Rebuilding Battery Pack-L09S6Y02 Of LENOVO Laptop Model V570

This battery pack belonged to the laptop given to me by my son. When it started showing low battery warnings and stopped switching on, I knew that time had come for me to take action. I took out the battery pack from behind sliding out the two stoppers. Then applied petrol on the sides where the top and bottom covers were glued together.

Then pried the cover open by working the way from one end to the other. Let us have a look at the inside and how the cells are interconnected:

Six cells with two in parallel are connected together in series. So each set will give 3.7V with higher amperes. There were four tappings from the cells that go to the control board; LP1, LP3, LP4 & LP5. Unfortunately I forgot to click the board and its IC numbers! LP5 is the negative point, LP4 is from the next set of two cells, LP3 is from the next set and LP1 is the positive point. I separated the cells and measured every one of them and found that except two cells, rest was ok. I kept all the cells for charging separately in single cell chargers and checked again after the charging was complete. Then all the cells showed around 3.9V.

Then checked them with a torch bulb load. Two cells drained quickly showing that they were the culprits. Anyhow, we need to replace all the six cells together at a time and combining them with other brands (Incidentally, there were no markings on the cells!) is not at all advisable. The unchanged cells would soon fail one after the other sooner or later. I fetched 2600mA Foxpro cells which were definitely better rated. I drew a crude sketch on the table with sketch pen to know how the cells were connected with the numbers of the connectors:

What you see in the second picture above is the new cells and spot welding materials that I bought for handling such jobs. I have already covered about the spot welding machine in my previous articles and therefore I am skipping it here.

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Since the two cells are separated by a partition in the box, we need to take care that the fresh spot welding of tin sheet is done with the gap for it. First I removed all the four connectors from the board. Kept two cells in its compartment with the partition occupying the middle. Then spot welded LP5 to the negative sides of two cells. Then inverted the cells and spot welded the positive sides. Kept next set of two cells together bound by rubber bands, in parallel with the first two and welded the other ends to the negative points. Then bent it and placed it in the compartment. Thus four cells were in place with LP4. Welded the positive sides of the two cells and repeated the same for the next set of two cells and placed it in the compartment, completing the LP3 connection. Lifted the positive ends of the third pair of cells and welded them to complete the LP1 connection. After checking and confirming that there were no man made mistakes, soldered the four connectors back to the control board. Pressed down the cells and control board very well and put the top cover. Aligned the connector properly and fit it tightly in its slot. I did not apply any glue in the covers to bond it together, as I might have to open it in case it was found not suitable and rejected by the Laptop battery manager, like what our body does when alien things are implanted! (LOL) Sometimes current mismatch would create such problems. After fitting the battery in the laptop, when I switched on, the battery indicating icon showed charging four times and then displayed “0% plugged in, not charging.” I knew that the Battery Manager is objecting to accepting the new set of batteries. I combed the web for solutions and one solution was to select device manager-batteries￾Microsoft ACPI-Compliant Control Method Battery, then try updating the driver, which I did.

But this did not solve the problem. Next step suggested was to uninstall the ACPI-Compliant Control and shut down, wait for a few seconds and start the laptop again. Even after doing that the error was indicating same. Then when I happened to look at the battery indicator while typing this article, it showed full! I was pleasantly surprised and did not know what made it ok as I was concentrating on typing! Perhaps the Manager got worried that ‘his’ adamant nature was getting exposed to international level, where experts are going to read it and therefore decided to accept the second ‘employee!’ (LOL)

Anyhow, now I can say that mission got accomplished with inflated satisfaction getting added to the collection. Here is the proof for my claim:

This article was prepared for you by Parasuraman Subramanian from India. He is 76 years old and has more than 30 years’ experience in handling antique equipment like Valve Radio, Amps, Reel Tape Recorders and currently studying latest tech-classes conducted by Kerala State Electronics Technicians’ Association. He has done graduation in BBA degree, private diploma in Radio Engineering and retired as MD of a USA company. Presently working as Consultant to Hospital and other institutions.

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You may check on his previous article on Saved Yet Another Wasp Infested 2-IN-1 Of NATIONAL Make, Model RX-CW54F

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