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Need Help with Dead Laptop Battery

By jbraylor ·
Saw some good advice on trying to revive a "dead" battery. My battery is brand new, but I left it alone in storage for 1 year. It cannot hold a charge now. According to one discussion here, it was advised to put a 100 ohm resistor to the battery and bench charge it forcing current in battery. How do I do this? Do I take it to a specialty shop. Plese advise. Thks.

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by TheChas In reply to Need Help with Dead Lapto ...

To "bench charge" a battery, you need a DC power supply.
Preferably, one that has current limiting.

You adjust the power supply output voltage to match the charging voltage for the battery.
(Typically less than 1 volt above the "nominal" battery voltage.)

Then, connect the power supply to the battery through the current limiting resistor.
(Or, set the current limit on the power supply to 100 mA.)
100 ohms sounds like too high a resistance value to me.
For a 12 volt battery, I would use between 10 and 20 ohms.

Monitor the voltage at the battery for the first few minutes.
If the voltage starts to rise, the battery is accepting a charge.

So yes, if you do not have the tools or knowledge, you are better off taking the battery to a battery shop and see if they can charge the battery for you.
It is VERY possible that just 1 cell in the battery pack is bad. A battery shop should be able to replace a single bad cell for much less than a new battery pack.


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by TheChas In reply to

I fully agree with the comments that Guro Of DOS posted to your discussion on this topic.

It still would be worth the time to take the battery to a specialty battery store that has the capability to rebuild battery packs.
They should have the tools and knowledge to check the battery pack and let you know if it can be recovered.

As a side note:
Most battery packs will survive a year in storage IF they are fully charged before being stored.
And, immediately charged when removed from storage.


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by onthetrade In reply to Need Help with Dead Lapto ...

Fisrt off this is a very good question. I would not advise trying to force a charge into any laptop battery, I'm not sure who advised you to do so but the fact is that after about a year most laptop batteries will tend to die off. Trying to force a charge will most likely damage the battery anyways and give you little to no results in my opinion. You may also want to make sure that the laptop your using that is trying to charge the battery is contacting well and providing enough power make it charge. If no charge is getting through at all it will most likely be the fault of the motherboard. Good luck in any case!!!

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by wlbowers In reply to Need Help with Dead Lapto ...

You have a good chance that the cells in the battery pack have leaked. It that is the case even though is brand new it will have to be rebuilt.


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