Battery Beak

[Brandon Martus]

http://www.chiefdelphi.com/graphics/beak1.jpg


Tired of guessing which battery is the best seconds before a match starts?
Ever have a battery test at full capacity at the beginning of the season only to have it die at the start of a match?
Looking for a battery tester that is compact, portable and provides instant results?


If yes then the Battery Beak (http://www.crosstheroadelectronics.com/Beak.html) is what you are looking for. The Battery Beak is a battery health analyzer designed for use with the Lead Acid Batteries used in FRC and the NiMH batteries used in VEX Robotics.

The Beak provides information about a batteries State of Charge, Load Voltage, Internal Resistance and battery quality in less than a second.

http://www.chiefdelphi.com/graphics/beak2.jpg

The Battery Beak (http://www.crosstheroadelectronics.com/Beak.html) is new and available from Cross the Road Electronics, LLC.

www.crosstheroadelectronics.com (http://www.crosstheroadelectronics.com)

[Ether]

http://www.chiefdelphi.com/forums/showpost.php?p=1085743&postcount=12

[Jared Russell]

I am very excited that this is available, and will surely be purchasing (at least) one!

However, is there a way you could shrink the images on the portal page just a little bit? It is sort of squishing the recent posts area and making it difficult to read, even on my widescreen display.

[Aren Siekmeier]

I am very excited that this is available, and will surely be purchasing (at least) one!

However, is there a way you could shrink the images on the portal page just a little bit? It is sort of squishing the recent posts area and making it difficult to read, even on my widescreen display.

Seconded (both comments).

[billbo911]

The Battery Beak (http://www.crosstheroadelectronics.com/Beak.html) is new and available from Cross the Road Electronics, LLC.

www.crosstheroadelectronics.com (http://www.crosstheroadelectronics.com)
[/CENTER]

I searched and searched, but found no where to actually purchase it! I know Cross the Road Electronics (www.crosstheroadelectronics.com) markets through AndyMark (http://www.andymark.com), but nothing there either.
So, where and when can it be purchased?

[Andrew Lawrence]

I'm no electrical guy, so I don't know what this is competing against, but is this good? Is it worth the money, and how much would someone recommend getting this?

Thanks!

[Andrew Schreiber]

I'm no electrical guy, so I don't know what this is competing against, but is this good? Is it worth the money, and how much would someone recommend getting this?

Thanks!

I don't know the market for battery testers but I know the CTR guys, they release products when they are ready and not before.

[R.C.]

Our team has held off on buying a battery tester and we are pretty excited to buy this guy.

Mike, would you happen to have a video demo?

-RC

[Mike Copioli]

No video yet but I should have a user manual posted this week or the beginning of next week. Also Andymark will also be distributing these starting in December. In the mean time they may be purchased from the CTRE site http://www.crosstheroadelectronics.com/Beak.html , I should have an "Add to Cart" link up some time today.

[Foster]

Just ordered mine, hope to have it next week to go through our VEX battery sets before the big 3 December event.

I saw this at IRI and wanted one then, I'm very happy to see that Mike was able to turn these around through manufacturing so quick.

I'm also very happy that he took my suggestion to add a mode for the 7.2 volt VEX battery packs, this will end the "is it charged or not" at our events.

[Tom Bottiglieri]

This is a great idea! Seriously, every team should have one of these.

[thefro526]

This is a great idea! Seriously, every team should have one of these.

2012 KOP Item...? (A guy can dream)

Looks like we'll be getting one of these to test our batteries pretty soon. I'm really tired of being given a battery that 'says' it's charged and finding out that it's half dead after autonomous mode...

[de_]

How much are they ?

[Ether]

How much are they ?


Click on the "Battery Beak" link in the original post.

[de_]

oops, didn't "slide" down the complete page. The price was at the bottom.
Thanks

[BJT]

I'll buy one as soon as you shrink the picture and stop squishing the rest of the portal page. Seriously, I will :)

[DonRotolo]

http://www.chiefdelphi.com/forums/showpost.php?p=1085743&postcount=12
The web site states that it uses internal resistance.

The auto industry has been using internal resistance for battery health (but not state of charge) for many years. In general, the higher the internal resistance, the worse the condition of the battery. You must properly characterize the battery (chemistry, capacity) for this to work properly.

The screen display shows three voltage readings at different current values, I speculate that this is used in addition to internal resistance to measure battery condition. This is an even older (and some say more accurate) method for battery condition. In the auto industry, it is (or was) common to have a carbon pile load to test batteries, rule of thumb was 3x the Ah rating in amps, check the voltage at 15 seconds.

I will also speculate that state of charge is calculated by measuring open circuit voltage after a small load (like 18A for 10 seconds) is used to remove any possible surface charge.

Assuming the designer knew what she was doing, using these three methods (none of which are technically challenging) should produce repeatable results that are accurate enough for our purposes.

[Brandon Martus]

I'll buy one as soon as you shrink the picture and stop squishing the rest of the portal page. Seriously, I will :)

haha .. that was my fault. i'll fix it.

[BJT]

Sweet, I just ordered one, thanks :)

[Mark McLeod]

I've found that I need the Large Print screen version :)
Works nicely. We'll run comparisons of the Battery Beak results against the battery test plots at our next meeting.

[Mike Copioli]

The Battery Beak User Manual is now up at: http://www.crosstheroadelectronics.com/Beak.html. Please let me know if there are any typos, errors or problems with the link.

[Mark McLeod]

Here is a good battery/bad battery comparison (actual size on my screen resolution).
The third one is the good battery fresh off a charger (now rated only Fair)

The bad battery's measured badness matches our team number. :)
Take this bad battery with a grain of salt, I have another one in mind to test with that I've already independently measured the internal resistance of.

http://team358.org/public_files/BadBattery_Beak3.jpg (http://team358.org/public_files/BadBattery_Beak2.jpg) http://team358.org/public_files/GoodBattery_Beak3.jpg (http://team358.org/public_files/GoodBattery_Beak2.jpg) http://team358.org/public_files/GoodBattery_SurfaceCharge3.jpg (http://team358.org/public_files/GoodBattery_SurfaceCharge2.jpg)

[Mike Copioli]

The bad battery's measured badness matches our team number. :)]

This makes me laugh.


http://team358.org/public_files/BadBattery_Beak3.jpg (http://team358.org/public_files/BadBattery_Beak2.jpg) http://team358.org/public_files/GoodBattery_Beak3.jpg (http://team358.org/public_files/GoodBattery_Beak2.jpg) http://team358.org/public_files/GoodBattery_SurfaceCharge3.jpg (http://team358.org/public_files/GoodBattery_SurfaceCharge2.jpg)[/QUOTE]

Mark,

The first battery on the left, the one that measured as bad is discharged, Charge the battery and then perform the test again. The last battery that measured fair looks like it was just pulled off of the charger, you should let it rest for about 15 minutes to an hour to allow the surface charge to penetrate the plates. You should see about a 10% decrease in the internal resistance after this.

[Mark McLeod]

These are only batteries that I happen to have at home (Well I do have more bad batteries here, but I'm not really interested in testing obviously bad batteries except for what help it can lend on team visits).
I'll do more extensive variations when I get to the shop.


The first battery on the left, the one that measured as bad is discharged, Charge the battery and then perform the test again.
Nope, that bad battery is as fully charged as it will go :)
It really is a bad battery. It came from the recycle pile.


The last battery that measured fair looks like it was just pulled off of the charger, you should let it rest for about 15 minutes to an hour to allow the surface charge to penetrate the plates.
Understood, someone PMed a question about what it looked like if (incorrectly) tested with a surface charge, as in rapid pit battery changes with the batteries fresh off a charger.

You should see about a 10% decrease in the internal resistance after this.
The middle and right are the same battery after 10 minutes on a charger.
.026 (no surface charge) to .029 (with a surface charge) is the 10% difference you mention.
I'm waiting for the surface charge to dissipate again now to see if the resistance drops and the Beak returns to a Good rating.

[EricVanWyk]

The bad battery's measured badness matches our team number. :)

For a moment I thought the Battery Beak would actually quantify a battery's "badness" and was brought back to the days of writing in LaTeX and getting "Badness: 10000" errors.

Mike, could you add a badness rating? Please?

[Richard Wallace]

I've found that I need the Large Print screen version :)That was my comment when Mike showed it to me at IRI. Al Skierkiewicz was nearby, and he had the same comment.
What do he and I and Mark have in common, hmmm ....?

Anyway, I ordered one on Tuesday and it arrived this morning. I'm hoping it will help my new team manage batteries better this year. It won't really matter if my old eyes can read the tiny screen -- the student who is responsible for battery charging will be recording the data, not I.

[Mark McLeod]

What do he and I and Mark have in common, hmmm ....?

We're each interested in the big picture? :)

[Mike Copioli]

We're each interested in the big picture? :)

Duly noted.

[Siri]

The middle and right are the same battery after 10 minutes on a charger.
.026 (no surface charge) to .029 (with a surface charge) is the 10% difference you mention.
I'm waiting for the surface charge to dissipate again now to see if the resistance drops and the Beak returns to a Good rating.So just to make sure I understand, if I use the Beak on a battery I just finished charging in the pit, the Good ones will read "Fair" because of the higher Rint? (Do Fair batteries read "Bad"? Bad ones still read "Bad"?)

What's the minimum percent Charge that still indicates a surface charge to you (somewhere between 130% and 113%, I take it)? Is surface charge ok in actual use of the battery?

Thanks! I suspect these are stupid questions to anyone with a modicum of practical EE knowledge, but I regret I'm not really one of those people. I do need to fix this.

[Ether]

So just to make sure I understand, if I use the Beak on a battery I just finished charging in the pit

Don't do that. The results will be unpredictable.


Is surface charge ok in actual use of the battery?

Yes, assuming the battery is healthy and the surface charge is not fooling you into thinking the battery is good.



Thanks! I suspect these are stupid questions to anyone with a modicum of practical EE knowledge,

They are not stupid questions. They are important questions.

[Siri]

Don't do that. The results will be unpredictable.Ok, we'll continue to just run these tests pre-competition, thanks. How long is long enough to wait after charging, or are we waiting for a specific charge percentage?

[Ether]

How long is long enough to wait after charging

Some websites say 48 hours (for automotive lead/acid batteries). The user manual for the FRC tester says 15 minutes if charge rate is limited to 6 amps (FRC battery is smaller).

[DonRotolo]

OK, so here is a challenge for the students out there. No fair if you've left High School...

Given the claims of the Battery Beak, design experiments to verify that it really works. Claims include:

Determines battery State of Charge
Determines battery internal resistance
Labels the battery good, fair or bad
Provides results in a second or so
Surface charge dissipates in 15 minutes at a slow (<6A) charge rate
>all assuming a standard FRC battery at room temperature

Pick one or more of these claims and figure out how to verify it.

Any takers?

[Mike Copioli]

So just to make sure I understand, if I use the Beak on a battery I just finished charging in the pit, the Good ones will read "Fair" because of the higher Rint? (Do Fair batteries read "Bad"? Bad ones still read "Bad"?)

Not necessarily, the batteries Mark tested had a higher than normal internal resistance it just so happened that the last battery was right at the threshold between 'Good' and 'Fair'. I would reserve that battery for practice only. A good rule of thumb for surface charge in SLA like the ones used in FRC is 10%. What this means is; if you take a battery directly off of a charger and then test it you get a 10% increase in the internal resistance and SOC from the surface charge that has not had time to penetrate the lead plates. For a healthy, new FRC battery this should not cause a 'Good' battery to read 'Fair'


What's the minimum percent Charge that still indicates a surface charge to you (somewhere between 130% and 113%, I take it)? Is surface charge ok in actual use of the battery?"

Surface charge is a result of the chemical reaction inside the battery being slower than the rate of charge provided by the charger. There is always some surface charge when a battery is first removed from the charger due to this reaction, it is perfectly normal. Again it accounts for apx 10% of the total charge in FRC. In other words the surface charge is deterministic and not unpredictable. So if you wanted to test your battery right after removing it from the charger just deduct 10% from the result. Or let it rest for about 5-15 minutes.


Thanks! I suspect these are stupid questions to anyone with a modicum of practical EE knowledge, but I regret I'm not really one of those people. I do need to fix this.


These are valid questions that we asked ourselves during the time spent developing this device. As it turns out surface charge is not a large of a variable as we expected.

[Mike Copioli]

And just to clarify one point:

Surface charge will NOT cause the Battery Beak to read a 'Bad' battery as 'Good'. I would stake my reputation, my company and my NON ANONYMOUS user name on it.

[Ether]

Do users need to be concerned at all about the battery temperature affecting the readings (e.g. cold trailer in the winter, hot trailer in the summer)?

[Mike Copioli]

Is this true even if the battery has been charged at a rate higher than 6 amps, and is hot?




Yes, surface charge is weaker than deep charge. This behavior causes a small increase in internal resistance as measured by the Beak. This increase, if the battery's internal resistance is within 10% of the threshold between 'Good' and 'Fair' or 'Fair' and 'Bad', could only cause a battery's status to appear worse than it would be if the battery had been properly rested. This is one of the reasons the 'Fair' Status exists, otherwise it would just be 'Good' or 'Bad'. If a battery is that close to the threshold you should probably reserve it for practice only.

[sanddrag]

I know some other teams have used the CBA III from West Mountain radio as a battery analyzer, and I'd speculate there are others available. I like that the Battery Beak is all self contained and does not need a computer interface. Is there anything else that compares? I just want to look at all available options before I go buy one.

[Mike Copioli]

I know some other teams have used the CBA III from West Mountain radio as a battery analyzer, and I'd speculate there are others available. I like that the Battery Beak is all self contained and does not need a computer interface.



The CBA series of testers measure battery capacity by applying a load until a specified cutoff voltage is reached and then calculating capacity in Amp Hours, the Beak measures battery internal resistance by applying two different loads and then calculating internal resistance. Both tests are of value and important to understanding the health of your battery. What the beak provides is a quick way of assessing the health of your battery between capacity tests at competitions without completely discharging your battery.


Is there anything else that compares? I just want to look at all available options before I go buy one.

Internal resistance testers have been around for years, but most of them are very expensive. As far as I know the Beak is the only internal resistance tester that was specifically designed around the types of batteries used in FRC, VEX and FTC.

[alphadog0309]

Would this be a relevant purchase for FTC teams? We've been having some battery issues recently and we are looking at all possible ways to fix these issues.

[Mike Copioli]

Would this be a relevant purchase for FTC teams? We've been having some battery issues recently and we are looking at all possible ways to fix these issues.

Yes, in fact the Beak was designed to work with the 12 volt 3000 mAh NIMH batteries used in FTC.

[Mike Copioli]

A short video of the Beak is now available. Special thanks to Lauren and Adam from team 3539, the Byting Bulldogs.

http://www.crosstheroadelectronics.com/Beak.html

[nuggetsyl]

I have not read any of these posts so if i repeat something sorry. I saw this in action at IRI. There is no question in my mind that its a must to be a top level player. Even if the voltage is high it can still tell when a battery is about to fail. Don't be cheap buy the device. Each first round costs a team about $500 to play. Think of this as insurance that you be playing the round and not sitting with a dead robot on the field.

[Marvin Kraska]

Just got mine - looks like it will be a great time saver in the pit, should help us sort out all our batteries. I really like the quick test and display. It absoutely confirmed a marginal battery that we had marked as "suspect" from competition.

Thanks!!!

[Andrew Lawrence]

Just got mine - looks like it will be a great time saver in the pit, should help us sort out all our batteries. I really like the quick test and display. It absoutely confirmed a marginal battery that we had marked as "suspect" from competition.

Thanks!!!

On a scale of 1 to 10, 1 being "not worth your time", and 10 being "ZOMG MUST GET NOW WELL WORTH THE INVESTMENT", how would you rate it for a team?

[Marvin Kraska]

If your team has a "battery wisperer" (somone who knows and understands batteries) that tracks and manages your batteries, they would probably
give it at least a 9. It takes two measurements at different currents
(small and large, the small (1A) is like the current of the cRIO alone, the larger current is like one window motor (18A) in less than a second, and displays both voltages and currents for you to review. You can tell how the battery will support a load even though it looks fine with small or no load.

If your team doesn't have a "battery wisperer", your electrical team would probably still give it at least a 9. The quickness of the test, and the simplified classification of Charge, Bad, Fair, or Good will help your team screen out potentially bad batteries. The multi-chemistry feature lets you test the NiMH batteries from those smaller 'bots, although you have to go into a setup menu to switch back and forth between battery types.

Does you team absolutely need it to participate? Not if you have a good "battery wisperer" on the team.

Will it help your team compete with a mix of older and newer batteries? Yes, I would buy one as soon as I could purchase it. It quickly provides real information about the battery's health. The simple classification and state of charge display may flag a marginal battery as bad, but the measurements are displayed so you can make your own judgement.

Very cool product, a tad expensive, but very quick and convienient, based on fundamental voltage and current measurements.

So far, very happy with it.

[Foster]

Ummm "battery whisperer", an interesting title.

I have both the Battery Beak and the CBAII load tester. I've done tests on the VEX battery packs using both devices. The Beak is good at pulling out a quick snapshot of the existing battery status. The CBAII is good at looking at the long term load. I have found a battery that has a cell that will fail under load. The Beak does not show it (and I would not expect it to), where the CBAII picks it up about 30 seconds into the test.

I'll work with the FRC team to get them to charge all their battery packs and run a dual Beak/CBAII run to rate the battery sets into practice / competition battery sets.

It would be nice to have the CBAIII, since it can put a heavier load on the battery packs. The prior year swerve base with the 4 active CIM's can draw more than the CBAII can simulate.

[Ether]

I have found a battery that has a cell that will fail under load. The Beak does not show it (and I would not expect it to), where the CBAII picks it up about 30 seconds into the test.

Would you be willing to post a plot of the CBAII data for the above battery?

Does it look something like the link in this (http://www.chiefdelphi.com/forums/showpost.php?p=916447&postcount=1) post?

[RedLeader342]

Team 342 is already using this. It makes things much easier and since you can let it hang around your neck it also makes it faster. we love it

[Foster]

Would you be willing to post a plot of the CBAII data for the above battery?

Does it look something like the link in this (http://www.chiefdelphi.com/forums/showpost.php?p=916447&postcount=1) post?



Pretty much like that, swap 8V for the peak, 30 seconds for the first drop point and you've got it. There is only one dead cell, so only I have only the first drop. Mine then shows a flat line of power (good) after that. The battery at the link shows two bad cells (the second voltage drop)

I'm going to say that the battery would also show as good by the Beak. This battery would cause the classic "The robot works for the autonomous then stops running, must be a (software, mechanical, field control) problem."

[Marvin Kraska]

Very interesting. So one (or two) cells have only 3 amp-hour capacity,
and those weak links cause the battery voltage to drop when they are
discharged. The Beak does not significantly discharge the battery,
but if those cells have a high internal resistance, they would show up.
But if they have low internal resistance (like the rest of the cells), just
reduced capacity, they will not show up in a Beak test. It would be
interesting to see what the Beak reports for Rint on the known bad
and a known good battery.

If you have access to a 50A or 100A car battery load tester, I would
be interested to see if the subject battery tests "bad" compared to
a known good one. (Normally test is something like apply a 50A
or 100A load for ~10secs, read the voltage before removing the load. The load tester will get hot, don't leave it connected more than 15sec)
Terminal voltage under such a heavy load should be >10.5v, and >11v
is pretty good. If the voltage is not slowly dropping (unsteady, jumping, or
quick drops), then individual cells are not contributing properly. I bet
the bad battery charges real quick - you only get to put in 3-4 amp-hours
before the terminal voltage rises, and the battery appears full. Hence you
only get 3-4 amp-hours out, more load is less run time.

I also have a CBA-II, and capacity test batteries when we get new ones, both to see if the tested amp-hours matches spec, and the shape of the
discharge curve. It takes quite a while (>3hours at 6A load), and you really
want to recharge the battery imediately after the test - don't leave it in a discharged state, that limits our ability to test during working time.
The Beak is quick, but dosen't do a discharge test. Both have a place
in our shop.

[Gdeaver]

Foster and I have talked about the 2 units. I suspect that to really know a battery a fixed load like 50 amps for at least a minute will tell the true story. That is a hard test to make an instrument for. We have many batteries in varying condition and age. Since Foster has both units, we will go thru all our batteries and that should tell allot about the value of both devices. Good project for in a couple weeks when students are sick of drilling holes and machining.

[Marvin Kraska]

Foster and I have talked about the 2 units. I suspect that to really know a battery a fixed load like 50 amps for at least a minute will tell the true story. That is a hard test to make an instrument for. We have many batteries in varying condition and age. Since Foster has both units, we will go thru all our batteries and that should tell allot about the value of both devices. Good project for in a couple weeks when students are sick of drilling holes and machining.

Agree - best test is a real 2 minute match at 100A ::ouch:: !

When you run a CBA load test, please use a reasonable cut-off voltage to end the test - I usually test at 6A (which is 18AH/3, or C/3 in battery speak) to a end of test voltage of 10.3v (look at the discharge curves in the battery spec sheet, there should be at least C/5 (~4A), C/2 (9A), and C (18A) curves, and they stop at different voltages, just interpolate to get voltage for C/3). There is no value to running the battery down to 6 or 7 volts - you can't compare to manufacturers specs, and the deep discharge may
actualy damage the battery.

We do the same - look for a time when students are looking for a change of pace.

[Elgin Clock]

I know this JUST came out, but are there plans for an in-series version to measure a battery under a true load while connected to the robot?

Just a thought I had (all while COMPLETLY ignoring the fact that the HUD on the classmate can show the same thing (I believe?) & that the old IFI controllers did the same thing as well somehow). lol

[Al Skierkiewicz]

Marvin et al.
West Mountain does make an higher current version of the CBA II. When we run our tests, I set the CBA for the highest current it can test at, about 7.5 amps as I remember. We run the test to match manufacturer specs which I believe is 8 volts terminal voltage to duplicate the manufacturer's amp hour test. In the case of two damaged cells, a 10 volt cutoff might not show the second cell in Hugh' test.
The Battery Beak cannot test the depleted cells shown in Hugh's linked graph because the battery is good until the drop in cell voltage. It would likely show a different internal resistance on the Beak. How different only time and additional testing will show. Mike may have already done this testing. I believe the change we are seeing is due to damaged plates within the cell. Either a partial beak within a plate or an entire plate breaking off the plate connector. Any battery I have found with these deficiencies has always had some evidence of a drop when looking closely at the outside of the battery case.

[Marvin Kraska]

You are correct - the discharge cutoff voltage depends on the discharge rate. Discharge at 7.5A would be 7.5A/18AH = 0.417C. The best datasheet I ran across tonight was from YUASA http://www.farnell.com/datasheets/575631.pdf, the discharge curve for the NP18-12 shows a cutoff voltage of 10v for 0.4C, 9.5v for 0.6C, so I would cut off testing at about 9.9 volts. You would measure only 12.4AH for a good, "nominal" 18AH battery (see the General Specs on the right side of page 1, the discharge would be to 1.65 volts per cell) [18AH is at the C/20 rate] The difference in measured capacity is due to power lost in the internal resistance of the battery, and reduced conversion efficiency at higher discharge rates (google "Peukert exponent").

I agree - the Beak does a very short time load test, if that's not enough to discharge the weakest cell, it won't show up as a voltage drop. But the battery might still show a higher internal resistance, since the other cells are probably stressed by overcharge/discharge as the weak cell drops out and charges prematurely.

Dropping batteries should be avoided for a lot of reasons, we don't usually think about internal damage, but plates and internal connecting bars can break inside the case. I'll be sure to check the battery case on any "problem" batteries from now on!

Thanks!

[Al Skierkiewicz]

Marvin,
As you may note on the discharge graphs, the curves imply that they can go down to 8 volts so that is the one I use to insure as close to printed data as possible. If the total battery runs a curve as shown for 0.4 C discharge or very close we will consider it good. By choosing 8 as a cutoff I can prevent total discharge yet still make a reasonable curve. If it doesn't match, we will let it rest, then recharge and then test again. Two failures are enough to add it to the practice pile. A spectacular will get it a free trip to the recycle pile by the entrance.