View Full Version : New main battery connectors allowed
Thad House
03-01-2015, 11:57
According to R25, the main battery connector is allowed to be any of the connectors from the SB series. This is a great change, and I am happy they did this.
Tristan Lall
03-01-2015, 12:17
That's an entirely reasonable change. Of course, it does make inter-team logistics potentially more difficult, but I'd recommend that if you're using a non-red/non-SB50 connection for main power, that you build and carry an adapter to the quasi-standard red SB50 connection.
There are also clones of the SB connector available from other vendors (like the AMP Power Series (http://www.te.com/catalog/minf/en/732) from TE connectivity). It might be nice for FIRST to permit those as well—consider asking on the Q&A. (If FIRST doesn't grant permission, the brand markings on the connectors will make clear who the manufacturer is, for inspection purposes.)
The Anderson SB Smart, SBS, SBE, SBO and SBX connectors may remain illegal, even if only 2 poles are installed. The Q&A should clarify this for greater certainty.
Also, as a public service announcement, note that the SB connectors (and AMP clones) are keyed: the traditional red ones won't work with anything except red and black (universal) Edit: and apparently pink also.
Al Skierkiewicz
03-01-2015, 21:59
Please be aware that SB50 connectors will continue (as of this date) to be supplied on the batteries in Spare Parts at events.
Thad House
03-01-2015, 22:38
Please be aware that SB50 connectors will continue (as of this date) to be supplied on the batteries in Spare Parts at events.
Would an adapter to conver from SB50's to any new connector be legal? It doesn't look like it according to the rules, but it would be much easier if it was. We could just make a few adapters and solve that problem.
Kevin Sevcik
03-01-2015, 22:40
That's an entirely reasonable change. Of course, it does make inter-team logistics potentially more difficult, but I'd recommend that if you're using a non-red/non-SB50 connection for main power, that you build and carry an adapter to the quasi-standard red SB50 connection.Your adapter is only going to be useful for charging batteries. R25 sounds very much like only one SB connector pair is allowed between the battery and the breaker/PDP.
In other news, the bigger connectors and larger wire that goes with them will be great for dealing with high current draws from pushing matches, etc. Next year. (Crosses fingers)
Would an adapter to conver from SB50's to any new connector be legal? It doesn't look like it according to the rules, but it would be much easier if it was. We could just make a few adapters and solve that problem.
R25 does say "connectors", but there are two connectors in the drawing.
(Of course, any adapter (if legal) is part of the ROBOT, not the battery assembly, for weight purposes.)
Tristan Lall
04-01-2015, 01:56
Your adapter is only going to be useful for charging batteries. R25 sounds very much like only one SB connector pair is allowed between the battery and the breaker/PDP.
It's unclear enough (given the use of the plural) that the Q&A can fill us in. I'd lean towards permitting it, since there are no new hazards caused or major advantages conferred.
(Thought experiment: if we assume that in the absence of a written quantity, the quantity depicted in R25's figure is mandatory, does that imply that we would have to prohibit a team from doubling up the wire running from the 120 A circuit breaker to the power distribution panel? What purpose would that serve, particularly since teams can use wire of arbitrarily large gauge? Alternatively, what if a team doubled up the SB connectors in parallel? Would that be permissible?)
Al Skierkiewicz
04-01-2015, 09:44
One connector and one set of wires. This rule is primarily for those teams wishing to use the SB120 series with the larger wire for the primary supply wiring on their robot. As have been discussed in many previous threads, there is very little improvement using this method. Adapters from SB50 to SB120 will be allowed should the need arise to use a Spare Parts battery. Adapters will not be provided and modification of Spare Parts batteries will not be allowed.
Many people have asked over the years about failures in the SB50 connectors due to over current. I have inspected more than 20 failures of these connectors, including one of our own. Not one failed due to the current. Every one I inspected failed due to mishandling, modification or failure to engage. About half were caused by team members bending the contact springs to make insertion easier. Most of the remainder were due to severe wear and/or severe corrosion on the contact surface.
Sounds like a solution looking for a problem.
I had a service truck with an SB50 mounted to the front bumper, I did bad things to that little connector, hard jump starts, an electric winch in the front tow receiver, never melted it.
... Adapters from SB50 to SB120 will be allowed should the need arise to use a Spare Parts battery. Adapters will not be provided and modification of Spare Parts batteries will not be allowed....
How can an adapter be okay when R25 clearly says:
R25 The one (1) ROBOT battery, Anderson Power Products (or APP) 2-pole SB type connectors, the one (1) main 120-amp (120A)circuit breaker (Cooper Bussman P/N: CB185-120), and the one (1) Cross The Road Electronics Power Distribution Panel (PDP,P/N: am-2856, 217-4244) shall be connected with 6 AWG wire or larger as shown in Figure 4-2.
(emphasis mine)
I don't see an adapter anywhere in figure 4-2. If they specifically show the wiring layout they want and the lead of lead inspectors says we can ignore that, how are we to know what other rules won't be enforced at events?
Kevin Sevcik
07-01-2015, 09:30
How can an adapter be okay when R25 clearly says:
(emphasis mine)
I don't see an adapter anywhere in figure 4-2. If they specifically show the wiring layout they want and the lead of lead inspectors says we can ignore that, how are we to know what other rules won't be enforced at events?Practically speaking, an adapter is ok because Al is the chief robot inspector of FRC. CD isn't a official information outlet, so a brief clarification question in the Q&A would be wise, of course. But at least we can take Al's word here that SB120 teams won't be left out to dry regarding spare parts batteries.
Al Skierkiewicz
07-01-2015, 09:31
I expect small adjustments will be made to allow teams that need to use a battery from Spare Parts. My recommendation to those teams would be to convert their robot to the SB50 connector if the need to use Spare Part batteries arises.
And while I am Chief Robot Inspector, I am not GDC and this will still require clarification in the Q&A.
Here comes my first of many warnings...
The 2015 motor rules that allow unlimited numbers of some motors does not imply that the electrical system can support multiple motor designs. A fully charged battery can supply more than 500 amps but at a vastly reduced voltage for a short time. Continuously demanding large currents from this system will lead to early battery discharge (and shortened life) and/or main breaker trips. Your mileage will vary.
Ken Streeter
10-01-2015, 16:14
This question is only tangentially related to this thread, but it didn't seem that my question really warrants a new thread, either...
Is there any difference between the (old) red SB50 connectors and the (new) pink SB50 connectors in the 2015 KoP other than the color?
Two of our new battery cables (with pink SB50 connectors) from the 2015 KoP, when connected together, require herculean force (needed to mount one in a vice) to disconnect. We don't see anything immediately wrong with either of them. We've never had this happen with two of these before.
Any suggestions on what to look for to see what is wrong? The contacts appeared to be properly oriented and in the correct position.
I didn't look at ours yet but the kids mentioned they were hard to get apart. If they are high force contacts they take about 15 pounds minimum to separate.
You can get grips for the SB series to aid in connection and disconnection if it's an issue.
Ken Streeter
11-01-2015, 21:54
I didn't look at ours yet but the kids mentioned they were hard to get apart. If they are high force contacts they take about 15 foot pounds minimum to separate.
Ours are definitely taking more than 15 foot-pounds of force! We've tried with all three combinations of pairs for the three cables that came in our KoP and they are all very difficult to get apart - way too difficult to separate in the typical confines of a robot. One pair we passed around at the meeting, and nobody could separate them by hand. It was like "The Sword in the Stone" with everybody thinking it should be easy to get them apart, but nobody could! (We did manage to separate them in a vice).
Maybe the contacts are made of uru?
Ours are definitely taking more than 15 foot-pounds of force!
How many regular pounds of force would that be?
Oops I meant pounds, not sure why I put foot in front.
But that is just the minimum spec. Every power pole I've ever installed took a great deal more when new.
Ken Streeter
11-01-2015, 22:22
How many regular pounds of force would that be?
Oops! That's what I get for hastily using the same terminology from the prior post without thinking about it...
Of course, they should be "pounds" (lbf) of force, since foot-pounds are not a unit of force, but of energy or work. Oops!
Al Skierkiewicz
12-01-2015, 07:31
Ken,
There should be no difference in the pink connectors. We have not tried mating yet, but I will put that on the list for tonight's meeting. When I inspected out KOP last week, the pink had the same contacts used in previous shipments of the KOP. The standard reel supplied, machine terminated terminals.
This question is only tangentially related to this thread, but it didn't seem that my question really warrants a new thread, either...
Is there any difference between the (old) red SB50 connectors and the (new) pink SB50 connectors in the 2015 KoP other than the color?
Two of our new battery cables (with pink SB50 connectors) from the 2015 KoP, when connected together, require herculean force (needed to mount one in a vice) to disconnect. We don't see anything immediately wrong with either of them. We've never had this happen with two of these before.
Any suggestions on what to look for to see what is wrong? The contacts appeared to be properly oriented and in the correct position.
Can confirm, had the same problem. On the Andymark website it states that the pink connector mates with the red SB50, nothing mentioned about the pink one.
Ken Streeter
12-01-2015, 08:26
Can confirm, had the same problem. On the Andymark website it states that the pink connector mates with the red SB50, nothing mentioned about the pink one.
I've been looking on the Anderson Power Products (APP) (http://www.andersonpower.com/index.html) web site for a data sheet or anything that describes the pink SB50A connector (as mentioned on the FIRSTChoice (http://firstchoicebyandymark.com/fc15-140) web site) and can't find the pink housing described anywhere. I wonder if it is a new product from APP?
The data sheets I have been able to find on the APP site describe many different SB50 connector colors (Yellow, Orange, Red, Gray, Blue, Green, Black) but have no mention of pink.
I don't have one of the pink connectors with me right now. I wonder if maybe they're not a genuine APP product?
I should probably also mention that we only seemed to have the "stuck connectors" problem when connecting two pink ones together. Connecting one red to one pink seemed to work okay.
Jon Stratis
12-01-2015, 08:37
I believe the pink ones are a special run of the connectors for breast cancer awareness, thus the pink color.
I believe the pink ones are a special run of the connectors for breast cancer awareness, thus the pink color.
That makes sense. I just assumed they were a off color batch of red.
Tristan Lall
12-01-2015, 22:01
I've been looking on the Anderson Power Products (APP) (http://www.andersonpower.com/index.html) web site for a data sheet or anything that describes the pink SB50A connector (as mentioned on the FIRSTChoice (http://firstchoicebyandymark.com/fc15-140) web site) and can't find the pink housing described anywhere. I wonder if it is a new product from APP?
The data sheets I have been able to find on the APP site describe many different SB50 connector colors (Yellow, Orange, Red, Gray, Blue, Green, Black) but have no mention of pink.
I'd never heard of a pink SB either. (That's why I had to edit the post above, per FIRST's note in the manual.)
I don't have one of the pink connectors with me right now. I wonder if maybe they're not a genuine APP product?
The clones from TE definitely say TE or AMP on the side. I don't know if clones falsely marked as Anderson products exist, but I would imagine that's a possibility. Does anyone know which supplier FIRST uses for the SB connectors, or if Anderson provides them directly?
I believe the pink ones are a special run of the connectors for breast cancer awareness, thus the pink color.
I hope not. It would be idiotic to violate their own colour code—which is supposed to be indicative of the function of the connector for error-proofing purposes—in order to promote something with no plausible connection to the product.
More likely they (intentionally or not) ran a batch of SBs using the resin intended for the pink PowerPoles.
If anyone can take an end-on photograph of the pink one alongside a red one, we can see if the keying looks identical. Look at this (http://www.powerwerx.com/anderson-powerpoles/powerpole-sets/sb50-sb-series-50-amp.html) for comparison photos of the other ones.
Christopher149
12-01-2015, 22:46
I tested 857's pink connectors (well, two anyway). Pink on the 2015 KOP battery to an existing red connector on a battery charger was an easy (but not loose) removal. Pink-on-pink was stiff to put together and take apart, but it came apart okay with some rocking side to side.
I was wondering if they donated a batch with a mistake in pigmentation, thus pink.
Al Skierkiewicz
13-01-2015, 07:53
I tried mating connectors last night from the KOP. While they were hard to mate and pull apart, they didn't seem to be any more difficult than other new connectors in the past.
dtengineering
10-02-2015, 14:26
I'm helping a rookie team here in BC this year. They got all pink connectors in their KoP. The pink connectors were a very stiff fit... they went together nicely but were very difficult to pull apart. This past weekend the battery was stuck to the robot so hard that we had to disconnect the cables from the 120A breaker and PDP and use a vise to get them apart.
I dug up an old, red, connector and it worked great with the pink connectors. But the Pink battery connectors that the team received were too tight to be swapped out during competition.
Jason
While keying of both connectors should be checked (and possibly only keying 1 pink w/ 1 red, since they seem to separate easier), the following is a solution to think about for safety purposes at least if more than 15 lbs of force to separate is necessary. At $3.00 each they are not too far out of the ballpark as far as costs and if the end that goes to the breaker is attached to the battery box by bolt attachment (as we have been doing the last few years), only 1 handle per battery attached Anderson SB50 is necessary. A small price to pay to save those students hands I would think. Just a suggestion. As, If I had to use a vice to disconnect one, I don't think I'd be reusing the connector again that was squeezed in that vice.
http://www.powerwerx.com/powerpole-accessories/sb50hdlred-sb50-red-handle-kit.html
They actually make a kit (that makes it easy), to attach it easily to that alum. or sheet metal battery box too! (though we usually just use 2 through bolts/nuts w/ countersunk heads on the battery side).
http://www.ebay.com/itm/Anderson-SB50-Cable-Clamp-990G2-6-or-8-AWG-Wire-/270413183290?
Monochron
10-02-2015, 15:30
Some more anecdotal evidence for you, our pink - pink matings are very difficult to pull apart. So far only 2 students and a couple of mentors have had the strength to separate them. Kind of limits us.
Easy solution, use only Pink or red on batteries, red only on robots. The red ones are avail everywhere and the plastic mating SB50 connectors are easily disassembled and traded out using a simple pick.
SAFETY NOTES: Just make sure that all (+) & (-) reconnection symbols for polarity are observed and double checked upon reassembly.....ALWAYS CHECK THE NEW ONES ALSO as there were some problems last year as some came assembled w/ the opposite polarity installed in the KOP!
*It is what we get for a simple easy battery switchout process and wonderfully generous donated parts. We should be able to live with it. Just do not mix pink w/ pink Anderson SB50's.
Ken Streeter
10-02-2015, 16:19
This past weekend the battery was stuck to the robot so hard that we had to disconnect the cables from the 120A breaker and PDP and use a vise to get them apart.
I'm reassured to know that we're not the only ones that have had this problem. We've found that the pink connectors are fine when mated with a red connector, but can get very stuck when connected to another pink connector.
We've put all of our pink connectors on batteries and are using only red connectors on the robot to avoid the pink-to-pink issue.
What really baffles me is the our lack of success at determining the specific "mechanism of getting stuck" when two joined pink connectors become nearly impossible to remove from each other. We haven't been able to figure out what it is about the connectors that sometimes has them get stuck to one another. The problem doesn't happen all the time, but when it does happen, they're really stuck!
dtengineering
11-02-2015, 01:18
I'm reassured to know that we're not the only ones that have had this problem. ... The problem doesn't happen all the time, but when it does happen, they're really stuck!
Yep... we'd had them together and apart several times before. It always took more effort to separate the two pink ones than it did two red ones, but it usually just fit the "stiff" category, not the "OMG" category. We all humbled ourselves grunting in futility, pulling with vise grips and prying with screwdrivers. It was suggested that separating the battery connectors was a "sword in the stone" test, and whoever managed to do it would drive the robot to victory!
Putting an old red one (recycled from an old team 1346 robot, in fact!) on the robot not only solved the problem but contributed to the recycle rush theme!
Jason
On the first couple of uses some of the members of the all gire rookie team I've been helping out did have trouble disconnecting them. Now that they have been connected and disconnected a number of times I've not had one of the students ask me or someone else to disconnect the battery for them. So I think that one of the reasons that people are experiencing easier disconnection of a red/pink combination is that the red has worn in already and any pink/pink connection is of two new connectors.
Al Skierkiewicz
11-02-2015, 07:37
I found that pulling at an angle was easier than trying to pull straight. That way one side breaks free before the other. Think of trying to "break" the connector in half in the long dimension.
It does not have anything actually to do with the Red or Pink Plastic SB Series Housings or even the housing keyings at all. It is however the "high detent" style cable ends that are being supplied w/ them (Pink SB50's), that the (opposing 4 retaining/mating springs forces the 4 cable ends together properly), spring clips lock into...With continued use, those contacts will ramp a slight amount from wear and allow less force to be required to detach them w/ each couple/decouple.
Below is the link to the Tech Data Sheet Drawing. (Notice it says "High Detent" in the Drawing Key).
http://www.powerwerx.com/techdata/5915.pdf
______________________
Now look at the SB50 Data sheet (Pay attention to the top center & lower right hand corner of that data sheet....See the drawings of the SB50 Contact choices between the high detent & low detent contacts? The High detent have a higher ramping on the contact faces that contact each other, If 2 high detent contacts are used together...Then they will require more force applied to uncouple (or pull apart). Their ramping is simply higher on the contact faces that lock together to allow the current to flow.
http://www.powerwerx.com/techdata/SB50.pdf
I Reprinted the SB50 INDIV. AVAIL. Contacts listing below from the data sheet.
50 amp Contacts*
Part Wire
Number Description AWG sq. mm
903G1 Contact set (2) 5900 #6 13.3
904G1 Contact set (2) 5915 #10/12 5.3/3.3
5900 Individual - HD #6 13.3
1307 Individual - LD #6 13.3
5952 Individual - HD #8 8.4
5953 Individual - LD #10/12 5.3/3.3
5914 Individual - HD #10 5.26
5915 Individual - HD #10/12 5.3/3.3
*Notice the HD & LD in the list?
Denotes High Detent/Low Detent contacts
Now look at the drawings lower RH corner. See the Indiv. High & Low Detent Drawings.....See the ramping differences on the contact faces that lock together? A simple design difference between the 2 on both faces-the Spring side/and the Current Flow faces.
_____________________________
NOTE: While some may think that bending the internal contacts retaining/pressure springs to possibly alleviate or lessen the pressure and make unmating them a bit easier...I personally WOULD NOT DO SO, as the mfg. spring pressure makes sure your electrical connection remains when mated, sound & consistant and less internal arcing occurs and retains the cable ends properly in the housing. Any arcing between any of the 4 contacts while the juice (current), is flowing, surely degrades the connection and causes current flow problems/arcing issues you will not see. But, you will encounter.
You would be better off just replacing the cable ends on the cables w/ low detent or just use Pink on battery ends/Red on Robots or switch the ends (contacts), to low detent on both.
Bottom line is the new PINK SB50's received (internal cable ends), seem to have the High Detent Contacts installed on them.
______________
Note: If anyone starts seeing any intermittent powering down of the robots this year whatsoever, personally then, I would switch the contact ends to high detent on all ends used in the SB50's period. The Cheap fix,....Then add a handle or 2 to make the decoupling action a bit easier.
http://www.powerwerx.com/powerpole-accessories/sb50hdlred-sb50-red-handle-kit.html
Al Skierkiewicz
11-02-2015, 18:01
NOTE: While some may think that bending the internal contacts retaining/pressure springs to possibly alleviate or lessen the pressure and make unmating them a bit easier...I personally WOULD NOT DO SO,
This is guaranteed to cause excessive heating of the connector. I have seen at least one connector every year that has failed after the team tried to modify the springs. The connector ratings (and the UL approval) is based on proper spring tension.
dtengineering
12-02-2015, 00:42
I found that pulling at an angle was easier than trying to pull straight. That way one side breaks free before the other. Think of trying to "break" the connector in half in the long dimension.
Yep... that worked for me a few times. But this weekend, those two connectors were STUCK. We pried, we wiggled, we twisted and we torqued... we wrapped the housings in high grip material... there was no way that they were coming apart.
I'm not 100% sure that we had used these two particular connectors together before... it may have been the first time that particular battery was connected to the robot. I don't really expect anyone to believe just how firmly they were stuck together because, honestly... I find it kind of hard to believe myself!
Maybe they were "ultra high detent". Or maybe we're all just wimps. :)
Jason
Al Skierkiewicz
12-02-2015, 07:21
Ah...Normally I would go with the 'wimp' definition but you beat us last night (Canucks vs. Blackhawks) so I can't say that for at least a couple of days. It might be temperature related and humidity might even factor in for new connectors.
Then add a handle or 2 to make the decoupling action a bit easier.
We made some makeshift handles by threading zip ties through the bolt holes on both of the connectors and pulling on them (with gloves on). And then promptly changed from pink connector to red on the robot.
ChuckDickerson
12-02-2015, 16:55
They make real handles apparently for this reason.
http://www.powerwerx.com/powerpole-accessories/sb50hdlred-sb50-red-handle-kit.html
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