Drill / Power Tools / High Drain cells in Laptop batteries?

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Sin su chon

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Jul 30, 2021
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I have seen discussions about replacing power tool high drain 3.7v Li-ion cells with laptop batteries NOT being a good idea (low power drain 3.7v cells in laptop packs). But what about replacing laptop battery cells with power tool cells? Please also comment about issues regarding power tool batteries taking a lot of abuse if heavily used, also if it's a good idea to salvage from a bad battery pack which might contain good cells but also very badly damaged cells (shorted, under voltage etc). Did the BMS "protect" the "good" cells that still test ok? Lastly, the cells do have to match the battery voltage design, either 4.2 or 4.35v since some laptops do not charge to 4.35v and will be stuck charging forever a 4.2v since it's never going to reach 4.35v. Comments, corrections, advice anyone?
 

Korishan

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what about replacing laptop battery cells with power tool cells?
This would be perfectly fine. The cells would actually benefit from this as they wouldn't be abused.
 

hbpowerwall

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This would be perfectly fine. The cells would actually benefit from this as they wouldn't be abused.
Except typically the trade off is less capacity unless they are good braned powertools
 

Sin su chon

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Except typically the trade off is less capacity unless they are good braned powertools
I've salgaved green Sonys 2,000 mAh, Samsungs 2,000 mAh, and red LG's 2500's, all from RYOBi18v and 40v power tool battery packs! My concern is that some 18v packs contain a few shorted/very low Voltage cells, and in some of the 40v packs, one sided had all 10 cells shorted. All the rest tested great at 4.10V + and internal resistance was low (20-40 milliohms). Should I assume these good cells were individually protected that's why they survived whatever the damage the pack went thru?
 

hbpowerwall

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Voltage isn't a good test of how much capacity is left & resistance is guesswork if you don't have a quality tester. Get your self an opus tester and see what they really have left in them.
 

Korishan

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