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Tagged: battery life problem
- This topic has 0 replies, 2 voices, and was last updated 6 years, 5 months ago by Anonymous.
Received my Mooshimeter today, It’s awesome!
What is the sleep current draw, and how much less is the hibernate mode draw? If the meter is in standard sleep mode (not hibernate), how long will it stay there on a fresh set of Alkalines?
Another question: Why didn’t you put the LED so it was easily visible from the front? The back bottom edge seems to be the worst possible location.
Last time I worked it out the current draw in sleep mode was on avg between 50 and 100uA. I need to work it out again, sorry I can’t remember where I put that figure. The main battery draw is waking up once/second to send out a radio packet. It worked out to about 2 years assuming a 2000mAh alkaline AA battery.
I haven’t run the figures for hibernate node, but I’m pretty sure it would hibernate for longer than the shelf life of the batteries.
The meter can measure its battery voltage and the iOS app displays it, that feature is still missing from Android though. When that’s added we can hopefully get some more insights on battery life in the field.
Re: LED location: In the beginning the plan was not to make the case transparent. This meant having the LED close to the surface was a good thing, and having it pointing straight back seemed like a bad idea, and I was trying to keep as few components as possible on the front because I wanted all the SMT done in one pass. If this gets revised the LED will move.
My 1st set of batteries died after use the meter for about 1 hour over the course of 2-3 weeks. I put it in Hibernate mode the 1st 2 or 3 times I used it, but didn’t bother the last time since the stand by power consumption was supposed to be so low.
How can I tell if the meter is on or in sleep mode?
Why did the batteries die so quickly?
I am wondering about a possible battery draining scenario?
I notice that if the app is closed (home button pressed or move to another app) there is not indication it is still active (some apps show a red bar allong the top of the screen to warn that an app is still churning madly in the background).
Thus the Mooshimeter still shows high activity when I think I have shut it down. Oven closing the cover of an iPad allows it to continue. Only when actually removing the app from the active list actuall breaks the data stream.
Not sure how much drain there is in this mode? But I would imagine forgetting to do a complete shutdown would also put a drain on the display device.
Sorry, just musing about this without taking any readings. (Can the mooshimeter be used to measure its own current draw?)
Sorry, fell behind in the forums!
You’re right, the batteries should not have died that quickly. Hibernation should not be necessary.
The meter is in sleep/standby mode whenever it does not have an active bluetooth connection. When the meter is connected, the LED will be flashing every time it takes a sample, which is several times a second on the default settings. If the meter is in standby it will only give a very small flash every 10 seconds.
Was the meter connected the whole time? If connected the battery life of the meter is much shorter.
You can disconnect from the iOS app by pressing the “back” button in the top left corner of the text view page. Pausing the stream when the app is backgrounded is already in the feature requests on github, will try to push that soon.
Just wanted to follow up in this thread to say I found a bug in the production firmware that raises the idle draw by a factor of 10 or so. It’s fixed in the latest firmware version, you can see instructions in the blog here
Hi! Just received my new Mooshimeter. Loving it so far!
Question: I noticed that, in Idle mode (after pressing the “disconnect” (two plugs together) icon in the android app), I don’t see the LED light at all. However, when I put it in hibernate mode, I see the LED do a rapid-fire-burst pulse about every 10 seconds.
This is with the latest firmware and android app from the Google Play Store.
Is this LED burst every 10 seconds, while in Hibernate mode, normal?
Yes, this is normal – the meter is waking up to measure the resistance port while hibernating. Some of the documentation is out of date regarding LED behavior.
Also note that you don’t need to put the meter back in to hibernation after you finish using it, you can just close the app. The meter’s batteries will last over a year while advertising over Bluetooth. We’re changing the name of “hibernate” to “shipping mode” soon to reduce confusion.
Unfortunately I am having very poor battery life after several different sets of new, quality AA alkaline batteries (Duracell, etc.). For the last set I marked the install date (July 4th, 2016) and today they had to be replaced. I have used the meter briefly at most a few times during that interval.
I measured the active current (connected to the iOS app) at about 10 mA (average). Power is from a bench supply set for 3.0V. If I close the app (using the Back button) the current draw drops down to an average of 2.2 mA. The LED blinks rapidly every 2 seconds or so in this mode.
2+ mA with decent AA Alkalines would last about 30-40 days which matches my experience.
What’s up with my unit? It falls far short of the expected long battery life while it’s idle. Very annoying to change the batteries every month or so. Something is not right.
Appreciate any help you can provide. Thanks – Duncan
OK. I think I’ve resolved my battery life issues which seem to be directly related to having an SD card installed (earlier current measurements had SD card installed). When I remove the SD card then the idle current drops down to ~125 microAmps. Much better and should get over 1.5 years from a 2000 mAHr AA battery. That all makes sense.
Since there is no way to install as SD card with opening up the unit (I understand why that is necessary) I have just left it installed. Not anymore. You can either open the unit to remove the SD card or to replace batteries. Your choice!
Maybe it’s already there and I missed it but since this has such a huge impact on the idle battery life it should be clearly stated in the manual, app help page, etc. Even better to have a reminder notice if possible when the app is closed and the SD card is present.
Ideally the SD card would be powered off while idle but I assume that would be a hardware change. Something to consider for the future….
I think I found the issue you were experiencing and fixed it in firmware. The SD card is still the biggest power consumer in the device (when logging every second), but its current consumption is vastly improved in latest firmware version. I am using version 1470628829 for reference.
my mooshimeter was shipped with a dead battery(one cell had 1.2V and one had 0V).
I inserted new ones but they only lasted for two days with a logging interval of 10 seconds.
Four days ago I inserted a different brand, but it did not last until today(without logging, no bluetooth connection).
I did not measure if the new batteries also had this strange fact that only one of them is empty.
Do you have any idea why this happens?
There is known problem with battery holders. Some of them might have sharp edges or burrs, which can cut trough insulation of battery. In that case, battery would get very hot, as it short circuits. (Actually it only happens at negative holders)
So, you should check if there is some burr or spike etc at any of those holders and then carefully smooth it by sandpaper/file/knife/something. My mooshimeter did not have any symptoms of that problem, but still i found quite sharp edges, smoothed them and covered those holders with kapton tape (very thin electricians(?) tape).
There might be better ways to deal with it, or just simply put the batteries in the meter very carefully, but check for the burrs in any case.
Hi Patrick and ville,
I finished writing up the battery issue and taking pictures. You can see it here:
I tried to come up with as simple a solution as possible for fixing it, and just rubbing the contacts with a steel tool with some pressure fixed it on my sample meters here. I even used a fork on one contact as a test and that seemed to work.
Thank you for helping to document the problem, and sorry for the trouble. Best
I have an solution heat shrink.
I did put heat shrink over all holders just to make sure not to have this problem anymore. I have 2 mooshimeters which have both the same problem and drained the battery even in hibernation empty one in 3 weeks the other one in hibernation in 6 month.
They both arrived with 50% charge in the battery and I first blamed DURACELL.