare exceptions) your clamp leads are still overkill. Not a bad thing, just more than needed.


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## cy (Aug 4, 2005)

just a heads up..

for those who would rather not build their own rig. Xrunner is offering a simular batt clamp for sale here: FS: Battery clamp for recharging odd size cells


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## cy (Aug 13, 2005)

OK here's the next evolution of the charging clamp. 

simply go the next size larger clamp, purchased harbor freight tool for $4 on sale. all other instructions are the same from first page.

this will allow charging of 2D to 6 or 8AA adapters or 3x C cells.


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## Codeman (Aug 14, 2005)

Thanks for the head's up, cy. My local Harbor Freight had the 12" clamps on sale for $1.99 today.


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## lrp (Sep 23, 2005)

Cy.....I still can't find that clamp for sale!!! I would be willing to trade the Arc Ls with 123 case for someone to make me a high quality holder, just let me know if interested via email. the Arc ls is used but in very good condition.
Thanks!


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## nethiker (Sep 23, 2005)

Irp, I tracked down the thread that Cy linked to earlier. Is THIS what you were looking for?


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## Doug Owen (Sep 24, 2005)

lrp said:


> Cy.....I still can't find that clamp for sale!!! I would be willing to trade the Arc Ls with 123 case for someone to make me a high quality holder, just let me know if interested via email. the Arc ls is used but in very good condition.
> Thanks!


 
Harbor Freight has 'em, http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=46807. You might consider a few of the (new improved) $3 DMMS, Item 90899 while yer there. The clamp is $3.50, they have a smaller one that also looks promising.

Doug Owen


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## lrp (Sep 25, 2005)

Nethiker, yes that would do...are you interested? Let me know and I will send you the Arc Ls w/123 case, just send me your mailing address. Thanks!


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## lrp (Sep 29, 2005)

Thanks guys, I have emailed Mike for ordering instructions.


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## js (Oct 15, 2005)

wasBlinded said:


> [ QUOTE ]
> *cy said:*
> 
> wasblinded, heavy short cables to charging rig is exactly what triton and other intelligent chargers recommend.
> ...



wasBlinded,

Your observation is correct, but I think there is more to the story here. Schulze, for example, recommends--I suspect--such heavy gauge wire to ensure that the resistance of the wire is neglible compared to the internal resistance of the batteries. Also very low lead resistance gives a more accurate absolute measurement of the battery voltage. The Triton and isl-330 chargers both stop current periodically to monitor certain variables, mainly pack resting voltage. What else is going on I don't know.

But in any case, I agree with you that 12 or 14 gauge wire is probably over-kill, but it definitely doesn't hurt. My main point is just that it isn't recommended (by schulze) in order to reduce I^2R losses or anything, but to ensure an accurate voltage and resistance measurement of the pack itself, as opposed to the total system.

Why an absolute measurement would be required (versus a relative one) I don't know. I suspect that it is because the auto-charge function on the more sophistaced schulzes does indeed measure IR in order to calculate maximum charge current (early in the cycle). For myself, charging with the Triton, all my different charging cables are 18 or 20 gauge wire and I have had no problems so far. Perhaps it would be different if I had a 330? Who knows?


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## js (Oct 15, 2005)

On a more important note,

cy,

SWEET CHARGING CLAMP!!! I love it! Great idea. I'm going to set myself up with one of these.

I have a charging rig for the 5 cell 1/2D MagCharger and SL-20X packs made by splitting a metal D cell battery holder in two and attaching the ends to a board so that a 5 1/2D stick just fits in. Then I alligator clip onto the battery holder leads. But this wouldn't work for odd sized cells, of course.

Thanks for posting this!


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## cue003 (Nov 15, 2005)

Mental note to self. Thanks. 

Cy, are those batteries in a series or parallel configuration?

Can the triton or ICe charger for that matter charge batteries using the clamp for a series configuration? What about a parallel configuration? How would it be done, what would need to be set on the charger for say 1) 6x168a in parallel in 2 3x168a holders and say 2) 3x168a in a series configuration?

Thanks. This could very well be the answer to my problems.

Also, the triton charger needs a power supply right? Is there such a thing as a small/light power supply to go along with the charger? 

Does the ICE charger need a power supply as well? What is recommended?

Curtis


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## cue003 (Nov 15, 2005)

:bump: looking for some answers to my questions please.

Curtis


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## cy (Nov 15, 2005)

almost forgot about this old thread 

yes you can charge in series, but must use lower charge rate to fully charge. 

typically I'll charge 8x AA in a modamag carrier at .5amps. 

I've never tried charging li-ion in parallel. 

you can charge li-ion in series by selecting correct voltage. generally I prefer to charge li-ion cell in single cell mode.

yes triton requires an additional power supply. I use a large car battery, then once a week or so charge up the car batt.

main reason is my house has large voltage fluctuations, so I would need a 15amp regulated power supply :green:


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## sig-in-tx (Nov 18, 2005)

Nice idea, have to go looking for parts for one, but why not put a fuse in the lines. If shorted out pop a fuse and no fireworks.


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## cue003 (Nov 25, 2005)

Cy, what size are those screws in the clamp? They look like 1.5inch x 8/32

Is that correct? I am trying to track down the right length and size.

Curtis


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## cy (Nov 25, 2005)

don't know exact size, but go to your local hardware store. cruise the lamp repair parts and you will find all sorts of brass hardware that will work.


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## cy (Mar 24, 2006)

my charging clamp is still working fine!

how about yours?


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## wquiles (Dec 21, 2006)

cy, just found your old thread today again. Wanted to say thanks again for this - I now have two of these and they are not only useful to charge cells/packs with the Triton, but also on the bench while testing circuits/bulbs/LED's with various battery combinations (when a Bench Power Supply is not practical) :rock: 

Will


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## cy (Dec 21, 2006)

what a moldy but goody old thread  

yep they're handy as an external power source for say one CR123 or 1x 18650, etc. 

finally updated to a 20amp DC regulated power supply for triton. instead of full size car battery. 

here's a pic of brass lamp hardware used, next to ti PD for size ref.


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## Bob_G (Jan 10, 2007)

Found this old thread while searching for something else. Realized I wouldn't have bought a Triton if not for this thread  Use mine all the time, incredibly handy combo with Triton. 

Oh, that hardware is called "battery connector thingy" or some such at my local hardware store LOL.


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## TedTheLed (Jan 10, 2007)

nice clamp idea. I use little neodymium magnets to hold the alligator clips on the battery ends..
not the most secure method but works in a pinch.

(anything wrong with that?)


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## Alin10123 (Jan 11, 2007)

TedTheLed said:


> nice clamp idea. I use little neodymium magnets to hold the alligator clips on the battery ends..
> not the most secure method but works in a pinch.
> 
> (anything wrong with that?)



ahem. This would make it even easier. Creates a really secure connection too. 

https://www.candlepowerforums.com/threads/131955


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## Lips (Jan 11, 2007)

Alin10123 said:


> ahem. This would make it even easier. Creates a really secure connection too.
> 
> https://www.candlepowerforums.com/threads/131955




Magnets are great but they don't work with allot of FiveMegas battery holders...


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## TedTheLed (Jan 11, 2007)

I use balls, the clip grips 'em fairly well, they're 1/4" and less than $1. each -- there are also biggeruns and cylinders that work well..


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## cy (Jan 11, 2007)

don't use magnets because they don't work consistently on all cells. 
too easy to make a proper clamp for little $$. 

if you are only using cells that stick to magnets good. have not measured resistance if any, but don't see why magnets would not work. 

danger in magnets is folks that use them inside battery packs to make connections. dead shorts dangers!

clamps can be used to align up multiple cells. personally prefer the medium sized clamps. adjusts from tiny single cell to large multi-cell packs.


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## Alin10123 (Jan 11, 2007)

Lips said:


> Magnets are great but they don't work with allot of FiveMegas battery holders...



Um... i dont see why you would. With fivemegas holders just use his supplied charging jack and connect it straight to the charger. LOL


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## cy (Jan 11, 2007)

or easier yet... stick it in the clamp with no adapter



Alin10123 said:


> Um... i dont see why you would. With fivemegas holders just use his supplied charging jack and connect it straight to the charger. LOL


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## Alin10123 (Jan 11, 2007)

cy said:


> or easier yet... stick it in the clamp with no adapter
> 
> 
> 
> ...



That's another option. Oh well, whatever floats the individual users boat.


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## Lips (Jan 11, 2007)

Alin10123 said:


> Um... i dont see why you would. With fivemegas holders just use his supplied charging jack and connect it straight to the charger. LOL







Most FiveMega Lith Ion holders DON'T have charging jacks and are not magnetic.  

I built me a CY clamp for those :twothumbs 


Your magnets with wires are AWESOME for charging IMHO :rock: 

That's why I have 6 pairs :naughty:


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## cy (Jan 11, 2007)

...................


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## LA OZ (Feb 2, 2007)

Found your thread and will start similar project. Thanks.


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## LuxLuthor (Mar 11, 2007)

Trying to figure out the best kind of charging clamp setup to make...saw this thread. Those magnets from Alin are nice, but I got the black/red pairs from Mad MaxaBeam, and prefer having the 20G wire, and insulation protection to help prevent shorting.


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## cy (Mar 11, 2007)

have not used magnets to charge. mostly because once you have one of these super easy to make charging clamps. 

it's so easy to clamp down a cell, it's not worth getting magnet leads out. for loose cells, take a PVC tube to hold cells in alignment. or use a multi cell pack. 

my preference for AA's is some type of multi channel charger.


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## LuxLuthor (Mar 11, 2007)

cy said:


> have not used magnets to charge. mostly because once you have one of these super easy to make charging clamps.
> 
> it's so easy to clamp down a cell, it's not worth getting magnet leads out. for loose cells, take a PVC tube to hold cells in alignment. or use a multi cell pack.
> 
> my preference for AA's is some type of multi channel charger.



Yeah, I am using the new Maha C9000 new version AA/AAA charger for loose cells, but MadMax gave me 2 sets of those wires with his 64623 Torch battery packs, and they work great on that.

I think I will make your setup, but I do like Don's idea of using a PVC tube...and may get various inside diameters for various cell sizes. Do you need to cut them in 1/2 like Don did? It seems like there would be better alignment with intact tubing...that stuff is cheap enough, I may even cut several lengths for various numbers of cells & FM packs. 

I don't see a reason not to use the FM connector plug into the end on the ones that have them.

Cy, one question I had...the brass fittings you use from lamps..they have as good of conduction as you need? (I have no idea about conductive rates for various metals.)


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## cy (Mar 11, 2007)

no problem with brass making contact. fuses use brass, so can't be all bad  

thanks for link to Don's coool holder. 

almost never use five mega's charging adapter for same reason. it's too easy to clamp entire FM holder without fuss of breaking out adapter.


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## LuxLuthor (Mar 11, 2007)

I usually leave the FM battery packs with the charging plug in the light. Much easier to charge with his plug when I consider how frustrating it often is getting the threads started for the tailcap.


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## adamlau (Jan 22, 2008)

Compression fit, a novel idea!


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## LuxLuthor (Dec 17, 2008)

Cy, another thing I started using this clamp setup for is the CBA-II discharge testings. Having thick wire, adequate and compressive contact with cell terminals like the 18650 and discharging at 10-15 Amps requires lower resistance than my charging magnets which I have used adequately for <1-2 Amp charging.


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## cy (Dec 18, 2008)

super cooool... yet another use ... this charging clamp sure has turned out to be a sturdy/versatile tool. 

just charged four C nmh cells in this clamp, barely long enough. 
wrapped cells in a sheet of std 8x10 paper to hold together.


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## supergravy (Dec 21, 2008)

The clamp idea is fantastic. I ended up building mine with aluminum posts and using large rubber grommets/o-rings to help prevent using too much clamp pressure. Here is a picture:





I really like the versatility of being able to charge anything my hobby charger can handle. These aluminum posts worked so well that I came up with another related idea using springs and radio shack project boxes:





These allow me to charge two batteries at the same time (parallel). The one pictured above is for 18650 batteries, but I have made a couple of others for the smaller sizes. Here are a few more pictures:


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## LuxLuthor (Dec 21, 2008)

Great to see all these new ideas. What is that saying: "Necessity is the mother of invention."


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## SafetyBob (Dec 23, 2008)

Supergravy, excellent idea with the rubber to take up or regulate pressure applied to the battery. 

I have a hack version I use for charging now, but see what I need to do. 

Thanks for the idea, er, solution. 

Bob E.


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## Closet_Flashaholic (Mar 15, 2009)

cy said:


> here's a pic showing common brass lamp hardware used. note groove used to wrap cooper wire before sodering.



I realize that you only included battery to give a sense of size, but having a picture of a Lithium (non-rechargable) primary perhaps might give the wrong impression about the ability to recharge them using this rig - for newbies anyways...


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## Russel (Mar 15, 2009)

Here is my quick makshift version:











I took a 1/2" copper pipe coupler that I found in the garage, cut it lengthwise with a hack saw, pounded the copper flat, and cut the rectangular shapes out. Then I soldered a wire to each copper plate and hot glued the plate to the clamp. I don't recommend this for high current use due to the hot glue, but for single AA cell discharging it works fine.


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## Westy (Mar 19, 2009)

*quick thanks for this thread*

I've been searching various search terms for a while.... tomorrow hopefully I'll finally get my Triton II charger I've got 2 lights that need it and finally bought it solo accepting my USL package charger's likely bust.

Wasn't sure what I need to DIY for battery holders or not.....this thread was v. helpful thanks. I can see myself making a set of various length/ID PVC tubes with some slotting/crossdrilling in place so actual tube length isn't so critical (ie. simple bungy shock like cord for mild compression thru slot and to hold contact, should setup in seconds as well - one tube could cover one battery or 8 etc) I also came across a thread on this site (not immediately under my fingers ) with a simple 'clamp' for charging all in parallel which I liked.

I'd enjoy seeing any others folks have built.....I'm going to want to charge 12-20 AA's at a shot and not sure what's most efficient and/or effective?? (and should all being done be same type/ie. all eneloops or OK to mixup...I assume all one type, identical mah's should only be done at same time but OK to throw all in one for a 'reasonable' charge??)

Finally I'll be able to use my FM85 regularly as I'll be able to recharge it now! Thanks again.


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## Turbo Guy (Mar 19, 2009)

Cells being charged in series should all be the same. Same state of discharge,same past useage history,same capacity,etc. All of my NiMH AA and AAA cells which are charged in series are marked and kept as sets for use and charging. Chargers which have a single channel (slot) for each celll such as the La Cross C-900 or Maha C9000 are much better for mixed cells.


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## The Dane (Aug 27, 2009)

I build a spring into mine to avoid damaging the protection circuits on the cells:


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## Pummy (Dec 3, 2009)

I built one too, found the 6" clamp in a UK store called Wilkinson for £2.25, two screws and some wire to connect the gold reuseable banana plugs from Maplins (£1.79 each)







The cell you see charging is the LSD D size from Maplin I posted about a few weeks ago.

Now to go off in search of charging guides for 3 cells and 4 cells for the MC-E and SST-90 projects...


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## The Dane (Dec 3, 2009)

I'm interested in measurements on that D cell, but unfortunatly those @£$€ at Maplin wont ship NiMh's to Denmark, some hasmat bull


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## cy (Dec 4, 2009)

interesting.... this old thread is still lives :thumbsup:

still using my original clamp ... springs are a cool idea, but preference is being able to control contact by compression. 
you will get a solid contact each and every time. 

much simpler to make too... simple is good!


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## ptolemy (Jan 21, 2010)

speaker wire is 12 gauge, how thick should banana plugs be, 2mm? or thicker?

it's for thunder ac6 charger thank all


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## cy (Jan 23, 2010)

size of banana plug is decided by what you are fitting to. 
hard part is to find banana plugs large enough to fit 12gauge wire inside. 

most banana plugs are designed for test leads, which has low current requirements. vs this application which needs to support much higher current loads. 



ptolemy said:


> speaker wire is 12 gauge, how thick should banana plugs be, 2mm? or thicker?
> 
> it's for thunder ac6 charger thank all


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## The Dane (Jan 23, 2010)

ptolemy said:


> speaker wire is 12 gauge, how thick should banana plugs be, 2mm? or thicker?
> 
> it's for thunder ac6 charger thank all



Way overkill. No RC charger i know of will charge with more than 10A so something like AWG 18 is fine, and the AC6 will do 5A max. thus 18g is super.


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## Magic Matt (Jan 23, 2010)

Some Hi-Fi shops sell banana plugs that take thicker than normal wire... probably because some audiophiles think speaker cable should be thicker than industrial power cables.... so if you have trouble getting some banana plugs to fit the cable you want to use, you could try a hi-fi specialist.


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## cy (Jan 24, 2010)

this point has been debated many times .... don't know what brand hobby charger you are using.... but on chargers capable of charging multiple cells... a slight voltage drop for one cell may not make any difference, but for multiple cells... could cause charger not to work properly. thus... not only is gauge of wire important, so is length of wire. 

this clamp design is also good for other uses.... like a discharge clamp that requires larger current with solid contact, etc, etc. 

look at the history of this thread... this clamp is a proven versatile design that's easy and inexpensive to construct. 



The Dane said:


> Way overkill. No RC charger i know of will charge with more than 10A so something like AWG 18 is fine, and the AC6 will do 5A max. thus 18g is super.


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## LEDAdd1ct (Jun 4, 2011)

cy, I just want to thank you for this thread. I have a hunch a variant of your setup will be implemented on my end shortly. I received a BC8DP last week, and your design is just the ticket to get it into action!


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## cy (Jun 20, 2011)

glad to see this old thread still lives... 

tickles me that I still receive requests to make this charging clamp. 

it's so simple to make with raw materials needed readily available. most anyone can put one together in short order. my original clamp was used last night. once made these clamps are pretty durable


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## angrycookieman (Jan 7, 2012)

The simplest ideas are the best, and you guys have some nice setups. I'm going to try and find me something to make a couple charge clamps with today. Thanks for the ideas!


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## cy (Dec 21, 2012)

eight years and several chargers (now using a Cellpro Powerlab 8) later .... this charging clamp is still in action. a pretty rugged tool!






new 8 years ago


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