What is the shelf life for lithium-ion batteries ?

[MowerMike]

One more thing to try, probably hopeless, but put some current into each cell with a charger that outputs around 4 volts for a couple minutes each. Then try your regular charger, if it sees some voltage on the pack it may actually recharge the pack.

It’s 10 cells in a 20 volt battery, so wouldn’t it be 2 volts. Perhaps you didn’t see my edited post. Anyway, I’m trying to get the eBay seller to accept a return.

 

[tom3]

Series: five batteries at four volts for the 20v output - parallel, two sets tied together for double the current capacity. But those are packaged pretty tight, oh well.

 

[MowerMike]

Series: five batteries at four volts for the 20v output - parallel, two sets tied together for double the current capacity. But those are packaged pretty tight, oh well.

Gotcha !

 

[bertsmobile1]

One more thing to try, probably hopeless, but put some current into each cell with a charger that outputs around 4 volts for a couple minutes each. Then try your regular charger, if it sees some voltage on the pack it may actually recharge the pack.

If you are going to try some thing stupid like this,
Do it outside on a concrete brick or steel surface with nothing flamiable nearby .
Lots of videos of people's garages / houses burning down because they managed to ignite the battery pack by incorrect charging .
Unlike a lead acid battery where you are just shuffeling lead between 2 valance states a Lithium battery under goes a complete redox reaction .
As the battery contains both the fuel & the oxidant, once they start to burn they can not be extinguised as several airlines found out the hard way.
You can toss them in a bucket of water and they will continue to burn under water

 

[Richie F]

You can solder the terminal strips. I have done it.
Many YouTube videos on doing that and making a simple spot welder also.
Buying a laptop battery to me is expensive.
Buying quality individual batteries to me is less expensive.
LG, Panasonic and Samsung are three that come to mind.
The ones from China don't cut it.

 

[tom3]

The ones from China don't cut it.

That's what I've found out over the years too, even with Nicd and Nimh. Factory seconds? Thirds?

 

[bertsmobile1]

That's what I've found out over the years too, even with Nicd and Nimh. Factory seconds? Thirds?

Yep,
Selling rejects as good parts did not start with CHinese Briggs carburetors, it has been happening for decades.

 

[wrldtvlr]

Selling rejects as good parts did not start with Chinese Briggs carburetors, it has been happening for decades.

And then there's all those pharma factories in India and China churning out our generic meds...

 

[tom3]

And the Chinese Flu pandemic and the half billion masks that we've imported from, you know, China.

 

[MowerMike]

So, today the seller of the defective battery agreed to issue a refund w/o having to return the battery. Since it was a free return, the seller would incur the return shipping cost and it makes sense not to waste money on something that they could not resell. Since I did not need to return it, I decided to open to see what I could find. What I found was that all pairings of battery cells showed the same 0.5 volts, or 0.25 volts/cell. I'm not quite sure why they should all decline at the same rate, but for sure they are bricked. I'm definitely not going to mess with this, and will drop it off at a battery store for recycling. Nor am I going to buy any more of these, since most of the remaining old stock are probably bad as well.