Battery Will Not Charge

[hermanj04]

A few weeks ago, the hard drive controller chip on my Dell Latitude D820 went out. I purchased a new motherboard for it and replaced it. The laptop boots and works fine with the AC adapter, but the battery will not charge. Knowing that the battery is over 3 years old, I figured it was time to replace the battery, so I purchased a new one. However, the new battery will not charge either. The AC adapter is good, as it will charge the battery on my friend's D530 just fine, so I don't think it is the problem.

I am assuming that it is either the new motherboard or battery that is bad, but I don't know how to tell which one it is without purchasing a replacement for one or the other. Does anyone have any suggestions on how I can test these? Or is there something else I might not be thinking about that could be the problem?

 

[SchizTech]

Dells are very particular when it comes to charging the battery. There are more moving parts when it comes to Dell laptop charging than battery and adapter. The Dell charger has a chip in it which identifies it as a proper Dell adapter to another chip in the motherboard - if the adapter isn't recognized as a certified Dell adapter of the same family the laptop was designed for the battery won't charge.

What you can do to get a better handle on the issue is boot into the BIOS (F2 on bootup), where there should be a section that displays charger and batter info. If the laptop correctly identifies the charger, it will read "65 W Dell charger" or somesuch (may be a different wattage value though 65 is common). If the display reads "unknown adapter" that tells you the laptop isn't identifying the charger. Also there should be a display of battery health. If the battery health reads OK, that's not your problem.

There are two possible reasons the Dell won't identify the charger properly: the chip in the adapter is bad, or the chip in the laptop is bad. Some Dell laptops have a separate charging board, in which case that part could need replacement. IF you don't see such a daughterboard, it's in the mainboard. Did you replace the motherboard yourself or send it out/have a shop do it? If the board can still be returned to the seller you may want to consider it. Where I work we have lots of Dell chargers to test with - we know it's the laptop and not the charger when the BIOS won't pick up any Dell charger we try.