This will stump you!

blueboxer
Full Member

Posts: 108

This will stump you! Jun 21, 2015 21:05:04 GMT -5

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Post by blueboxer on Jun 21, 2015 21:05:04 GMT -5

My wife has a Dell Vostro 3560 running Windows 7 Pro. Many weeks ago her screen went dim and the computer power inexplicably switched to battery. The power supply was plugged in, but on a reboot the diagnostic said it could not detect it.

We phoned Dell and they diagnosed it as needing a new motherboard and hard disc, which they quoted at $350 (US), data transfer to the new hard disc extra. We sought a second opinion from George (not his real name, which is Chinese and unpronounceable) who runs the local computer shop. He could find no fault, but removed the battery, plugged the computer power supply in, and it ran fine for weeks.

Eventually we turned off the computer, plugged the battery back in, plugged the power supply back in, and everything ran as it should for six or seven weeks. Then this afternoon for no detectable reason the screen went dim and the computer switched to battery again. My wife removed the battery, plugged the mains power back in, and the computer works fine.

The first time this happened we replaced the power supply, and the problem went away. Then it came back precipitating the actions listed above. When the screen dims the diagnostics say there is no power supply even though it is plugged in and working and will power the computer as long as the battery is out.

For what it's worth my wife turns on the computer for 3 - 4 hours in the afternoon, turns it off and restarts it for 4 to 6 hours in the evening. She uses it on her lap and has no heat problems.

So what on earth is going on?

What you don't know won't hurt you as much as what you do know that ain't so.

drcard
Software Review Panel

Posts: 581

This will stump you! Jun 22, 2015 21:00:12 GMT -5 ccbolt likes this

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Post by drcard on Jun 22, 2015 21:00:12 GMT -5

Hi blueboxer,

I'll try to explain. What you described is a very common problem with laptops and other devices that rely on rechargeable batteries.

All problems you described are a result of the rechargeable battery.

The plug into the wall adapter coverts the 120 V - 15 amp voltage from the wall current to the low voltage and low amperage needed by a laptop computer. The adapter prevents any higher voltage or amperage getting through to the laptop; thus, even when an increased need arises it can not deliver more than its rated output. When the rechargable battery developes what is called a "leak" (loses electrical charge when not in use), the battery needs to recharge to replace this loss. When the battery starts to recharge while in use, it diverts the electricity to it and thus doesn't leave enough electricity to go to the laptop. The laptop software can only tell that not enough electricity is coming in, thus the warning message. This is why unpluging the battery prevents the diverted electricity to the battery and allows all the electricity go to the laptop. Sometimes these rechargeable batteries will leak so bad as to divert all the electricity to it and prevent the laptop from booting at all. TIP # 1 for laptop users. If the laptop fails to boot plugged into the wall or not, remove the battery and try with the adapter alone before taking it to a shop.

The elvolution of these rechargable batteries is so much that it really does make a difference which kind of battery you use. Also any laptop over two years old will have came with a rechargable battery that does less than half of the ones sold today. If you plan on keeping a laptop for many years, then when replacing the factory installed battery (when it dies) don't buy a factory battery as a few $ more you can get a better one. Simple fact: rechargeable batteries last longer if they are not used to their maximum amperage. A battery rated for 4000 mA for a laptop needing only 2000 mA will last way longer (and give better service) than a battery rated for 2000 mA.

Why did the battery seem to work after non-use for so long? These batteries work using a chemical reaction to produce free electrons. These chemicals are suspended in a semi-solid material. Heavy use can cause the chemicals to be used up in the area where the reaction occurs. With time all chemicals will try to reach an equilibrium, even suspended in a semi-solid state (just takes longer). With chemicals in equilibrium the battery will work again. It won't work long as the total amount of the chemicals have decreased that caused the first shortage (and caused the leak).

I hope this answers your question.

Last Edit: Jun 23, 2015 20:28:04 GMT -5 by drcard

HTH, Dana:)) 👨‍🔬

blueboxer Full Member Posts: 108	This will stump you! Jun 23, 2015 19:38:02 GMT -5 Quote Select Post Deselect Post Link to Post Member Give Gift Back to Top Post by blueboxer on Jun 23, 2015 19:38:02 GMT -5 Wow,Dana - Knew I should have asked you first! My wife thanks you, and I thank you. And also thank you for being so prompt about it. "Bis dat quis cito dat". - bb
	What you don't know won't hurt you as much as what you do know that ain't so.

Post by blueboxer on Jun 21, 2015 21:05:04 GMT -5

Post by drcard on Jun 22, 2015 21:00:12 GMT -5

Post by blueboxer on Jun 23, 2015 19:38:02 GMT -5