Slice Battery Problem

Hi all,

I posted a couple of days ago in the M4700 Owners Thread: http://forum.notebookreview.com/del...82758-m4700-owners-thread-69.html#post9133679

Could anyone with a slice battery (ideally with a M4700) please check whether their CPU speed is restricted when running off (discharging) the slice battery.

My issue is that when the slice battery is being used (away from AC) my CPU will only run at 1.2GHz idle speed. It is fine running off the standard battery so is not software related.

The response from Dell has been to arrange for an engineer to visit later in the week to try another slice battery and, failing that, replace the mainboard. Given the newness of the laptop, I am loathe to allow a mainboard swap until I know for sure that there are people running M4700's with slice batteries and no such issue.

Annoyingly, my slice battery works fine on a colleague's M6600, but I realise that the systems are different. Amusingly, the slice battery purchased did not list the M6600 as compatible when I checked (after running the test, whoops!). In fact, I cannot find a slice battery listed for the M6600 at all.

Thanks,

Martin

 

Interesting.

So it works fine on internal battery but throttles down when it switches over to external/Slice battery? Sounds like its maybe not getting enough juice?

Anyway, now that you mention it, I guess I need to check mine as well. I installed it briefly for functionality, but never ran a full timed systems check.

I really hate doing that stuff, but know it has to be done. Don't want to really need it and it not work. Or work for a short period and then quite.

 

Sorry Krane, I somehow missed your reply. I see you have the M6700 whereas I have the M4700, but I would still appreciate you testing your slice battery for me anyway. I realise it will probably work fine on your system (it works OK on a colleague's M6600) but in case it doesn't it is more evidence to go back to Dell with...

They are still insisting on wanting to swap my motherboard. Given I've had confirmation from another user on here that has found the same, this seems like a total waste of time / money / effort when I am positive the issue is firmware (I can actually get full speed temporarily - between reboots / suspends - with a software hack but don't want to mention any more until I know from Dell what is going on).

Thanks,

Martin

 

Have you tried a different mains adaptor? If the one you are using has insufficient capacity these machines scale down the CPU speed as low as it will go, perhaps it is struggling to charge the two batteries at once? The M6700 usually comes with a monster 180W pack though!

 

What exactly is it you wanted me to test for, CPU throttling? What are you hoping to determine? Yes, if it's do the batteries work.

 

Could you test for CPU throttling when discharging from the slice battery. Boot with charged slice battery and without mains adaptor (you can also remove the normal battery if you want). Assuming you run Windows, select the High Performance power profile to ensure no software throttling. Then, load the CPU with your favourite program (IntelBurnTest, Prime95 etc.) and monitor clock speed with another favourite program (HWiNFO, CPU-Z etc.).

On my M4700 the CPU is throttled to the SpeedStep idle speed of 1.2GHz when running from the slice battery. Doing the exact same test but running from the normal battery I get no such throttling.

As you have a M6700 this is more out of interest for me. However, if your machine shows the same throttling, at least we have shown that the issue is even more generic than just the two M4700 laptops I know of (mine and one other user on these forums). If it happens on the M6700 with slice battery as well, then Dell cannot tell me the issue is my M4700 motherboard.

Thanks,

Martin

 

Very busy schedule at the moment, but will try and get to it tomorrow morning.

 

Many thanks. I appreciate you taking the time and I look forward to the result

Oh, would you also be able to tell me the model number and Dell part number of the slice battery you have? Mine appears to be "type KJ321" and "DP/N 0UJ499" with a date of "2012 / 07". I just want to check that they did indeed send me the correct model for the M4700 / M6700 series.

 

CPU @ 1.5 GHz

 

Krane,

Many thanks for testing this. So that I can be absolutely sure of the information that I pass onto Dell, could you please confirm the test conditions... that is, your CPU throttles to a Maximum of 1.5GHz when discharging from the slice battery under the following conditions:

----
1. You are using High Performance profile in Windows (or another profile that does not restrict CPU speed).
2. You load / stress the processor with software, e.g. Prime95 or IntelBurnTest, whilst monitoring the CPU clock speed.

and that:

3. Performance of the CPU is consequently much lower on the slice battery than if using the standard battery for the same test conditions.
4. The CPU is allowed to run much higher on the standard battery with no changes made to the system or power profile.
----

Finally, which CPU do you have? Is 1.5GHz its lowest normal state? (My 3740QM uses 1.2GHz as its idle speed.)

Looks like Dell have made an oversight on the M4700 and M6700 with respect to the slice battery usage. Annoying that my colleague's M6600 does not throttle at all when running from my slice battery!

Once again, many thanks for checking this for me.

Martin