Addressing the Achilles Heel - Meet the Improved BKB Xenith V2 🚨

So it is common knowledge that the previous-gen PCB had one major achilles heel: unreliable and unpredictable switches. Personally, we were not aware of how big of an issue this was until the first batch of Xenith’s. With a relatively small first batch, we had blown the switches on ~$5k with of product. In our QC testing we managed to catch most of them, but a handful of customers still had issues.

This is simply not acceptable, and is the very reason why the second batch was delayed so long. Some of you may not be aware, but BKB kits are used by quite a few colleges/universities in the USA. This has allowed us to build relationships with great professors, and in particular one of the largest engineering universities (by enrollment) in the USA. At this particular university, single motor tayto kits are the basis for a multidisciplinary introduction to engineering class. We were able to work with a few of the TA’s and students pursing advanced degrees to troubleshoot the switch and find a reliable solution. They did a lot of work in a short time, so all the credit goes to the (soon to be) engineers! With that said…

Meet the improved BKB Xenith V2!

Q: Whats different?
A: We have swapped/upgraded a few key componets to the switch circuit. This results in a far more reliable switch with no physical change to the outside of the Xenith. This batch does have MR60 connectors instead of MT60.

Q: What testing have you done?
A: The upgraded Xenith has been through 3,000 power cycles at 58V with flawless operation. It is hard to provide a number of cycles the previous gen was able to complete because it is so inconsistent. Some would fail at 1 cycle, 5 cycles, or 100 cycles. The students were not able to determine why this issue occurs on some switches, while others function normally. While it did not effect every PCB, it was definitely a large enough problem that needed to be addressed.

Q: Whats the price?
A: Same as before! $229

Q: Are they in stock?
A: Yes! We have very limited stock available now. More will become available in a ~2 weeks as we need to do some manual work to each ESC (for reasons you can assume).

Q: I have an old Xenith, now what?
A: Well, if the switch has not failed by now you should be just fine! We will not be offering an upgrade where you send back a V1 Xenith due to the amount of precison manual work required to change the components on the PCB.

Q:Where can I buy one?
A: If you are in the USA, directly on our website! For our UK friends, @ApexBoards will be receiving V2 stock soon, as well as @janpom for EU customers.

Q: What firmware will be installed?
A: FW23.46 will come pre-installed. There have been a few issues with 5.X firmware, so we cannot continue to take the risk of sending non-stable firmware. You can upgrade it at your own risk.

Q: Are there any challenges?
A: Yes, as with any change to a product, there is a minisule chance that the changes will cause some kind of issue. All of them were related to the switch circuit, so the functionality is still the same. I am confident in the amount of testing that was done, but risk is still there. In the event that something does happen, we will fully stand behind what we sell.

Q: How easy is it to setup?
A: With FW23.46 guided setup only takes ~5 minutes! It is far less intimidating than the full VESC Tool. You can download the Xenith Easy UI here: How to set up the BKB Xenith - buildkitboards

Xenith Easy UI Sources are available here: XENITHUI · Build-Kit-Boards/FOCBOX_UI@e7d7488 · GitHub


Man this is sick! Great Job Jared and everyone working on it!


now all we need is the apk version of it…for u know…reasons


Sources are there if someone can get it to work! I messed with it forever and could not get it to compile


Any of those engineering students also able to write firmware? :stuck_out_tongue:


This is actually so cool bro.


so sick! Congrats Jared!

Its been a pleasure to work with you so far. @ApexBoards stock is on the way and will be with us very soon! If they are anything like the last batch they will go very soon!


This is really awesome


Well this is fucking cool! Super neat to have an army of engineering students troubleshooting these controllers!


No one cares about the switch, This is obviously the best improvement.


Great work, Jared! Just to confirm for those of us who constantly second guess what we think we know, if the built in switch on my V1 blows, or I want to be proactive, I can just remove/bypass the switch with an XT90s and be good, correct?

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Awesome work @BuildKitBoards, many congrats and keep up delivering the highest quality products!

Already waiting for my unit thanks to @janpom :call_me_hand:

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I think that the issue is caused by chip HC4066 (analog switch). You would need to by new chip for 1-2 $ and solder it to the board.

Just guessing.


Does this mean that warranty is voided if switching FW?

Excellent work on the switch by the way, awesome to see the consumers giving back :+1:


No, the firmware shouldn’t damage the ESC, just you


giphy (25)


@BuildKitBoards what do you guys do with the warranty zeniths? I’m sure you’d have customers if you sold them on here as-is


Does this mean that the students have to buy a Tayto for their class? Even if they get it at cost, BKB is getting some really low cost R&D right now and then an army of future return customers and ambassadors.


Nope! The schools buy them for students. Generally the smaller schools/classes get one per student, and the larger schools get one per 3-4 students.

If any of you are currently enrolled in an engineering program, let your professors know about BKB!


I would be one of them. In fact, I’d probably be more than one of them!