MC70 Low battery shut down

When the voltage reaches a certain level on the MC70 (at approx 22% capacity for a 1x and 11% for a 2x), voltage to the radios will be disconnected and the terminal will suspend.  This leads to a customer perception that they are being deprived of usable battery capacity.  Can you provide a customer facing statement regarding the reasons for us implementing this behaviour please
Christopher Paul
The purpose of disconnecting

The purpose of disconnecting all the various terminal functions at 11 or 22% is related to the preservation of memory backup time when a user is not able to cradle the device quickly.   The requirement is a legacy feature of MicroSoft’s mandate to backup RAM in these cases for many hours (actually several days).  Symbol’s MC70 development team made the conscious decision to maintain this legacy feature as it would benefit the majority of customers.
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Christopher Paul
Unfortunately, the software

Unfortunately, the software in the MC70 does not allow this.
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Christopher Paul
Unfortunately, the software

Unfortunately, the software in the MC70 does not allow this.
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Colin Gibbs
Chris, David, Thanks for the

Chris, David,

Thanks for the responses.  Field opinion based on customer feedback is that the amount of time RAM needs to be maintained for should be user configurable, especially given the persistent store architecture of WM05.  Other WM05 devices on the market implement this.  I will raise a GRIP request.

Colin

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Bo Nielsen
I agree with Colin! Customers

I agree with Colin! Customers are demanding that they can configure this. I have created GRIP 4213 for this

Bo

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David Meyer
Even though your data is now

Even though your data is now stored in Persistent Store (Flash), applications are running run in RAM and still have data in RAM.  This means that if we do not suspend early on (with enough battery power left) we have the potential of loosing data that has not been written into files.  It is still very important to suspend early to provide the customer enough time to all the terminal to suspend properly and hold data until the unit can have a new battery or go back into the charger.

I'm not a hardware person, so I could not tell you about lengths of time that we can last for a certain battery capacity, but even though we are using persistent storage, the battery level that we suspend at must be the same as when we did not have persistent storage to prevent warm boots from happening.

-Dave

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Colin Gibbs
Dave, Understood - it is

Dave,

Understood - it is still imperative that we maintain RAM - the point is, how long for?  Some of our customers are telling us that they want to decide that time, and are asking us to make this configurable, as some competitive products allow.  Most of our customers will get the terminal to a charger in considerably less time than 72 hours.  Of course it would be necessary to give warnings regarding loss of data if we did implement this as a configurable feature.

Colin

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David Meyer
Colin, I understand the

Colin,

I understand the customers' request, and why they would like to do this, but a "length of time" setting for how long the battery will last is very difficult to setup, and especially difficult to be acurate.  Depending on the current drain of the system at the time battery capacity is being checked, the actual battery capacity may be different than what we are reading in.

A lot of work as been done by the platform team to determine the approriate levels needed specifically needed for approximately 72 hours, and could not reasonably figure out all the values for every single setting a customer may want.

Also, I believe that the decision to suspend is done by the power micro, not by the OS, and thus a simple setting like a registry key change and a relatively minor driver change would likely not be an option.  It would probably take a large design change to make this feature.

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Charles Worm
We have similar discussions

We have similar discussions with several partners/customers in our region (Benelux : Belgium/Netherlands/Luxemburg).

First of all it is difficult to set the expectations right regarding battery capacity. Further it is a challenge to reach the 72 hours of Battery usage in Suspend mode. You have to do various types of finetuning to get the 72 hours goal. (Shutting down all the radio's, Switch off the Today wake-up, Max power safe, so in real life 72 hours is difficult to reach.

Their is also a lack of Whitepapers/Tips and Tricks how to finetune the MC70 for optimal battery usage (Symbol UK, Paul Hurford is working on it now) and their is lack of hands on training to SE's, Partners and customers to make them aware of the battery limitations. (There is a 2 days SMDKitchen course which hands on tips and tricks, but at this moment only available in the US. We are working on to get this one to EMEA).

We are also looking for a Solutions Center in EMEA where a partner / customer can test their application. (No formal statements yet if this is available in EMEA.

 

If we can set the expectations right, Advise customers how to finetune the MC70 (after the right trainings and with the right documents) we could make good progress.

KInd regards

Charles

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paul hurford
Hello Charles, The document I

Hello Charles,

The document I have put together (with Colin Gibbs) will focus why it is important to manage the sub systems of the terminal correctly i.e. radios, backlight, CPU.  The aim is to post something to DevCentral at the end of the week.

When you are in suspend mode there is very little if any thing you can do in the application i.e. the terminal has hit the critical suspend so all the battery is doing is keeping the RAM powered, all other sub systems should be off.

If it is important for your customer to hit 72 hours when suspended what you could do is ensure that the application closes down the terminal before you get to the critical suspend - so that more power is available for powering the RAM, this should be straight forward to implement.  All you need to is calculate how much power is used in suspend mode - which you can do.  But also take into account as the battery ages the actual capacity of the battery will slowly decrease.

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Bo Nielsen
I don't agree that we need to

I don't agree that we need to maintain the RAM as my customers use a database which stores all data in flash thus a cold or warm boot will not harm them in any way however being able to use only 78% of the already very limited battery resource does.

The RTC is lost on cold boot but that will need to be taken care of in a program or script (using NTP) anyway to secure a stable enviroment.

Bo

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Torben Mann
Does anyone have any

Does anyone have any additional updates on this?  

Bo's grip request (GRIP4213) is "under review" 

We have 2 customers in the West at the moment that is also upset over this early shut down of the device and would like it to be a configurable parameter.

Please let me know if anyone has any work-arounds for this?

thanks

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David Stern
In addition to RAM backup,

In addition to RAM backup, the RTC will also be maintained for several days.
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paul hurford
Hello Charles, The document I

Hello Charles,

The document I have put together (with Colin Gibbs) will focus why it is important to manage the sub systems of the terminal correctly i.e. radios, backlight, CPU.  The aim is to post something to DevCentral at the end of the week.

When you are in suspend mode there is very little if any thing you can do in the application i.e. the terminal has hit the critical suspend so all the battery is doing is keeping the RAM powered, all other sub systems should be off.

If it is important for your customer to hit 72 hours when suspended what you could do is ensure that the application closes down the terminal before you get to the critical suspend - so that more power is available for powering the RAM, this should be straight forward to implement.  All you need to is calculate how much power is used in suspend mode - which you can do.  But also take into account as the battery ages the actual capacity of the battery will slowly decrease.

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paul hurford
Hello Charles, The document I

Hello Charles,

The document I have put together (with Colin Gibbs) will focus why it is important to manage the sub systems of the terminal correctly i.e. radios, backlight, CPU.  The aim is to post something to DevCentral at the end of the week.

When you are in suspend mode there is very little if any thing you can do in the application i.e. the terminal has hit the critical suspend so all the battery is doing is keeping the RAM powered, all other sub systems should be off.

If it is important for your customer to hit 72 hours when suspended what you could do is ensure that the application closes down the terminal before you get to the critical suspend - so that more power is available for powering the RAM, this should be straight forward to implement.  All you need to is calculate how much power is used in suspend mode - which you can do.  But also take into account as the battery ages the actual capacity of the battery will slowly decrease.

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Christopher Paul
There are no work-arounds,

There are no work-arounds, sorry.
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Anonymous (not verified)
Why we can't change this

Why we can't change this setting in MC70 and we can do so in MC75?
In MC75 we have RunTime OPTIONS
Option1: Minimum
Option2: Less
Option3: Normal
So we should be able to do same thing in all other products.
Any news on this?

Regards,
Gustavo,
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