Slow battery charge

HP Business Notebook 8540p, Windows 7 Ultimate 64bit. I just got it about a month ago. I've already had HP send me a replacement battery for a strange charging problem that I'd like the community's opinion of:

The battery charges REALLY slowly while the notebook is on; the Windows power plan doesn't matter. By "REALLY slow" I mean about 10%/hour. This happens using the AC adapter or while docked. When the laptop is not turned on, it charges much faster, but I haven't measured that, exactly.

Like I said, I tried a new battery just a couple weeks after receiving shipment of the notebook, so I don't think it's the battery. Could it be that I have a bad notebook mainboard? What do YOU think?

 

Could be the power adapter is not able to provide enough current to run the notebook and charge the battery at the same time?

Maybe a better power adapter would solve the problem?

 

Download "BatteryBar" and see what it's estimate of your power usage is while this is happening. It's a crude number, but it may provide some insight.

 

Moral Hazard: after I made my original post, I scoured NotebookReview for more information and found that it probably IS due to the power adapter (dock or stand-alone) not being powerful enough. Easy enough to experiment with.

XGX2007: BatteryBar is awesome. Lots more info than the dumb HP Battery Check tool my vendor keeps having me report on; that tool sucks. BatteryBar is much more clear and verbose. LOVE IT.

 

I try to avoid running a laptop while charging. The laptop generates heat while running and the battery generates heat while charging, extra heat is not good for your new battery. Give it an hour or two while charging, depending on how low the battery was before you power it up or don't run anything that demands extra power, CPU usage. A scorching hot AC adapter is not good and it's not going to last.

 

My acer's power-brick has been too hot to hold for the last 4+years and isn't showing any signs of quitting

 

But that is still bad. Consider yourself lucky.

 

What?? Don't use the laptop while charging it? And vice versa? I... I guess, but what about when it's docked? Heh... now that I think about it, since it's charging so slow, I'm basically already doing this! HAR!

 

If you want to upgrade your battery later from 6-cell to 9 or 12 you have to remember how much power your AC adapter was meant to output.

 

TBH, that's something I've never noticed, or looked at. Usually if it charges, or the light that says it's charging comes on, I don't really look further into it..lol. I'll have to make a point to look into that from now on.

 

OP that does seem slow but moral got it on first response. You should not give MFG too much credit for matching adapter and notebook. It is a mismatch unless you find another reason.