I wrote this in a reply to a previous mi band thread..

So I've got this. I've had a mi band pretty much since release and I really like it. Here's what I've found with the heart monitor;

While Running;
-If you start a running activity, the heart rate monitoring will be continuous until you stop the activity. It will give you an average heart rate at the end of the run. I run my preferred run tracker (runkeeper) at the same time. At the end of the run I edit the runkeeper activity to add my average heart rate. There is no provision to extract all the data, or see a graph, you only get the average heart rate. You need to have your phone with you while you run.
-You can set an alert to warn you if you reach a particular heart rate. I set it too low when I tried it and it was buzzing every minute or so and was very annoying. I read Chris Ryan's SAS fitness a couple of years ago and it suggested that you could exercise vigorously until hitting a target heart rate, and then 'rest' for a bit, before bringing yourself back up to your target heart rate. I need to do some research as there's a lot of conflicting info about heart rate zones, but this could be a useful feature.

While Sleeping
-There is an option to sporadically check your heart rate while sleeping. This promises to provide more detailed sleep tracking, at the expense of a bit of battery. There is no visual difference to the sleep graph.

User Activated
-You can use the app to ask the band to check your pulse whenever you like. I've had a few erroneous results but on the whole it's accurate.

If you are not going to run with your phone (and you are not bothered about more accurate sleep tracking) I would suggest either not upgrading or buying a generation 1 mi band. You can check your pulse using your smart phone camera and an app (I use instant heart rate for android, but there's a plethora of options) Not upgrading will afford you better battery life.

got one of these....awful.... truly awful. thinks you're walking when you aren't. wear it to bed and it reckons you've walked hundreds of steps but also slept for 4 hours. absolute garbage

rubbish, I walked 250 metres in my sleep apparently

I must have one with a bad battery. Not worth sending it back to China and it's too late to open a dispute on aliexpress. Anyone know of a UK seller who I can buy from that I can return it to if I get another faulty one?

Sorry. Yes that's the original. The point about only getting a day or so being a fault rather than a characteristic stands though. Someone above says 3 weeks is to be expected for the heart rate one.

40 days with the original or the heart rate though? The heart rate has a lower battery so I was impressed by 40 days, that's with no notifications though, I think you're stretching it with easily 40 days on a heart one with multiple notifications as Xiaomi only quote a few weeks/

​I got mine from Amazon. 3rd one worked but the tracking was not accurate. I'm not the only person to be annoyed that the silicone gets looser and looser until one day you'll be running for a bus or something and it'll fall out.

I easily get 40 days out of mine and that's with a daily alarm and notifications for SMS, Whatsapp and GMail enabled in the Android app. SANGER_A2 must have a faulty one or a fake.

Had the old version. Took 3 attempts to get one that actually worked. It was utter trash with it's tracking for both steps and sleep.

The rubber band stretches after a few months and the tracker fell off it once as I was walking along and decided to not replace it.

Wouldn't trust something this cheap to be any better.

This deal is only £10.86 now!

Mine lasts 40 days between charges, it was you who's doing it wrong or not charging it properly.

Been using one of these for a few months. Absolutely love it.

Sleep tracking is fantastic. Battery life about 3 weeks between charges.

Heart rate is a bit hit and miss.

Cheap products but. very bad customer service. don't expect a refund if you get a faulty item from gearbest.

​Grab a drink? I'm sitting here with my flask! Never come across that site before and very in depth reviews as you suggested. Thanks

Currently have a fit bit flex but that isn't able to track cycling afaik. Can anyone recommend a tracker that will do cycling and also HR?

I had this band since Dec'15. Band works fine but the corresponding iOS app got an upgrade in March and since then have been either crashing or unable to synchronise complete data from band. Tried reinstalling app which meant deleting historical data but no luck. So unable to review data collected by band...

is gearbest a china company?

won't let me add to basket, horrible site. got my partner the non heart rate version of this at Xmas, she charged it for the 1st time last week. nearly 3 months on 1 charge, constantly connected to her Bluetooth. pedometer is pretty accurate, sleep tracking is not so good. sometimes she goes for a run in her sleep.
hear nothing but awful reviews about the heart rate function.

I also have one but find the heart rate monitor extremely inaccurate . Good for a pedometer but that's about it. Great battery life though, lasts months

Got three of them for £9.49 from a seller on ali express

Would not waste your money..I've had mine for about 3 months, I never go running but apparently I do about 3 hrs a day, I sleep like a baby but according to this I sleep about 45 minutes a night and my resting heart rate is about 157....Even sat at my desk at work typing it thinks I'm off jogging..On the plus side very light, hardly notice I'm wearing it and the battery lasts about a month, which is just perfect for getting my inaccurate activity stats without worrying about charging.

I can highly recommend this wrist watch.I have one, it's perfect.

I wrote this in a reply to a previous mi band thread..

So I've got this. I've had a mi band pretty much since release and I really like it. Here's what I've found with the heart monitor;

While Running;
-If you start a running activity, the heart rate monitoring will be continuous until you stop the activity. It will give you an average heart rate at the end of the run. I run my preferred run tracker (runkeeper) at the same time. At the end of the run I edit the runkeeper activity to add my average heart rate. There is no provision to extract all the data, or see a graph, you only get the average heart rate. You need to have your phone with you while you run.
-You can set an alert to warn you if you reach a particular heart rate. I set it too low when I tried it and it was buzzing every minute or so and was very annoying. I read Chris Ryan's SAS fitness a couple of years ago and it suggested that you could exercise vigorously until hitting a target heart rate, and then 'rest' for a bit, before bringing yourself back up to your target heart rate. I need to do some research as there's a lot of conflicting info about heart rate zones, but this could be a useful feature.

While Sleeping
-There is an option to sporadically check your heart rate while sleeping. This promises to provide more detailed sleep tracking, at the expense of a bit of battery. There is no visual difference to the sleep graph.

User Activated
-You can use the app to ask the band to check your pulse whenever you like. I've had a few erroneous results but on the whole it's accurate.

If you are not going to run with your phone (and you are not bothered about more accurate sleep tracking) I would suggest either not upgrading or buying a generation 1 mi band. You can check your pulse using your smart phone camera and an app (I use instant heart rate for android, but there's a plethora of options) Not upgrading will afford you better battery life.

I have two of the old version of these.

The pedometer isn't very accurate and one of them died completely after a couple of months. It kept a charge less and less each time until it did. The other is still going.

HR is constant in running mode only (Android, iPhone app to be updated). It won't give you a graph but an average at the end of the run / walk but during the exercise its have a live real time view.

I had this. Very inaccurate. Not constant monitoring of heart. Uses app for you to press for heart rate. You can presses twice in a row and get wildly inaccurate readings. Got a refund through PayPal as gearbest would not communicate.
After sync the time was 20 mins ahead of the app. Complained but apparently not an issue.
I wouldn't buy again.

These are great even if you just wanted a silent alarm to alert you without disturbing others

Ordered one this morning, getting cold votes - am I missing something here????

I have one of these - great for the price.

I have this, it works very well. Information on sleep tracking, daily steps taken, distance walked, calories and grams of fat burned are pretty good.
However points to consider:
The HR is on demand only
The calories and fat burned via any exercise that does not involve walking/running such as resistance, HIIT exercise cannot be recorded due to type of HR sensor.
For the price it's extremely good.