Bogus battery ratings?

Just received an extra 6 cell battery for my XPS, and noticed something funky. The website lists it at 56Wh and the label says the same. Dell Support Center and Battery Bar both show that the actual design capacity is 52Wh. ?

So...I checked the 9-cell battery that came with the laptop. Website and packing slip both say it's a 92Wh battery, but Support Center and Battery Bar both say actual design capacity is 84Wh.

I feel like I've been robbed! Lol, seriously though are mfg's now listing battery ratings with over inflated numbers the same way hard drive manufacturers have been doing for years?

Would some of you mind checking and see what your labels say and if the software agrees with the marked rating?

Thanks!

 

Not sure how they do it with batteries, but with hard drives, 1 marketing megabyte is 1,000,000 bytes. An actual megabyte is 1,048,576 bytes.

When you add that up over the course of say, 500 gigabytes, the disparity is obviously noticeable.

 

Oh yeah, if I had a dollar for every time I had to explain that to folks, I'd be able to retire...

Just got off the phone with Dell, their take was that the software is wrong (geez). Well at least on the 9-cell it's clear that the battery is not what it is advertised to be (90 vs 92). I could probably live with that minor difference, but 84 is a much bigger difference, and to make it worse I only really get 81Wh fully charged (yeah I know batteries wear, but this is a week old). I've gotten up to 6 hours off that battery at 81wh, so a true 92Wh would net about 45 additional minutes. That's a huge difference.

Anyway, they are escalating it to their Level 3 reps and say they'll call back in 2-3 business days. I'll give them that, and I hope they open their eyes as I don't really want to send the laptop back for freakin' batteries of all things.

 

Just checked mine, same deal. Dell support center lists it as an 8.40Wh battery with a total capacity of 8.10Wh Kind of a bit misleading on Dells part in my opinion. I don't really see anything wrong with the battery life of my system, but they do advertise it as a 92Wh battery, not an 84Wh battery.

 

I'm more used to Dell doing the opposite. They tend to "overcharge" batteries to offset the appearance of loss of permanent battery life and increase the odds of the battery being bad after the 1 year battery warranty ends.

 

?? u got 6hrs off that 9 cell~
i hardly touch 3hr with 1st gen intel..lol

 

I hope that isn't true. My Inspiron 6000 has lasted on the same factory battery for over 6 years now. I bought an extra Dell 6 cell for my XPS just in case I'm out and about and need extra juice. These laptops just seem to draw so much more power than before. You would think the technology for batteries would somehow keep up with the demand for power thirsty laptops, but maybe that's a marketing scheme.

 

Yeah, 5.5-6hrs is decent, but if it was actually capable of 92Wh it would be even better by 45 minutes to an hour.

Has anyone received a 9-cell that actually is capable of 92Wh? Some google searches bring up references to earlier Dell laptops that came with 84Wh batteries...I wonder if they were simply rebadged at the higher spec and are being sold to clear out old inventory? I notice that the item numbers you can purchase online don't match the item numbers that are actually shipping with the laptops, either.

 

I love my battery life just wish they would wise up and some how make it small like macs are.

 

Would you mind checking the label on your battery, does it say 92Wh or 90Wh? Also, if you still have the Dell Support Center software installed, would you mind checking what it says is the design capacity of your 9-cell?

 

Mine says 11.1 V/90 Wh, Type R795X. Dell Support Center reports 8.4 Wh total capacity and 8.01 Wh effective capacity. This capacity is confirmed by HWiNFO32.

Now, Support Center also says that the voltage is actually 11.79 V. I wonder if that has something to do with the difference? I'm not remembering enough of my electricity material from college.

 

Thanks for checking, that's the same type and other info as mine. I wondered about the voltage too, as mine was 12.98v. Obviously I can't be certain, but I don't think actual voltage affects the "designed capacity" numbers. I was running on AC at the time and had other things running in the background, I sort of assumed it was reporting the actual voltage being drawn, not the battery rating. If the voltage was a factor, I think your system and mine would report different capacity.

Anyway, thanks again for having a look!

 

The voltage is actually directly related to charge, I just read up on it... Mine is 12.99 V at full capacity. When the voltage reaches a minimum level, the battery is considered "discharged."

 

Makes sense, thanks for the info!

 

So it turns out Dell is playing loose with the numbers to come to the 92Wh rating. Tech support called back and confirmed that they were going with the "blame the software" story and that the battery was, in fact, a 92Wh battery even though all indications were to the contrary. I asked how the engineers actually determined that it was the software that was at fault, but the gentleman could not provide an answer.

After I got off the phone, I was looking at the battery again and I noticed there is an amperage rating of 7.65Ah. If you multiply that by the 11.1v nominal battery voltage, you get 84.9Wh...pretty close to what the software is reporting. Dell Support Center indicates a fully charged battery is 12.98v, multiply that by 7.65Ah and you get 99.3Wh. If you average the two results, you get...wait for it...92.1Wh. Numbers come fairly close for the 6-cell battery as well.

Kind of cheesy, definitely misleading IMHO. Oh well...

 

Haha wow. Good find.