{"id":5569,"date":"2024-02-01T20:02:12","date_gmt":"2024-02-01T19:02:12","guid":{"rendered":"https:\/\/eskerahn.dk\/?p=5569"},"modified":"2025-03-09T10:51:22","modified_gmt":"2025-03-09T09:51:22","slug":"cheap-ecg-smartwatch-and-breast-strap","status":"publish","type":"post","link":"https:\/\/eskerahn.dk\/?p=5569","title":{"rendered":"E600, E500, E400 Cheap ECG smartwatches w. breast strap"},"content":{"rendered":"

I bought this cheap E600 smart watch out of curiosity of what a breast strap mount can do.<\/p>\n

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And it is certainly better than I expected for the price, though not without its flaws!<\/p>\n

UPDATE:<\/strong> The first unit is broken<\/strong> after just six weeks<\/strong>, refusing to charge!!
\nUPDATE II<\/strong> The E400 is broken with same failure, bought a E420, and adjusted a bit on that.<\/p>\n

<\/p>\n

I bought the smartwatch including a breast strap, stickers, and extra band, and you can get that less tax including shipping “as an early bird” offer for $21 from here<\/a><\/del> That special price has gone, other sell it for $31<\/a><\/em>. (I stupidly paid $49 from another seller – silly me, at the least I was not that<\/em> much of a sucker that I paid $284<\/a><\/span>).<\/p>\n

The watch alone is available for $23<\/a> (including shipping, less taxes).<\/p>\n

 <\/p>\n

E600, E610, E500, E400, …<\/h2>\n

This watch exists with the same internals in a number of variations, varying in shapes, displays and buttons.<\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
<\/th>\nE600<\/th>\nE610<\/span><\/th>\nE500<\/th>\nE400<\/th>\n<\/tr>\n
Width<\/td>\n26.0mm<\/td>\n~26mm<\/span><\/td>\n36.1mm<\/td>\n44.6mm<\/td>\n<\/tr>\n
Total case height<\/td>\n50.5<\/strong>mm<\/td>\n~50mm<\/span><\/td>\n52.0mm<\/td>\n52.5mm<\/td>\n<\/tr>\n
Display dimensions, diagonal<\/td>\n1.47″<\/td>\n1.47″<\/span><\/td>\n1.63″-1.79″ (*)<\/td>\n\u00f81.32″<\/td>\n<\/tr>\n
Display dimensions (mm)<\/td>\n17.7mm \u00d7 32.9mm<\/td>\n17.7mm \u00d7 32.9mm<\/span><\/td>\n29.4mm \u00d7 34.8mm (*)<\/td>\n\u00f833.5mm<\/td>\n<\/tr>\n
Display pixels (mm)<\/td>\n172 \u00d7 320<\/td>\n172 \u00d7 320<\/span><\/td>\n240 \u00d7 284<\/td>\n\u00f8360<\/td>\n<\/tr>\n
Display DPI<\/td>\n247<\/td>\n247<\/span><\/td>\n207<\/td>\n272<\/td>\n<\/tr>\n
Weight (less band)<\/td>\n18.17g<\/td>\n~18g<\/span><\/td>\n37.56g<\/td>\n40.86g<\/td>\n<\/tr>\n
Thickness less protrusion<\/td>\n~11.6mm<\/td>\n~11.6mm<\/span><\/td>\n(11.8mm)<\/span><\/td>\n(12.7mm)<\/span><\/td>\n<\/tr>\n
Thickness incl protrusion<\/td>\n13.95<\/strong>mm<\/td>\n~14.2mm<\/span><\/td>\n13.85mm<\/td>\n14.4mm<\/td>\n<\/tr>\n
Thickness with breast strap<\/td>\n21.0mm<\/td>\n~21.0mm<\/span><\/td>\n20.6mm<\/td>\n21.8mm<\/td>\n<\/tr>\n
Band width, (std. pin)<\/td>\n20mm<\/td>\n20mm<\/span><\/td>\n22mm<\/td>\n22mm<\/td>\n<\/tr>\n
Battery capacity<\/td>\n160mAh<\/td>\n160mAh<\/span><\/td>\n280mAh<\/td>\n280mAh<\/td>\n<\/tr>\n
Push buttons\/touch disable<\/td>\nnone!\/no<\/strong><\/span><\/td>\nnone!\/no<\/strong><\/span><\/td>\nOne\/yes<\/strong><\/span><\/td>\nTwo\/yes<\/strong><\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

The E610 dimensions, are estimates as almost identical to the E600, less the left side electrode removed, and the right shortened.
\n(I have got the E500 and E400 also later, and revised info above, the thickness less protrusion is meaningless really, as it covers almost the whole back)<\/p>\n

(*) The display-size is a little hard to give correctly for the E500 due to the nicely rounded corners. The diagonal for the outer rectangle (1.79″) as well as Width and Height ignores the corners. The actual display diagonal (1.63″) should not be compared with a completely rectangular display…<\/p>\n

The lack of real buttons on the E600 (E610) is bad when used on a breast strap, as you can not disable touch…. (That is why I ordered the others too…)<\/p>\n

It seem the that the E600 has been (or is being) superseded by a E610<\/a> with identical specs, slightly different sides (the left side electrode removed, and the right shortened), and less smooth transition between case and band. The right side of the E610 is not<\/em> a real button.<\/p>\n

Here to rendering images with exaggerated displays (not real photos)
\n\"\"<\/a><\/p>\n

But I guess they in ads can claim the E610 as shorter, excluding the arms, but that is just marketing BS, it is really the same size, and they have NOT upgraded the display to AMOLED..<\/p>\n

The three E?00 models are not quite as identical as I thought at first, there is at the least one LED more on the E500 than the E600.<\/p>\n

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(And yes it is on purpose I rotated the E600, so the sensor arrangement is similar)<\/p>\n

In the image the three LEDS top down are R,G,R &\u00a0 R,G,R respectively R,G, so one less red on the E600.<\/p>\n

Notice the screws also – not that I think I will be able to service it, but out of curiosity I tried to open one, but it needs more than loosening the screws. Maybe some heat to loosen any sealing? Unfortunately the E600, seems like a unibody, closed with the display.<\/p>\n

They can all be woken from Off connection to the charger OR with a long press on the button (upper for E400, button-area for the E600).<\/p>\n

Upgraded variants<\/h3>\n

Similar to the E610, there are variants of E400\/E500 called E420\/E530.
\nThe info on the various models are a little ‘flaky’, to say the least, so not quite<\/em> sure what is correct, and what perhaps have been updated internally too (apart from firmware).<\/p>\n

From what I gathered from various sites, the majority (!) seems to agree on these
\nThe E400 -\u25ba E420 includes a 1.32″-\u25ba1.39″ bump (same resolution), The E420 is about 1mm wider and longer, and 1.0g heavier. They are both 14.4mm thick, but on the E400 the glass is protected by being recessed about 1mm, the E420 is practically flush.
\nYou may also view a looooong compare video here,<\/a> I recommend double play speed… (spoiler alert: no really noticed differences, except firmware)<\/p>\n

And E500 -\u25ba E530 is even more unclear as most sites claim the E500 as 1.92″ but that is the CASE<\/span><\/strong> not the display!!! And many sites say 1.91″ for the E530. The only visible change I’ve spotted is a changed button design….<\/p>\n

I am unsure if the ET580\/E481 are further upgrades or competitors. They come with amoled, and different chips, and does not<\/strong> seem to be supporting breast band. So I think<\/em> competitor is the most likely. The ad material also seems substantially different.<\/p>\n

 <\/p>\n

E600 Exterior<\/h2>\n

It does not feel as cheap as it actually is (!), but it is not signalling premium exclusivity either… The back is just plastic.<\/p>\n

Here a few real-life images. With the first the same as the ad-image above….<\/p>\n

\"\"<\/a> \"\"<\/a><\/p>\n

Note that I have the brightness set at just 4 of 12 on the watch, but had the background light in the room cranked up high, so the display is far from as bad as the images here could indicate. The reading angle should be fairly straight on to have a good image though, some +\/- 45\u00b0 perhaps. It has been grey and rainy for days, so have not tested the outdoor legibility. There are no ambient light sensor to regulate (AFAIK). Here with full light and straight on (ambient light cranked up at same high level)<\/p>\n

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The band attachment is quite well thought trough! It can go in any direction from straight down around a 4\u00bdcm wide very small wrist, to flat out for as large as you can get a band! And this is done without it looking ‘odd’ at any angle.<\/p>\n

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So in that aspect is can suit a large range of different arm-sizes. (Strictly it can even go narrower than straight down, but that is rather academic…)<\/p>\n

The band uses a standard 20mm pin attachment, so there are zillions of alternatives to match personal taste out there.<\/p>\n

The sensor block (17.6mm x 24.1mm x 2.6mm), is so big that it really is the shape of the back rather than a “protrusion” seen on most, and talking about how much less thick the device is outside makes little sense. It is so big that the edges of the house is hoovering over the arm.<\/p>\n

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So it is not that it is particularly wearable, and it feels really clumsy compared to my T8<\/a> on the other arm (yes wearing both while testing), and the shirt certainly easily got caught<\/p>\n

\"\"<\/a> \"\"<\/a><\/p>\n

compare that to the T8:<\/p>\n

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 <\/p>\n

The E600 got no physical buttons. No microphone nor speaker. No NFC nor GPS.<\/p>\n

They are focussing on the health aspect. So not a complaint, just a fact.<\/p>\n

You can read notifications and control music though.<\/p>\n

The display is simple TFT, so no AOD as it is not AMOLED, e-ink or lcd.<\/p>\n

 <\/p>\n

Specs<\/h2>\n

Here on the E600 from one source<\/a>, I have not been able to find out the manufacturer… But it MIGHT be Shenzhen Shengye Technology Co.<\/a>
\n<\/em><\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Hardware Parameters<\/td>\n<\/tr>\n
CPU<\/td>\nGR5515<\/td>\n<\/tr>\n
RAM<\/td>\n128 MbFLASH<\/td>\n<\/tr>\n
Display<\/td>\n1.47-inch 172 x 320 HD touch screen (E600 only)<\/span><\/strong><\/td>\n<\/tr>\n
Touch Panel<\/td>\nFull Touch Screen<\/td>\n<\/tr>\n
ECG chip<\/td>\nTYHX3220<\/td>\n<\/tr>\n
PPG chip<\/td>\nSFH2201<\/td>\n<\/tr>\n
Blood oxygen<\/td>\nGH3220 RF analog front-end+ SFH2201<\/td>\n<\/tr>\n
G-sensor<\/td>\nRohm KXTJ3-1057<\/td>\n<\/tr>\n
BT Version<\/td>\n5.1<\/td>\n<\/tr>\n
Battery<\/td>\n160mAh Lithium Polymer Battery<\/td>\n<\/tr>\n
Stand-by Time: 30Days<\/td>\n<\/tr>\n
Typical Use Time: 7Days<\/td>\n<\/tr>\n
Certificates: TO BE DONE<\/td>\n<\/tr>\n
GPS<\/td>\nNo<\/td>\n<\/tr>\n
Vibration Motor<\/td>\nSupport<\/td>\n<\/tr>\n
Speaker<\/td>\nNo<\/td>\n<\/tr>\n
Microphone<\/td>\nNo<\/td>\n<\/tr>\n
Structive Components Parameters<\/td>\n<\/tr>\n
Middle Frame<\/td>\nZinc Alloy<\/td>\n<\/tr>\n
Middle Frame Color<\/td>\nDefault Black Color<\/td>\n<\/tr>\n
Back Case<\/td>\nPC+ABS<\/td>\n<\/tr>\n
Straps<\/td>\nSilicone,Leather<\/td>\n<\/tr>\n
Button<\/td>\n1 Buttons<\/td>\n<\/tr>\n
Charging Structure<\/td>\nMagnetic Pins Charing<\/td>\n<\/tr>\n
Waterproof Level<\/td>\nIP68<\/td>\n<\/tr>\n
Function Parameters<\/td>\n<\/tr>\n
Watch Languages<\/td>\nAvailable in Russian, Hungarian, Turkish, German, Italian, Czech, Slovak, Japanese, French, Polish, Persian, simplified Chinese, traditional Chinese, English, Portuguese, Spanish, Vietnamese, Arabic, Korean<\/td>\n<\/tr>\n
APP Languages<\/td>\nChinese (simplified and Traditional), Korean, Japanese, English, German, French, Italian, Spanish, Portuguese (Portuguese), Russian, Hungarian, Turkish, Indonesian, Polish, Czech, Greek, Swedish<\/td>\n<\/tr>\n
Sport Modes<\/td>\nMultiple motion mode.<\/td>\n<\/tr>\n
Health Functions<\/td>\nIntelligent ECG blood glucose health watch, ECG, chest patch real-time ECG analysis, ECG monitoring, non-invasive blood glucose, heart rate monitoring, blood pressure monitoring, blood oxygen monitoring, exercise record. Sleep monitoring,<\/td>\n<\/tr>\n
Other Functions<\/td>\n1.39-inch 360*360 HD touch screen (E400 only!)<\/strong><\/span>
\nmulti-exercise mode, custom dial, online multi-dial,call and message reminder, ultra low power consumption and long endurance.Metal alloy case, silent alarm clock, remote photo, music control, sitting reminder, drink water reminder, weather display, countdown, shake to take photos, mobile phone search.<\/td>\n<\/tr>\n
BT Push Information<\/td>\nTwitter, Facebook, Gmail, WhatApp, Messenger, QQ, WeChat, News, Texts etc.<\/td>\n<\/tr>\n
APP Name<\/td>\nH Band<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

 <\/p>\n

Battery & Stamina<\/h2>\n

E600<\/h3>\n

The “low power consumption design<\/em>” shall be taken with a pinch of salt, to say the least.<\/p>\n

The initial days with all monitoring ON and dozens of ECG-tests, I think the stamina was about 2-3 days. I see NO indications with a percentage, just an icon, in either the app (two places) or on the watch. While charging is it also just an icon, so a little hard to really tell how fast it discharges. It charges with just 0.05mA , and at the end to as little as 0.0375, 0.025mA, and finally 0.0125mA!!<\/p>\n

I charged it fully. And with all sensors on, it did an AutoOff after 5 days and 7 hours, BUT it began stopping recordings after precisely 4 days, some ran a few hours extra(??).<\/p>\n

So the conclusion is FOUR DAYS <\/strong>sharp. And that is with all sensors active, BUT no manual ECG or exercises<\/strong>.
\nIt charged the first about 75% in 1\u00bd hour at the ‘full’ 0.05A. And shortly after that it starts reducing, to 0.0375A.<\/p>\n

After two hours<\/strong> (less two minutes) it says “Charging complete<\/strong>” briefly, but still pulls 0.0375A then 0.025A and finally 0.0125A<\/p>\n

All in all a FULL charge to it pulling less than 0.01A. took three hours<\/strong> (perhaps less a few minutes).<\/span><\/p>\n

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All in all quite underwhelming in the power handling!!<\/p>\n

E500<\/h3>\n

The E500 like the E600 charges with at the most just 0.05A, despite the capacity being 175%. So expect loooong full charge time, something in the order of 4-5 hours…<\/p>\n

On the other hand the E500 offers the percentage indicator missing on the E600!<\/p>\n

E400<\/h3>\n

The E400 seems to be much like the E500.<\/p>\n

At “72%” to “100%” the E400 charged with a mere 28mA… \ud83d\ude25 BUT it continues to do so about an hour(!) after “100%” is reached, before reducing the current to about 15mA, and that it uses for almost three hours more! So charging 4h AFTER “100%” was displayed… \ud83d\ude44
\nAND it charged from claimed\u00a0 “72%” to “100%” in 22 minutes?!?!). Doing\u00a0 a little calculus here 28mAh 5V =140mW. Under theoretical<\/em> ideal conditions with no loss<\/em> allowing all 140mW to charge (there will always be waste, so this only give us an upper limit)<\/span>, that would be 38mA 3.7V, so IF the “72%” and “100%” were real, that meant 28% of a 280mAh battery=78mAh entered the battery, so with 38mA, that should have taken two hours…. So<\/strong> do not take the numbers at face value!!!! Just use them as indicators for lower&higher state of charge, and you can not really se when it actually IS fully charged, unless you use an amp-meter of some sort, so really should stay in the charger for many many hours, maybe eight hours!!<\/p>\n

 <\/p>\n

Breast strap mount, E600 only<\/h2>\n

Note that this is for the E600 ONLY, not the E610, or any of the other, due to almost rotational symmetry of the E600.<\/p>\n

I struggled quite a bit with the breast strap and the E600 as the images in the manual and the listing are self contradicting, and thus wrong<\/strong>!<\/p>\n

You can unfortunately physically attach the E600 in either way on the plastic plate, but the orientation matters, and the orientation of the band in the images was wrong too!<\/p>\n

Note that the watch should be attached to the plate with the home ‘button’ towards the small text “ECG” (the side with one electrode). And when worn, this end should be away<\/em> from the heart. That is the end with two electrodes towards the heart. It shall be worn quite high, above nipples height (they have hinted that slightly in image 04 below).
\nHere I tried to correct the image from the ad, by rotating\/mirroring various elements!!! (marked what I did with green arrows.)
\n\"\"<\/a><\/p>\n

(The same flawed images are in the small manual that came with the band)<\/p>\n

It is fairly easy to swap usage between wrist band and breast strap usage.<\/p>\n

 <\/p>\n

Breast strap mount, all models<\/h2>\n

T<\/strong>he breast-strap is intended for ECG (PTT) measurements only<\/em>!! [See section later….]
\nThat is they do not even do heart rate, though it works fine for ECG and PTT… Weird.<\/p>\n

Despite what the images indicate, you do NOT need to remove the band ends for the E600 (you do<\/strong> for the E400 and E500 though). Here I clicked the E600 onto the plastic plate with a band<\/p>\n

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Obviously if you are not wearing some shirt or T-shirt over you will have the two band ends dangling, here the plate clicked on the band, and mounted.<\/p>\n

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If you want to use the strap for ECG-testing only, it requires you to be at rest anyway (measuring while moving not supported, and reports as sinus arrhythmia), so in that case the dangling ends are not really an issue, and much to prefer over fiddling with detaching and re-attaching the two ends of the band every time IMHO.<\/p>\n

If you want to use the device only for ECG and PTT with the breast strap and not on the wrist, you obviously should detach the band.<\/p>\n

Mounted it sticks out about 2cm from the back of the band, and though that may sound a bit much, you actually do not notice it when wearing a normal casual shirt. (or a shirt and a tie). If you are wearing something tight like a T-shirt I guess it will be visible and look a bit odd though, if worn when not exercising.<\/p>\n

Especially with this usage the E600 is lacking an option to select to temporarily disable<\/em> the touch and display, so there is a risk of inadvertent interaction (and waste of battery).<\/p>\n

If you place it a bit lower on the breast you will get a more clear R pulse but a less clear T and P pulse (see below ECG section for letters)
\nIf you (like me) are fat, the lower mount will be right above the belly, and this helps hiding the watch under garments, even a T-shirt…<\/p>\n

Here the back with the three conductive lanes (click to enlarge..)<\/p>\n

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 <\/p>\n

Health functions offered<\/h2>\n

It offers the following monitoring, that can be selected on\/off individually, but monitoring is at a fixed 5min interval for (almost) everything.<\/p>\n

Monitoring 24\/7:<\/p>\n