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Ollie222 · 12-15-2009, 10:10 PM

Hi,

I've just installed the latest version of battery bar on a Dell XPS 1645 running Win 7 64 bit and all seems ok except for the mWh figures seem to be out by approximately a power of 10.

It's reporting the battery as having 7800mWh when the battery is supposed to be an 85Wh one (85000mWh).

The percentages seem correct compared to the stock battery meter so I presume the actual figures are just being incorrectly.

It's not too important but thought you may like to know.

Cheers

***Chris*** · 12-16-2009, 03:52 AM

This issue has been reported before. Most batteries report their actual values when queried about their capacities. Some, however, provide values that need to be multiplied by 10. Basically, I just need to figure out a way to query the battery's multiplier value, which is normally 1.

The 7800 mWh report may be due to the fact that the battery has lost some capacity over time. Check the Battery Wear value for the design capacity of the battery and how much it has lost.

Ollie222 · 12-16-2009, 07:41 AM

Thanks for the reply and explanation. The wear indicator is 0% of 7800mWh and the laptop is about a week old so I presume there is currently no where.

Now I know for sure it's out by a factor of 10 it's not a problem but let me know if you want me to test anything.

acaurora · 12-19-2009, 12:39 PM

I am also having this issue, however I have an XPS 1640. What I am trying to figure out is that I think it is an issue on the hardware level, because I have tried using another tool (Lavalys EVEREST), and it reports the same 7800mWh capacity, with about 12.500 Voltage... so maybe its a hardware thing?

acaurora · 12-19-2009, 04:07 PM

I believe I have figured out what the issue is. From Googling "dell 85Wh battery 7800", I am seeing a lot of the 85Wh batteries listed with a 7800milliAMPhour. So what is happening is that the battery is reporting back the current, not the wattage it seems ?

What do you guys think?

***Chris*** · 12-19-2009, 07:02 PM

That could be true. Most laptop batteries put out somewhere around 11 volts, so that would turn 7800mAh into 85,000mWh, more or less.

acaurora · 12-20-2009, 02:44 AM

Is there going to be any future releases that can detect/fix this issue?

***Chris*** · 12-20-2009, 03:59 AM

I have no idea how to detect if a battery is reporting Ah or Wh. The specs clearly state that batteries should be reporting mWh. I'll need to do some research on this first before I can commit to it.

KX36 · (This post was last modified: 01-02-2010 08:54 AM by KX36.)

I've got 2 dell batteries, one is 56Wh, reports 5200mWh, one is 85Wh, reports 7800mWh. My laptop's a Dell studio 17, but the 85Wh battery's essentially identical to the Studio XPS 16 one from the thread starter.

The rated voltage is 11.1V, so I would definately say the battery's not following conventions and reporting mAh. Everest and another little thing I downloaded called "battery eater" report the same 7800mWh. (Interestingly, they also report the current voltage as 12.5V as acaurora did, not 11.1. wonder why)

***Chris*** · 01-02-2010, 04:14 PM

11.1 might be the minimum operating voltage. All batteries start at a high voltage when they are at 100% and the voltage drops as it gets down to 0%. On my old Palm Pilot you could get it to show you the current voltage rather than percent, so you could watch it go from 4.1v down to about 3.3v before it died.