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Electronics => Beginners => Topic started by: DW1961 on September 25, 2022, 02:11:30 am

Title: Lithium Batteries Removal and Project
Post by: DW1961 on September 25, 2022, 02:11:30 am
I have a couple of higher end enthusiast mechanical keyboards that were replaced by the vendor. They were defective right out of the box, so the battery in them is brand new, A couple are 2900mAh and so forth.

Instead of just tossing out the entire board, I'd like to save the batteries for other projects, and actually to fit two into one keyboard enclosure.

My question is How do I know when the battery is fully charged once it is disconnected from the keyboard electronics?

Title: Re: Lithium Batteries Removal and Project
Post by: ledtester on September 25, 2022, 02:34:24 am
What do the batteries look like? Post a photo!

Quote
My question is How do I know when the battery is fully charged once it is disconnected from the keyboard electronics?

For a single lithium-ion cell the magic number is around 4 volts. Dave did a video on what charging a single cell entails:

EEVblog #919 - How To Charge Li-Ion/LiPo Batteries With A Power Supply
https://youtu.be/jNmlxBXEqW0


Quote
... and actually to fit two into one keyboard enclosure.

Are you planning to use them in parallel or series?
Title: Re: Lithium Batteries Removal and Project
Post by: DW1961 on September 25, 2022, 07:24:14 pm
This is the only image I have of the battery in one board. The other is similar, but I'll have to open them up and extract them in order to see if they have any ID on them. It's teh flat black thing in the middle of the bottom of the board.It connects to the board with a small JST connector and two wires.

[attachimg=1]
Title: Re: Lithium Batteries Removal and Project
Post by: ledtester on September 25, 2022, 07:42:44 pm
When you open it up see if it has any protection circuitry like in this pic:

[attachimg=1]
Title: Re: Lithium Batteries Removal and Project
Post by: DW1961 on September 26, 2022, 01:02:20 am
OK I will. Thanks.
Title: Re: Lithium Batteries Removal and Project
Post by: DW1961 on October 15, 2022, 10:51:12 pm
When you open it up see if it has any protection circuitry like in this pic:

(Attachment Link)

I just got around to removing this battery. This is what it looks like:
[attachimg=1]
Title: Re: Lithium Batteries Removal and Project
Post by: sleemanj on October 16, 2022, 12:51:35 am
Standard protection circuit.  DW01 protection IC and 8205A dual mosfet pair, or work-alikes.
Title: Re: Lithium Batteries Removal and Project
Post by: DW1961 on October 16, 2022, 01:13:33 am
Standard protection circuit.  DW01 protection IC and 8205A dual mosfet pair, or work-alikes.

So that means it has over charge protection? Can I run two of those in Parallel and leave both protection circuits?
 
Title: Re: Lithium Batteries Removal and Project
Post by: sleemanj on October 16, 2022, 08:45:37 pm
Yes
Title: Re: Lithium Batteries Removal and Project
Post by: TheNewLab on October 17, 2022, 02:02:46 am
If it is a dead battery, I have a particle meter with a unique packaged Lith-ion battery. Could not find a replacement anywhere. Cracked upon the plastic case, de-soldered the Lith-ion batt packet, and soldered on a new battery to the little control circuit-PCB. Was a bi..h to do it so tiny, but it worked
Title: Re: Lithium Batteries Removal and Project
Post by: DW1961 on October 17, 2022, 04:46:39 pm
If it is a dead battery, I have a particle meter with a unique packaged Lith-ion battery. Could not find a replacement anywhere. Cracked upon the plastic case, de-soldered the Lith-ion batt packet, and soldered on a new battery to the little control circuit-PCB. Was a bi..h to do it so tiny, but it worked

That's a good idea. The battery is brand new. It was a bad 60% mechanical keyboard, and the vendor didn't have me send it back. That particular board is NOT getting the upgrade. It's too hard to break down the case w/o breaking the mode switch.

My other board is an 87 key and it's only a 2000mA battery. I also got a replacement for that one (dead switch socket) w/o having to return the defective board. I have not taken that one  apart, but it's easy with no small and delicate parts. I just have to get around to tearing it down and seeing if it is large enough in the pan to accept two of the original 2000mA batteries. If it is, then I have to decide if I want to buy a larger one (around 15-20 dollars) or run both original 2000mA batteries in parallel. But I gotta say, I can get a 3.7V 5000mAh Battery for 15 bucks. Still, if both bats fit, I'll solder them up.