Li-ion Power tool batteries

LED Monkey

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I've got a Porter Cable drill battery that's dead, my question is do they usually have a BMS inside them?
Kinda thinking of taking it apart and replace the li-ion cells inside it. How else would the cells charge evenly on the charger?
 

coffeecup66

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My question to you is : do you think they could be [legally] sold on your market without a BMS ?

Cheers.


PS: what voltage is your battery ?
 
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LED Monkey

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Obviously in my post I "did" think they have a BMS inside them, but was not sure if there was something more to it.
So it seems it would be a simple swapping of a few cells and soldering. I've not had the need to do this before.
It's a 20V.
 
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coffeecup66

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It's just to clarify a forum thread for readers. I figured you knew it had BMS.

But have you checked for low voltage in your "dead-ish" battery ? (before going to the lengths of tearing it open and replacing/resoldering all that nice stuff)
 

LED Monkey

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It will not take any charge at all, It's 1 of the 2 that came with the drill, If I do take it apart I can check each cell for there condition. If I go ahead and replace the cell it would be all the cells for obvious reasons .
 
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coffeecup66

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Ok. It could be that your battery just has an 'under-security-threshold" voltage and thus, your charger refuses to charge it.
 

LED Monkey

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Well I guess I could remove the cells and try to charge each one separately . It might bring them back up to where the charger would charge them again.
 

LED Monkey

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Local yes, recently not really , maybe 3-4 years ago. And I do think it's probably 1 bad or too low of voltage cell in the pack.
 

coffeecup66

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NB: Disclaimer: posted for entertainment purposes only.



If you got it recently in a local shop, take it back to the store with your receipt and ask (after faulty demonstration if needed) for a replacement or a refund.

(Edit: guess I wrote the above line while you were posting your last answer ! )
 
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LED Monkey

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I've read threads of doing this with "single" cells but I didn't think about doing this with the battery pack. Thanks I'll give this a go.

PS. Should I tell my attorney coffeecup66 said it's ok? :twothumbs just kiddin.
 

orbital

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I'v done NiCad setting 'trick' to a couple Li-Po batteries; that were over discharged & weren't recognized by my charger, at all.
Saved one of my expensive Li-Po battery & a friends.

If my lithium power tool battery wasn't recognized by my charger, I'd try give it a go for that too.
just keep an eye on it ;) (btw it's only like .1A in NiCad mode for 5~10 minutes, so you can then go to your normal charger)

It's not unlike a Manual setting on an old school charger, so to speak
 
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Lynx_Arc

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You can check the pack condition by measuring the voltage across the + and - pins with a meter. You need a torx with a hole in the middle to open the pack up and can test individual cells once you have it out of the case. I have one dead Black and Decker tool battery of which Porter Cable batteries are almost identical in the electronics and pinouts you can use 20v PC batteries in B&D 20v tools with a slight modification.
 

LED Monkey

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Yes it looks like security T bits to take it apart. They get ya pretty good $$ on OEM battery packs. It hasn't been used all that much, I hope I didn't put it away too low state of charge.
 

jabe1

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Most likely one cell is bad. I have two 9ah Milwaukee 18v batteries that have gone bad recently. After contacting them, they sent me two replacements.
I saw a vid on YouTube of someone breaking down a Porter Cable 20v pack; lg cells tab welded together and no protection circuitry. Should be possible to replace them, if you can spot weld the tabs.
 

coffeecup66

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I saw a vid on YouTube of someone breaking down a Porter Cable 20v pack; lg cells tab welded together and no protection circuitry. Should be possible to replace them, if you can spot weld the tabs.


Just so that there are no misunderstandings.


There is a big difference between "waking up" a "sleeping" battery pack, and taking a faulty battery pack apart and reassembling it with other cells.

The difference is serious potential liability.

Waking up a sleeping batt. pack is a function that certain chargers integrate.

Rebuilding faulty battery packs in your home, on the other hand, could make you an uncertified (and therefore unauthorized) battery assembler.


So I sure would like to see a video that shows a Porter Cable 20v pack with "no protection circuitry". :popcorn:
 
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orbital

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Forgot to mention this last night.
I did the Li-ion 'resuscitation' to a brand new Keeppower 26650*. Order a few & one was not charged up from the factory.
It did not get recognized in either on my lithium chargers, so I put it on a NiCad charger for a little while,, woke it up and finished it on my lithium charger.

all good


*I'll bet most people here would have fired back an email to the seller & yelling/demanding a new cell ect!!!
..instead of dealing with it.
 

LED Monkey

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Just a quick update on the power tool battery pack. The jump start method did the trick, I took a good pack and a couple jumper wires pos to pos / neg to neg 10 minutes later it would take a charge on the Porter Cable charger.
:twothumbs coffeecup66
 
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