Li-ion Power tool batteries

LED Monkey

Enlightened
Joined
Apr 25, 2016
Messages
281
Location
Massachusetts
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

Enlightened
Joined
Dec 16, 2016
Messages
219
Location
Cafner
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 ?
 
Last edited:

LED Monkey

Enlightened
Joined
Apr 25, 2016
Messages
281
Location
Massachusetts
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.
 
Last edited:

coffeecup66

Enlightened
Joined
Dec 16, 2016
Messages
219
Location
Cafner
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

Enlightened
Joined
Apr 25, 2016
Messages
281
Location
Massachusetts
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 .
 
Last edited:

coffeecup66

Enlightened
Joined
Dec 16, 2016
Messages
219
Location
Cafner
Ok. It could be that your battery just has an 'under-security-threshold" voltage and thus, your charger refuses to charge it.
 

LED Monkey

Enlightened
Joined
Apr 25, 2016
Messages
281
Location
Massachusetts
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

Enlightened
Joined
Apr 25, 2016
Messages
281
Location
Massachusetts
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

Enlightened
Joined
Dec 16, 2016
Messages
219
Location
Cafner


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 ! )
 
Last edited:

LED Monkey

Enlightened
Joined
Apr 25, 2016
Messages
281
Location
Massachusetts
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

Flashlight Enthusiast
Joined
Feb 8, 2007
Messages
3,376
Location
WI
+

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
 
Last edited:

Lynx_Arc

Flashaholic
Joined
Oct 1, 2004
Messages
11,212
Location
Tulsa,OK
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

Enlightened
Joined
Apr 25, 2016
Messages
281
Location
Massachusetts
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

Flashlight Enthusiast
CPF Supporter
Joined
Apr 25, 2008
Messages
2,871
Location
Cleveland,Oh
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

Enlightened
Joined
Dec 16, 2016
Messages
219
Location
Cafner
...
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:
 
Last edited:

orbital

Flashlight Enthusiast
Joined
Feb 8, 2007
Messages
3,376
Location
WI
+

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

Enlightened
Joined
Apr 25, 2016
Messages
281
Location
Massachusetts
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
 
Top