Computerized Battery Analyzer

Technical Electrical
21

The display on the BD250 is not all that useful. It is limited in # of digits and alternates between displaying several values (and does not tell you which one it’s showing), so it’s confusing to read. I rely almost completely on the DisCharger software as the interface to the device. The display is occasionally useful to glance at during a test, but I wouldn’t really care if it wasn’t there.

I looked at the BD350 manual and it says on p. 2 “As of the time of releasing, the BD350 discharger only works with T1000.” So that is a significant drawback that probably rules it out for most teams (since the T1000 is several hundred dollars more). However it looks like the BD380 doesn’t have that same limitation and is in the same price range. Again, I have no direct experience with either of these models.

22

Popped for a BD250 (not just for FRC usage but other battery characterization).

Ran a cycle on an FRC battery via the front panel - painful but it seemed to do what I expected.

Downloaded the software but it seems that under Win11, the device briefly shows up as something under device manager (so fast you can’t see what it instantiates as but it does cause a refresh). Never seems to connect from the software.

Tried a number of different sequences of battery under test and USB connections to no avail.

I’m assuming my unit is just on the fritz or am I missing some magic incarnation? Instructions on this thing are somewhat “thin”…

Amazon already said they’d replace it but that’s basically what they say about anything…

23

Most of the time I’ve run the BD250 from my personal laptop which is Win10. I don’t remember there being any drama with drivers or anything when originally setting it up. I will be at our shop tomorrow, will plug it into one of the team’s Win11 laptops and see what it does.

24

Curious to see what it instantiates as under Device Manager if it’s not too much of a hassle.

Thanks in advance.

25

I tried with a Win11 laptop, no issues, it connected right up. You do generally need a battery connected to it or it will go into low voltage alarm immediately, at least with the firmware we have.

It enumerated as an HID device, which is a little curious, but :man_shrugging:

Have you tried more than one USB cable? I’ve had more than a few flaky micro-USB cables along the way…

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26

Under my Win11 box (which is pretty new), it fails to read the device descriptor. I only mention “new” because that means it’s probably still relatively clean and started as a Win11 box and not an upgraded older system.

Thought about the cable as there are a lot of garbage and charge-only cables flying around but was able to use the same cable and plug it into an Ubuntu 22 system.

Output from dmesg:

[Sun Sep 15 18:12:14 2024] usb 1-1.1.1: new full-speed USB device number 17 using xhci_hcd
[Sun Sep 15 18:12:14 2024] usb 1-1.1.1: New USB device found, idVendor=0000, idProduct=0001, bcdDevice= 2.00
[Sun Sep 15 18:12:14 2024] usb 1-1.1.1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[Sun Sep 15 18:12:14 2024] usb 1-1.1.1: Product: GD32 USB IAP
[Sun Sep 15 18:12:14 2024] usb 1-1.1.1: Manufacturer: GD32 Microelectronics
[Sun Sep 15 18:12:14 2024] usb 1-1.1.1: SerialNumber: 䌰䈸M3210
[Sun Sep 15 18:12:14 2024] input: GD32 Microelectronics GD32 USB IAP as /devices/pci0000:00/0000:00:14.0/usb1/1-1/1-1.1/1-1.1.1/1-1.1.1:1.0/0003:0000:0001.000E/input/input45
[Sun Sep 15 18:12:14 2024] hid-generic 0003:0000:0001.000E: input,hidraw9: USB HID v1.01 Device [GD32 Microelectronics GD32 USB IAP] on usb-0000:00:14.0-1.1.1/input0

It showed up - funky idVendor and idProduct values - typical of products that don’t set that stuff because they don’t register for a vendor ID and leave things at the chipset default. That could give Windows some fits but Ubuntu seemed to roll with it and actually talk to the device.

lsusb -t seemed to confirm it as an HID device as well:

/:  Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/10p, 10000M
    |__ Port 1: Dev 2, If 0, Class=Hub, Driver=hub/4p, 5000M
        |__ Port 1: Dev 3, If 0, Class=Hub, Driver=hub/4p, 5000M
        |__ Port 4: Dev 4, If 0, Class=Hub, Driver=hub/4p, 5000M
/:  Bus 01.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/16p, 480M
    |__ Port 1: Dev 2, If 0, Class=Hub, Driver=hub/4p, 480M
        |__ Port 3: Dev 8, If 3, Class=Human Interface Device, Driver=usbhid, 12M
        |__ Port 3: Dev 8, If 1, Class=Audio, Driver=snd-usb-audio, 12M
        |__ Port 3: Dev 8, If 2, Class=Audio, Driver=snd-usb-audio, 12M
        |__ Port 3: Dev 8, If 0, Class=Audio, Driver=snd-usb-audio, 12M
        |__ Port 1: Dev 4, If 0, Class=Hub, Driver=hub/4p, 480M
            |__ Port 4: Dev 12, If 3, Class=Human Interface Device, Driver=, 12M
            |__ Port 4: Dev 12, If 1, Class=Human Interface Device, Driver=usbhid, 12M
            |__ Port 4: Dev 12, If 2, Class=Human Interface Device, Driver=usbhid, 12M
            |__ Port 4: Dev 12, If 0, Class=Human Interface Device, Driver=usbhid, 12M
            |__ Port 2: Dev 7, If 2, Class=Audio, Driver=snd-usb-audio, 12M
            |__ Port 2: Dev 7, If 0, Class=Audio, Driver=snd-usb-audio, 12M
            |__ Port 2: Dev 7, If 3, Class=Human Interface Device, Driver=usbhid, 12M
            |__ Port 2: Dev 7, If 1, Class=Audio, Driver=snd-usb-audio, 12M
            |__ Port 3: Dev 10, If 2, Class=Audio, Driver=snd-usb-audio, 480M
            |__ Port 3: Dev 10, If 0, Class=Video, Driver=, 480M
            |__ Port 3: Dev 10, If 3, Class=Audio, Driver=snd-usb-audio, 480M
            |__ Port 3: Dev 10, If 1, Class=Video, Driver=, 480M
            |__ Port 1: Dev 17, If 0, Class=Human Interface Device, Driver=usbhid, 12M

It’s there under Ubuntu and it’s a HID device as you saw as well.

Makes me think the cable is OK and this is going to be a Windows driver hunt.

The GD32 is a family of microcontrollers, some with USB - need to dig as little into their stuff. Their dev toolkits might contain some drivers for their chipsets.

Thanks for checking into this from your side.

I’ll post any updates in the event that it helps anyone else…

27

FWIW, the Win11 laptop I used had been freshly re-imaged from a USB stick not that long ago, so it hadn’t been upgraded either. I did download the DisCharger application so I could try it, but didn’t do anything special in terms of loading drivers. I also wonder if there’s any chance that SkyRC rev’d the hardware along the way, such that our unit and yours differ.

28

Guitar Hero controllers and DDR pads are old hat, when will we see robots controlled by analyzing batteries?

29

I might be leaning in that direction as well - the hokey USB product and vendor id values seem to suggest someone messed up on that version of the firmware. It’s a shame that if you can’t talk to it under Windows, you can’t update the firmware if there is a fix.

I’ve got an older Win10 box I’ll fire up and try.

So far I’ve seen this with 2 brand new units in the last week so it might be something in the latest versions.

Reaching out to SkyRC via their chatbot, not having high hopes here.

30

Doesn’t instantiate on my Win10 system either. Bummer but it’s going back (both of them).

No response from SkyRC - too bad but this things dead to me - bummer.

“Caveat emptor” I guess…

31

90% of the value of a battery tester is in an Amp-hours number. 10% is in sweet discharge graphs… The BD250 will do the Amp-hours question just fine without a computer.

32

I agree but I’ll just fall back to my resistor bank and pocket the $100.

Mostly it’s that I’m just sort of po’d by the fact that it’s a software-wise brick for their own software and there is no response from the company. That probably ticks me off more than anything so no money from me.

As you mentioned, getting a basic Amp-hour reading is really what you want but I don’t want to do it with their device anymore.

3 Likes
33

I’ve been reading through the various posts concerning battery testing. It’s been very informative! I am a newbie in this field so I find it very helpful (thanks to Weldingrod1, bbonner, Mr_V and all for these discussions). I’ve procured a SkyRC BD380 to use for testing, and am ready to start. I need to work on the unit and understand how to output test data, etc, but I have some basic questions with which the answers can hopefully shed some light on moving forward.

  1. Is priming/formatting a battery recommended? I understand that repeated charge/discharge cycles impact the battery life, but it may be more critical to have the battery at full performance capabilities when needed rather than focus on longevity. Interested what the consensus is on number of charge/discharge cycles and discharge rate to achieve this?
  2. We are using Duracell 12V 18 Ah AGM batteries. I am in contact with Duracell to see if it is possible to obtain information on the maximum life cycles of this battery based on the depth of discharge, and the resulting state of discharge, but have yet had any success (still working on it). Is this information typically available with battery suppliers?
  3. As far as testing batteries:
    a. The BD380 has a 40A discharge capability, which may better represent in-use conditions for the FRC applications and has the benefit of shorter test times. Is this too aggressive?
    b. As Weldingrod1 mentioned “The key factor in battery life is depth of discharge, which we are controlling with the terminating Voltage.”, yet rated capacity depends upon the discharge rate. Therefore, if I cannot find published data on capacity vs discharge rate, how do you determine the baseline for a “golden” battery from which you compare the performance of old batteries? Do you do this empirically by testing a new battery and then compare the test performance of old batteries to the “golden” battery?
    c. Any recommendations on initial terminating voltage at the 40A discharge rate (assuming 40A is an acceptable test condition)?
    d. Any recommendations on pass/fail battery capacity at 40A discharge rate (assuming 40A is an acceptable test condition)?
    I know I will have more questions as I become more familiar with battery testing, but I truly appreciate the collaborative nature of these discussions. Thanks in advance.
34

I suggest 10.5 Volts.

Any current up to 50 Amps is good.

Yes, low current gives you a higher capacity, but we don’t use the batteries that way; we use high current in competition! So, a low Amp test doesnt give you more useful data and (much more critically!) takes faaaar too long. You can get 6 or more 50 Amp tests done in one meeting, but you may not get even one low amp test done at all!

I wish I had formatting data or information… maybe some day!

All the battery folks should have load/DOD/temperature vs cycle life data, but they are totally interchangeable. No real difference in chemistry or construction.

I would expect a new-ish battery to give you something like 17-18 Ahrs in a test.

Here’s our match batteries after a season. Julian and Turkey are NOT ok for a match! All the rest of these will do a solid match.
Eduardo: 10.64 Amp hours
Fingle: 10.52 Amp hours
Konor: 10.29 Amp hours
Battman: 9.04 Amp hours
Suleyman: 8.93 Amp hours
Julian: 7.11 Amp hours
Derrick 8.7 Ah
Turkey/seko… 5.4 Ah
Brenda 10.1 Ah
Noah 9.2 Ah

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35

Thank you. This is good information.

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36

I purchased the BD380, but it doesn’t appear I can access data, output charts probably as I did not purchase a skyrc charger (nothing that I can find in the manual). You have the 250. How do you control the 250, access data, export charts, etc? I may need to return this unit and get that one

For example,

  • Using the mobile app, I will save the output chart from a test, but cannot find the saved file anywhere. Searched phone multiple ways. The mobile app software is extremely limited. Any test data procured is lost.

  • My laptop and PC are not recognized when I plug in the USB and launch the SkyRC software (Charger Master, Discharger)

Using google or chatgpt to find a solution has been unsuccessful.

Getting help from SkyRC is useless, nothing from chats or emails. When I call China, the line hangs up on me.

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37

You’ll find varying strategies. I prefer to run our new batteries through a gentle 7.5A discharge the first time, then a higher current (15 to 22A) cycle, then ideally a couple of cycles of drive practice before actual competition use. (Encourage your drivers NOT to push your brand new competition batteries past brownout levels, though!) But before we had the BD250 we’d just break them in with drive practice use since we didn’t really have an alternative!

I’m going to guess that they’re unlikely to share much more than is on the spec sheet. The FRC use case is pretty abusive and I doubt the manufacturers will commit to much under those circumstances.

We typically get one season of competition use out of a battery, then one or two years of practice field use. They usually stay around for secondary uses for a couple more years before we recycle them.

No, 40A is a lot more gentle than the robot is going to be! Just remember that the amp-hour result you get will be lower the faster you discharge it. (The “18Ah” rating assumes you’re only pulling 0.9A!) So you probably want to pick a “standard” rate that you use for testing so you can compare results.

Our standard rating (the one we log, and write on the side of the battery each time we test it) is at the maximum 250W discharge rate that our tester can perform. That way it’s apples-to-apples.

We use 10.8V, which is 1.8V/cell. I absolutely would not go below 10.5V or you risk damaging the battery. Again, pick a number and use it consistently.

I don’t have experience with a 40A discharge rate, so you may need to do some experimenting. Whatever standard rate you settle on, you’ll probably pretty quickly figure out how the batteries bin out. I recommend tracking the information in a spreadsheet and retesting annually (before the season) so you know where each battery stands. Also, chemistry can be a funny thing - there’s some variability with each run, and I’ve even had batteries test out higher a year later on occasion.

Note than even weaker batteries still have a place for work in the shop, running inverters to power laptops, and things like that. But with the tester, you’ll know which ones those are!

Honestly, I just plug my laptop into its USB port and run the DisCharger application. It’s always just worked. Though as noted above, @zog had issues getting it to work properly. I wonder if one of the forums for other user bases might have any info? (RC cars, drones, whatever.)

38

Love the bullet by bullet responses. Thank you!

1 Like
39

I’m having a somewhat similar experience. Eventually the Discharger software recognized it and was able to start a test. The device very quickly disappears from my laptop and the test stops.

My laptop is Windows 11 and I tried multipe usb cables.

40

You’ve had better luck than I had - I couldn’t get within reach of the Discharger app.

I suspect a firmware bug in a batch of devices - it’s a shame because if you can’t talk to the device using the Discharger app, you can’t update the firmware. I shudder to think what you end up with if the device disconnects in the middle of a firmware update…