DIY Fixing a Laptop Battery

Hi Friends ,

 DIY is always fun and awesome, and so welcome to another word of tech byte...

This note is a collective scratchpad of troubleshoot methods and fixes i came across recently for fixing my laptop battery that went bad.

Battery Model   : HP HS04 battery pack (4 cell , lithium ion, 14.6V , 2670 mAh, 41 Wh)
Laptop  Model  : HP 15-ac635tu   (equivalent to HP G4 250 Notebook)

The Symptoms Laptop Showed
1. Laptop charger goes on and off intermittently after charging up to more than 60% . The charger port LED goes between charging and not-charging frequently.

2. Once laptop is running from battery, charge percentage drops faster than normal, and once it reaches 23% , laptop shuts off immediately. On power in on again the charge percentage will be less than 15% and wont complete bootup to desktop. Faints instantly.

Troubleshooting

1. Borrowed a laptop charger from my friend and tried 2 or 3 charge cycles. But still the issue     persisted.
    This confirmed that my charger does not have any role in intermittent charging.
2. Ran the battery checks in Components Test in System Diagnostics in  BIOS screen.
    To my luck it had listed each cell voltage like below ,  and i found the culprit.











As you can see the cell number 4 has gone to a lower voltage comapared to other  3 cells.
So this little guy (#4)  has gone pretty weak and is affecting the collective 14.6V of the battery pack adversly. He is not consistent anymore and i found that it discharges first to lower voltages like 2.8V after a complete charging cycle. Other cells still maintain around 3.2V at the same time.  This makes the laptop shut off immediately.

Phew .... time for shopping new battery pack...
And www.hpshopping.in says Rs 3171rs for new HS04 genuine battery pack. 😕

Opening up the Battery Pack - The crude way
 Manufactures make the battery packs in such a way that they are not intended to be serviced.
The pack itself is two plastic pieces , pressed against each other. The  hooks/locks in between these pieces are arranged at inside , in a way that once we try to pry open , they may easily broke. Same happened for me too.  With almost like 15 minutes of struggle and numerous attempts i could understand that there is no way i can easily open it. Increased the force and few locks got popped/broke.. At last  i opened it and it looked like as below



The battery pack contained four , 18650 type cylindrical cells from LG Chem with model number LGABC41865.

18650 Type Batteries are a very popular category of lithium ion batteries in cylindrical shape. They even power Tesla Cars. They are very know for the flat high current delivery across more  range of volatge during discharging.
Major characteristics of these batteries are based on their battery chemistry, terminal voltage, current capacity

Here we have LGABC41865. Its specs could be found at https://secondlifestorage.com/t-LG-LGABC41865-Cell-Specifications


After a few hours of search in flipkart, amazon and other less known website i found out that a good amount of copycats of 18650 type are traded and is available in plenty.

A seller was in amazon.in who selling  original lithium battery with a high price. But the model was LGABC21865.

I decided to buy one as this has very similar specs to LGABC41865. Price was 547/- including shipping.

Note :- It is always recommended not to mix different type of Li batteries even though they are technically same. But i was running on a tight budget so decided to go forward with this model.


In 6 days, new battery came (orange in color)  , soldered it in place of old cell #4 as below..




Replaced battery plastic covers.. Sure the edges look ugly due to forcefull prying. And powered the laptop . The results are impressive .

Gets almost 2 hours backup now , which was less than half hour before. The charge cycle count got reseted .

The HP battery checker software is also happy about the charge capacity of new arrangement.  The new cell at #4 is pretty solid and gives the highest terminal voltage now.. Also the battery doesnt seem to warm or heat up. So i guess the DIY upgrade is a success..




Recommendation
Do the manual battery calibration suggested by HP in below page for proper Charge capacity reporting
https://support.hp.com/in-en/document/c04700771



Comment below if guys have any specific doubts or helps needed in your journey of upgradation. Will help with my knowledge about this more..


Comments

Yagnik said…
I have same battery, its not charging or discharging. I have checked voltages, all cells have good voltages. How did you reset cycle counter?
Antony said…
Hi Yagnik, Since i opened and kept the battery circuit disconnected from cells for quite a few time, i think the counter got cleared.. I did nothing specific to clear the counters in ssoftware..
Saif said…
Hi, can you please tell me the current status? I want to do the same but little bit worried if it is not long time or may get damaged...
Antony said…
It's running fine ... @Saif
Recently I changed one more cell out of four... I would suggest to buy good quality cells.. it's hard to find.. lots of copycats
Prakash said…
I am also having same battery isuue can you suggest me the best cell please
Antony said…
Amazon has a seller MK enterprises. They do sell quality cells
TechXp-2007 said…
Can you share the link of the battery you bought?

Also can you tell what terminal voltage you get after full charge. Im asking this because i have recharged all the other 3 cells by external charger and they have voltage about 3.8- 4.2 so now combined voltage is above 15.3volts and max terminal voltage that shows in battery check is 14600mv or 14.6v
Antony said…
Yes .. 18650 will have upto 4.2v on full charge...it will come down and stay in 3.7v for long time . That's why the rating is said so..

https://www.amazon.in/dp/B074LZ5QW8/ref=cm_sw_r_cp_apap_4MyBbZCGmd7bA
TechXp-2007 said…
Thanks.
1) But the link is not working. Can you please resend the link?

2) Secondly inside battery check how much terminal voltage you are getting on full charge. Bcos battery check shows me 15-16volts.

3) My 4cell the one at the negative side is bad and that's only 3.7 on full charge and battery check shows full capacity to 1600mah. May be becos of this cell complete mah is down and pcb controller ia not running using it to power laptop.

So right now i dont have any new cell to buy from Amazon but have old laptop battery that was new but laptop died, it has 2000mah battery. I was wondering to add it in place of 4th cell may 2 in parallel that makes it 4000mah to see if the laptop accepts it as they need minimum 80% of the rated capacity to turn on the circuit.

So before doing that i need to make sure that the total terminal voltage on full charge can be higher, that's why i asked you how much you get when your battery is full charged.

Thanks.


Antony said…
1. Look for a seller MA Enterprises in amazon.in ( the battery is not listed now , may be out of stock . [9881235730 seller whatsapp]

2. its normal to give 15-16V on full charge , but the catch is whether it will subscide these levels fast.. that means cells may be weak..

3. One cell being weak means , the whole pack will fail fast to lower 11v and adapter will cut of powering the laptop.

Li-ion cells are nowhere like old any normal ni-cd batteries where you can parallel and do stuff..
Dont mix Li battery types and charge.. this may work , but will ruin other batteries. Chances of heatup and burn are high.
The li-ion charger is not just a simple voltage provider.. It does so many things to charge the cell safely. Since laptop battery pack is multiple cells , charger has more functions like cell balancing...

Find a equivalent cell of your battery and replace.. or invest in a genuine new pack.


Unknown said…
Hi,
My battery was having the same behavior.
I have also tried the same thing with the same(HS04) battery.
I dont know what went wrong but battery is not working, all the cells are giving 3.8v and in combination it is giving 15.6v. But when i am checking the voltage from battery charging circuit it is showing 0v.
Now i have replaced everything as it is(used the old cells only) still the same result. Now My laptop is not turning on without charging cable.
Previously atleast battery was giving a back up of 1 hour.
Preet said…
I am having the same HS04 battery with LGABC41865 model. And now i am looking for the new cell. Can anyone please provide the info from where i can bought same configuration cell.
Thanks.

Popular posts from this blog

Bidirectional 3.3v 5v Level Shifter

USB-UART console using old nokia DKU-5 datacable. (3.3v TTL)