I have two real questions here... Im not really looking for an opinion on what people think is best, im looking for someone who really knows the correct answer...


1 which is better copper or silver battery bars.. and why...

2 is dead shorting reallly that much different then not...

i just got some new batteries today.. and i want to build them right... i have always dead shorted...but to be honest its a pain in my behind...

thanks

Hi Burbs! I took apart a bunch of old packs and all the bars peeled off the solder easily. I was using a pair of plairs. They were all "silver" bars from differant suppliers. I think the next time I'll sand or grind the bars. Dead shorting is a pain! Can't say if it is better or not since we always have dead shorted.

I am not to sure on which battery bar but dead shorting yah you will gain a little more voltage. you will lose runtime but gain more voltage i hope this is what kind of answer you where looking for the second question. Which battery company did you choose?

Brandon Snyder

I have a question i just want to know how dead shorting is a pain?

Pure silver has lower resistance than pure copper,but most battery bars are just silver plated.Is there a huge difference?I don't think it's enough to notice.IMO.

There might be different reasons to use silver.Maybe some one with electronic experience can answer that.

Deadshorting is the only way to go when running stock or 19T w/GP3300.Increased voltage all along the discharge curve and lower IRs.I build my packs tray them and deadshort from the beginning.Works with older packs too but they lose more runtime and get less voltage increrase from what I've seen with the packs I've done.

the easy way i have found to dead short is discharge down to 3.60 put is in the tray wait till lights go out take it out wrap a piece of soilder aroud the pos and neg if there is to much voltage in the pack it will just melt the soilder and not burn up our pack or get it hot.

Brandon Snyder

Hey burbs, I agree with you. I can not see any difference in bars. Now go to battery braid and the resistance goes down. I still do not know if I agree with the dead short thing. I run the same with a shorted back as a non shorted pack.

Here is a good question though. What is a better way to soilder the bars to the cells. Tin the cells first, or place the bars on and then soilder around the outside?

food for thought.

Mike,

As Bob mentioned pure silver has a lower resistance than copper. The bars are not made of pure silver of course and the plating is not pure silver either. It's always an alloy, but still lower resistance than copper. The fact that the silver is just plated makes no difference because DC current travels on the surface of the conductor. Hence why we use multistrand wire and why battery braid is the lowest resistance option. So to answer the question yes silver battery bars are better, but there isn't enough of a difference to matter on the track.

Pat

I agree with the battery braid… did a test years ago to prove it (and show a difference when discharging).
http://www.hobbytalk.com/modules.php?op=modload&name=News&file=article&sid=19

On soldering. In theory mechanical fastening is better… such as using screws in a terminal strip. Problems are two fold when soldering batteries. First is that when soldering cells we have no way to apply enough pressure to make a good mechanical bond. Second is that there is no way that you can get your battery bars to lay flush on the cell ends… no matter how well it looks like it is laying flush… it isn’t.

Your best bet is to use a high quality solder, tin the cells and the bars (and the tip of the soldering iron) and then apply your iron to the bars to melt the solder on both. If it takes more then 6 seconds then your iron does not have enough heat in it (or the tip is too small). The solder will then have filled in the microscopic pores and gaps between the bar and the cell.

burbs - Please e-mail me at batts@specpointbatteries.com. I will give you my honest opinion on all of your questions. As for dead shorting, I've digitally tested and graphed dead shorted packs until I see them in my sleep. Contact me and I'll provide you with the test results. I personally use Niftech, silver-plated bars for all of my assembly work. I don not tin the cells or bar ends. Attached is a photo showing a typical SPC assembly.

Thomas Himes

Orion made some batt.bars that had big holes on the end that soldered to the batt..with these I could really see in the middle of the bar and tell if I had a good solder joint.They were copper.I like the copper ones better they always seemed to heat up quicker .I want a good strong solder joint.There is nothing worse than a batt. bar popping loose inna race.A good quality solder (hobby shopper section ) is a must!!

SPC,

Why don't you just give your opinions on here. That is kind of the point of a discussion board. Maybe if your opinions are well thought out and grounded in solid data you'll even get a few customers out of it. There is not much point in treating this battery stuff like it is some kind of secret.

For .50 each you can get some KILLER silver bars from Team Power Push! They actually have wire melted down and made into bars, yes eral silver bars. I've used Deans, Trinity, etc and I'll never use anything else, period.
http://www.teampowerpush.com
http://www.teampowerpush.com/batterybars.html

If you want info about soldering a pack together, Tom is the best in the industry. :thumbsup: You have to see these packs in person to believe it.

SPC,

Why don't you just give your opinions on here. That is kind of the point of a discussion board. Maybe if your opinions are well thought out and grounded in solid data you'll even get a few customers out of it. There is not much point in treating this battery stuff like it is some kind of secret.

All of my testing and research is open for discussion at any time. I never meant to imply differently and I apologize if it came across as such. However in the past, in other forums/websites I've read responses to informational battery posts that bordered on cruelty. I personally received a threatening PM on another website. Honest, rational criticism is OK and welcome, cynical harassment and threats are not. Again, those issues did not happen on this forum/website. I don't visit that website any more, but that is why I asked burbs to contact me personally if he is interested in more info. As for attracting new customers, what can I say ..... this is a tough business. RC racers are a very brand-loyal group when it comes to batteries. :) I have and will continue to allow my honest cell numbers; quality pack assembly and race results speak for me.

Thomas Himes
SPC

I know all the ins and outs of dead shorting.. i pretty much have been doing it since 2000's were out....i guess i should have wrote it better...

I know dead shorting help voltage, and lowers IR... But does it help a pack stay stronger longer, then if i would not dead short...

my packs have plenty of runtime, but it seems all my dead shorted packs drop to 370-380 no matter the starting run time... id like to keep the runtime up where it should be....

woulnt a pack with higher runtime, hold punch longer then a lower runtime dead shorted pack? ie twoards the end of a run... i would like to do it whichever helps a pack stay strong the longest over the run....

also for the copper or silver question.. i bought out a guy a while back.. i got a rol of copper braid in the buyout... i saw people said braid is better... so would copper braid be better then silver bars???

thanks for all the replies so far... wish i had worded it better last night, but i wrote it after a long work day LOL// guess im just lazy he he..

Mike,

There is a pretty easy way to answer your own question. Just get some decent dead shorted stock packs and some decent mod packs, cycle them both and plot the graph. Look at the graph from the 0 to 240 second range and see which has higher voltage. I'm guessing Cory could help you with this as he has good mod packs and good dead shorted stock\19t packs that he or you could test.

Nitro-Boy,
Those Power Push battery bars are not going to be pure elemental silver. They are an alloy just like the other silver bars on the market. I don't doubt that they are a solid alloy instead of a copper bar with plating. But, as I mentioned before DC current travels over the surface of a conductor so having them be solid silver (silver alloy) accomplishes nothing but wasting your money.

Here is some food for thought.
Electrical Resistivity
Silver (pure) .00000155 ohm-cm
Copper .00000170 ohm-cm
Tin .0000115 ohm-cm
Lead .0000208 ohm-cm

The moral of this is don't waste your money on silver battery bars. The resistance of your tin/lead solder is 10 times greater than either type of battery bar. Your money is best spent on a good soldering iron along with some practice on your soldering skills.

The Power Push bars are actually made from copper wire that has been melted down and then formed into bars. They are then dipped into silver. Most bars we find on the market are stamped from sheets of copper. Generally, copper wire is more pure then copper sheet but without knowing the composition of the sheet there is no way to know for sure.

In a direct current, the electrons are spread evenly through the conductor; in an alternating current, the electrons tend to congregate along the conductor surface. Info from the Argonne National Laboratory Neutron Lab at http://www.neutron.anl.gov/hyper-physics/electric.html We can assume from this that a micrometer coating of silver on a copper bar does little to no good for conductivity. IMHO, the only real reason for silver to be applied to copper bars is to keep the copper from oxidizing.

The tests I did on the braid was years ago and I haven’t repeated the tests lately. I have heard that at 30 and 35 amp discharge rates that braid can heat up but I don’t know that for sure.

some 15 years ago, the "trend" was to buy gold bars. what is the resistance on those and why'd they go the way side?

from my experience with bars I have found that alot of the bars you guys are talking about are sliver plated and I have had problems with the plating flaking off causing my packs to fall apart. I made the switch to Orion gold bone bars and have never had a problem. wether it makes a difference? it is so tuff to actually test for this. because there are so many other factors that can affect numbers when cycling packs.

It is so tuff to actually test for this. because there are so many other factors that can affect numbers when cycling packs.


Like your actual physical connection to what ever machine your using to cycle the packs with, or how much solder is on the positive and negative bar your hooking your "high resistance" aligator clips from pack to pack with each cycle............

exactly

From my college days, I seem to recall that electricity flows on the out side of conducters. That is why plating is a plus. That said, braided wires with hundreds of small strands conduct a lot more electricty than a smaller gauge or cheaper braid with less strands. I think 2 things are considered in the capacity of a conducter, total surface area and the overall resistance of the material that the electricity flows over.
College was a long time ago, and I may not have listened to the teacher very well that day. I had know idea I might need the info for something fun like RC or I would have taken notes.
Tom

Hank is right and tom and I are wrong. The current is not conducting on the surface of the battery bars or wires. This is called the skin effect and it only occurs with very large wires and very high frequency A/C current, such as in RF antennas. The skin effect is very tiny even with household A/C current. Anyway sorry to be giving out misinformation. It's been a long time since school and I had it backwards between A/C and D/C with respect to the skin effect. I'm a mechanical engineer so I didn't pay attention in those damn EE classes anyway lol. The reason we use expensive multistranded wire in R/C racing is flexibility. Also the multi-stranded is much easier to solder.

Anyway my main point holds true. Buying silver battery bars is a waste of money, even more so now that I know the silver plating is a total and utter waste.

Someone mentioned Gold battery bars. Gold has a higher resistance than silver and it costs much more so there isn't much reason to use it. The reason gold contacts are used in the automotive industry is that gold is quite resistant to corrosion.

If we investigate further we find that a high quality copper is a better conductor then silver that is used for plating. You can generally tell how pure the copper is by how flexible it is... pure copper is fairly flexible. If we take a look at most battery bars on the market they are fairly stiff. Compare that to a battery bar from Power Push which can be bent easily.

I needed to edit this to add that the "brighteners" that are used in jewelry or silverware take away from silvers conductivity... so a "chrome" silver finish on a battery bar is counterproductive. In the end, the difference between silver and copper are so small as not to make a difference.

I wouldn't say that the silver plating is a waste. Copper can oxidize very quickly so the silver plating does help prevent that. In either case the surface to be soldered should be lightly sanded to take off any tarnish that may have formed on a silver plated bar as the tarnish is a very poor conductor.

Once the battery pack is soldered together it doesn't matter if the copper tarnishes. As long as you sand the bars and the battery before soldering, as you said, you should have no problem with pure copper.

But want about those bars that sit around in our tool boxes for years. I have bars that I bought 3 or 4 years ago. The oxidizing on copper can easily become bad enough to pit the copper which could hinder it's performance. Yes I know we are talking microscopic things here and in an ideal world it wouldn't be a problem. We also know that most people will cut corners ;) Silver plating does greatly reduce this posibility.

I like to address issues that will affect 99% of the people and we know that most likely 90+% don't solder correctly much less worry about properly sanding or prepping. I even fall into this group as sometimes at the track we are just in a hurry and don't do things the way we should.

We don't even want to get into "hard wiring" packs to ESCs before a race :) While I have no proof I have seen enough hard wire solder jobs to know that if someone takes the time to properly solder on plugs (while at home and not in a hurry) that the resistance would be lower then the majority of "hard wire" jobs done before a race. That, IMHO, is much more of a problem then the difference between copper and silver.

But hey... all the pros hard wire so that must be the way to do it!!!!

Great thread.......kudos to all you guys with all the techno stuff. I enjoy reading the entire thread and tried to digest what is said. But.........what is the answer to the questions at the beggining of this thread ? Thanx

Henry E.

My understanding is that once the copper is tarnished the tarnish acts as a protective layer preventing any further chemical reaction. My point is that a 10 year old battery bar won't be any more degradaded than a 6 month old bar, or however long it takes the bar to initially tarnish. That is why in the TarnX infomercial things you see them take the 50 yr old completely corroded penny and make it look brand new again. Now if you continually clean the bar and then let it retarnish over and over again I could see that eventually pitting the bar. Maybe I am wrong once again.

I think we've established that any battery bar on the market is going to be effectively the same with respect to conductivity.

What I'd like to discuss are people's opinions on battery bars with respect to solderability and strength. Personally I'm torn between two styles. I like the orion style "bones" or the old trinity lennon lugs because I think they are much easier to solder. On the other hand I like the bars like Deans because they seem to be much stroneger. I don't really like gluing my packs together and I hate when you take them out of the care carelessly and the bars all bend. What are people's opinions on this?

My understanding is that once the copper is tarnished the tarnish acts as a protective layer preventing any further chemical reaction. My point is that a 10 year old battery bar won't be any more degradaded than a 6 month old bar, or however long it takes the bar to initially tarnish. That is why in the TarnX infomercial things you see them take the 50 yr old completely corroded penny and make it look brand new again. Now if you continually clean the bar and then let it retarnish over and over again I could see that eventually pitting the bar. Maybe I am wrong once again.

I think we've established that any battery bar on the market is going to be effectively the same with respect to conductivity.

What I'd like to discuss are people's opinions on battery bars with respect to solderability and strength. Personally I'm torn between two styles. I like the orion style "bones" or the old trinity lennon lugs because I think they are much easier to solder. On the other hand I like the bars like Deans because they seem to be much stroneger. I don't really like gluing my packs together and I hate when you take them out of the care carelessly and the bars all bend. What are people's opinions on this?

My favorite (gimmic or not) is the KoPropo version. They claim something like "oxygen free" copper, but whatever, they are bent right for the batteries, and I too don't glue my batts so I need a strong bar. These are a tick thicker than others but still look very cool :thumbsup: .
Try em'.

Later, Bret

As you said, for the most part all bars are going to be the same. If we get technical then the softer bars will conduct better then the harder stamped bars. A line of shoe-goo is not that hard to apply and is easy to remove if needed.

Actually there is such a thing as oxygen free copper. In graduate school I used a large thermal mass made of oxygen free copper to help regulate the temperature of a quartz encased cylinder of iodine gas.

The oxygen free copper doesn't corrode, it was expensive as hell and looking at the spec sheet from the metal supplier it had the highest conductivity of anything they sold. The hunk I had was the size of a 20 oz soda bottle and cost about $500.

On another note if you need to sand the cell ends or battery bars then you need to brush up on your solder skills chances are that you are not getting a very good joint. A good solder job should be able to take any amount of pulling that a normal human with a pair of pliers can do to it without coming off the cell.

I remeber when 2000 packs first came out... we use to race with a jewlery owner.... he use to get us suposed pure silver sticks. they were about as thin as a battery bar. but square..

Actually there is such a thing as oxygen free copper.
The oxygen free copper doesn't corrode, it had the highest conductivity of anything they sold.

So do you think this may be the best bar out there too???
Later, Bret

Might be, I really dont think battery bar composition is that important. I think the "girth" of the particular bar is more important. Personally I have always like silver or gold plated bars if for nothing else for the bling bling factor LoL

Best bars ever were the MC2 silver bars ,,SRM

Promatch makes a bar
They had it designed from scratch
Here is what is on the site

"These new battery bars are manufactured from the highest quality oxygen free copper and silver plated. They have a 50% greater mass to flow more amperage than the deans bar! They have a lower profile and will fit better in the Losi and Associated cars"

I thought I seen somewhere That CE did a test on all the bars out there and the Promatch Bich'n Barz was the best out there
I will look around and see if I cna't find the info on the test

What is best about the bars too is I sell them for .29 each

I just saw a pic of the promatch bars and wow are they monsters compared to the Deans.

But don't let the size fool you
They are infact better than Deans

Mike,
There is a pretty easy way to answer your own question. Just get some decent dead shorted stock packs and some decent mod packs, cycle them both and plot the graph. Look at the graph from the 0 to 240 second range and see which has higher voltage.


I kinda got bored last year and played around alot with battery numbers, discharge curves, plotting results, etc.

Here are some packs I tested.

Before shorting versus after shorting

Pack A-4
Before---After
355------337
4.64-----4.69
10.8-----10.1

Pack A-5
355-----337
4.62----4.67
11.1----10.4

Pack H-3
342-----334
4.64----4.67
10.6----10.8

Pack H-2
344-----330
4.65----4.68
11.2----10.5

Pack H-1
350-----332
4.66----4.66
10.8----10.7

In looking at the curves I logged every 15 seconds from 0-210 sec, 0-240 sec and 0-255 sec. Everytime the shorted pack carried a high voltage throughout the entire curve. Plus the IR got better which for stock/19T racing you need.

In stock racing I am sold on Low IR. I would take a 4.67, 10.2 pack over a 4.69 10.8 pack anyday.

Now what boggles my mind is I had a pack that was 333, 4.67, 10.3 that I ran with my 3 other race packs that went 333-338 4.69 to 4.70, 9.9-10.4 and I consistently got better runs on the track with the 4.67. Explain that
That same pack (4.67) TQ'd the Norrca nats, TQ'd our Fall Classic race, and also turned my best time in 19T at my local track. I wish I knew what made that pack tick.

A guy at our local track mentioned to me that maybe that certain pack's resistence matched my motor's resistence more closely than my other packs did. Now how in the world do you get them to magically line up?? LOL

I can't really explain your odd ball pack Eric... However you must keep in mind that actual IR as reported by our Turbo35/GFXs is a number based on one point in the packs discharge curve. I forget when the reading/measurment gets taken, but it's a single point in the discharge curve. It's certianly possible that that strange/good pack you have actualy has better IR at some other point in the curve then do the other packs.

Averge voltage across the entire discharge can be miss leading for sure, I really hate to even consider it, except as a very vauge notion of how well a pack may proform... but generaly speaking if you compare the actual voltage curves then this should be pretty accurate in terms of picking and choosing which pack is best... but then I also don't rule out the possibility that there is more to it then pure voltage or even actual IR .

Personaly I wish cells came with complete voltage curves with data points like every 5 seconds during the discharge...

Back to this thing on braided connectors... If it's better... why has it virtualy disapeared from use?

Personaly I wish cells came with complete voltage curves with data points like every 5 seconds during the discharge...

That is why I log mine every 15 sec.
Cause sometimes you can have 2 identicle packs on average voltage say 4.70.
But then when you look at the average voltage from 0-210 seconds (my manual calculation) one pack might be 4.82 and the other 4.80

For stock or or 19T I would much rather run the pack that has more volts up front. You can even then start playing with charge rates which from my calculations a higher charge rate (say 8 Amps instead of 6 amps) acts like a mini deadshort taking a point or 2 from the end of the run and puts it up front, but that is a whole other discussion. LOL

Back to this thing on braided connectors... If it's better... why has it virtualy disapeared from use?

It doesnt provide structural rigidity and is harder so solder well. Personally i like it cause its so cheap, I can get a 100 ft spool for about $20.

Back to this thing on braided connectors... If it's better... why has it virtualy disapeared from use?

IMHO, because the pros use bars! Why do people hard wire? Because the pros do it. Habits, no matter how bad, are hard to break. ;)

When I started racing Stage III (remember them?) battery braid was the hot ticket. Even though there were many bars on the market almost nobody used them. Once Stage III went out of business most switched to bars because there was no other high quality braid on the market.

Lightspeed also has oxygen free copper bars,and yep they are pretty big,but i did see a diff in my packs.lower ir's.

IMHO, because the pros use bars! Why do people hard wire? Because the pros do it. Habits, no matter how bad, are hard to break. ;)

When I started racing Stage III (remember them?) battery braid was the hot ticket. Even though there were many bars on the market almost nobody used them. Once Stage III went out of business most switched to bars because there was no other high quality braid on the market.

Sure there is its sold as braided shielding by companies like allied electronics, newark, digikey etc. Thats where they got it.

Man I loved Stage III batts....

.......

What battery bar would tend to have less resistance. A smaller but thicker bar. which would have less contact area on the cell? or a thinner but wider bar.having more contact area on the cell?

OK.. as long as we're on the battery subject...

What's the latest thinking on maintenance zapping packs ? Seemed like last year there were a lot of guys zapping their packs before they charged them each time. Also lots of guys who were zapping them during the week between race weekends.

Does it really help ?? Just wondering -- I'm not hearing much about it lately.

Thx.