Skin irration with Bangle.js v2 despite covered SWD pins

[mmarquez76]

I just got my Bangle v2 and it's almost perfect. Amazing battery life, no bloatware, very readable, and actually somewhat stylish. It does everything I need it to and nothing else.

One issue, though: I'm experiencing some skin irritation, maybe from an allergic reaction to the charging contacts? I trawled the docs and found the existing page on skin irritation that can occur with the exposed SWD pins on earlier versions of the watch, but I have one of the later models that came with those pins covered.

My wrist feels itchy after wearing the watch for a while. The skin irritation is visibly limited to the lower part of my wrist, where the contacts sit when I wear the watch. When I tried switching the watch to my other wrist, I saw the same exact irritation on that wrist within a few days of wear. It also seems to get worse the tighter I wear the watch band. This is what the back of my watch looks like, for reference:

I have pictures of the skin irritation in case they're needed, but I'll spare GitHub from those rash pictures. Suffice it to say, it looks like angry red blotches on my wrist that fade after I stop wearing the watch for a while.

I've worn a few other smartwatches in the past without experiencing this; are there are any remedies for this issue or any folks who've had similar experiences? I really want this watch to work for me but this rash is a deal breaker.

[thyttan]

Just an inital quick thought: could you do a makeshift flap from electrical tape or something similar to cover the contacts? Or just tape over it between charging.

[enaon]

I just got my Bangle v2 and it's almost perfec

so this is a new watch? One of the contacts looks not new at all, it looks a bit corroded. Can you maybe take a closer clear picture?

[mmarquez76]

Sure, this is the closest picture my phone camera is capable of taking. In person, the contacts appear free of corrosion; I've been wearing this watch for a couple weeks at this point, so it might just be skin oils or water scale.

(The tape covering the SWD pins looks different now since I tried cutting a piece of vinyl electrical tape to cover the other contacts as per @thyttan's suggestion, but when I removed it to charge the watch, the smaller tape over the SWD pins came off too!)

[gfwilliams]

Thanks for the picture! It's a shame the tape came off - with it off you're very likely to experience some reaction if you did with it on!

I guess try with the bigger bit of tape as @thyttan suggested and see if that stops the allergic reaction.

Later, you could try putting a tiny drop of nail varnish or something like that on the middle 2 contacts? You'd have to be pretty careful putting it on, but that might avoid any allergic reaction from the tape?

[gfwilliams]

I'm sorry to hear you're having skin irritation issues with this. I can't recall hearing of anyone else having issues with theirs (apart from the tape issue as you noted) - and we've shipped quite a few of these now - and if you were allergic to the metal contacts I'd have expected other watches to cause you issues. The slightly dirty look of the contact seems a bit surprising though as with the middle 2 contacts covered the outer ones should stay clean and not corrode.

I don't suppose you have a multimeter handy that you could check across those two outer pins with? Normally there should be no real voltage across them (maybe 0.05v or something) but perhaps there is some issue with your Bangle and the voltage is higher?

What I'd suggest for now is maybe give the back contacts a quick wipe over with a bit of washing up liquid and water to clean them, and then put a bit of lip balm/vasoline over the area. That should still allow the charger to work fine but hopefully would provide your skin with a bit of protection.

[mmarquez76]

Well, with the target audience of the Bangle, it's a pretty good bet that I'd have a multimeter lying around :)

I checked the pins and like you said, I get less than 5 mV across the charging contacts.

I'll give it a quick clean like you said and report back.

Maybe I'm having a reaction to the adhesive on the small piece of tape covering the SWD pins? That's the only other thing that makes sense to me. What kind of tape is used for that? I do tend to be prone to allergic skin reactions.

[gfwilliams]

Perfect, thanks for checking! At 4mV I don't think there's any real worry - that's kind of what I see here too.

It's a good point about the tape! I don't know exactly what time it is - it comes in a big sheet cut into little rectangles, but there are no markings. If you're predisposed to allergis reactions it's definitely a possibility that the tape (or the glue on it) is causing problems - at least it's fallen off now!

[mmarquez76]

Following up on this thread two weeks later, I'm fairly sure the irritation was due to the adhesive on the tape covering the SWD pins.

Ever since removing the tape, I've completely stopped experiencing the itchiness and skin irritation.

[gfwilliams]

That's great - I'm glad it's sorted it for you!

I'd be interested to hear from anyone else that has experienced this - we've shipped thousands of these with the same sticky tape on them and I think this is the first time I've seen anyone have issues with it.