Found a used 52v 21Ah Biktrix pack, it's been in storage without a top-up since August 2021...

[Klauts]

The pack supposedly never been used but it was stored a basement at full charge for nearly 2 years....

What are the chances the pack is still good and worth purchasing as a backup?

The seller isn't able to check what voltage it's resting at after all this time but the LCD on his bike shows it has full bars...

Any input would be greatly appreciated!

 

[Bbbbrass]

Should be just fine. May have lost a bit of capacity, likely around 5%. I can't find 52V 21Ah on a web search, I can find 48V 21Ah, or 52V 17.5Ah. How certain are you this person is truthful and the pack isn't abused?

I'd go for it, but I would be pricing the raw cells more than the pack. There are 68-78 cells, worth $2-3 each. In other words, I wouldn't pay more than $250 at the most for it. If you can go test it and make sure it works, maybe that's worth more then. I guess if you don't DIY batteries there is a premium also.....

Brand new on company website that battery is $700-$850. An AliExpress firebomb is $400. Good luck!

 

[amberwolf]

As Dogman has said, assume a used pack is worth nothing until proven otherwise.

And remember that the longer cells stay at full charge, the faster they degrade; how much faster is dependent on the cell and the environmental conditions, etc., so how much shelf life the pack has lost is unknown.

If it's cheap, it could still be a better option than many of the cheap no-name packs (like the AE firebombs noted above).

If nothing else, you'd use it till it dies, then you have a case, BMS, etc to have rebuilt into a new one.

 

[Klauts]

Should be just fine. May have lost a bit of capacity, likely around 5%. I can't find 52V 21Ah on a web search, I can find 48V 21Ah, or 52V 17.5Ah. How certain are you this person is truthful and the pack isn't abused?

I'd go for it, but I would be pricing the raw cells more than the pack. There are 68-78 cells, worth $2-3 each. In other words, I wouldn't pay more than $250 at the most for it. If you can go test it and make sure it works, maybe that's worth more then. I guess if you don't DIY batteries there is a premium also.....

Brand new on company website that battery is $700-$850. An AliExpress firebomb is $400. Good luck!

Thanks for the reply! I'm pretty sure he's being honest but no way to tell for sure... He showed me the purchase receipt so I at least know the battery is a Biktrix product legitimately...

 

[docw009]

The pack supposedly never been used but it was stored a basement at full charge for nearly 2 years....
The seller isn't able to check what voltage it's resting at after all this time but the LCD on his bike shows it has full bars...

The BMS is still active, so that's good. While there's been lots of talk about the perils of storing a battery at full charge, the worst case is in a hot ambient. In a basement, it's not too bad.

21Ah is a big battery and if you lose 10%, it's still a lot of capacity

I've got unused cells that I believe have sat for over three years at the shipping voltage of 3.34 volts. When I bought them, they were at least two years old, and they were at 3.34 volts. I used half of them, but have 48 sitting outside for the past 14 months, and still at 3.34 volts