New Battery After 2 Cycles Already Defect!
In previous repairs I wrote about successful fixing old laptop battery packs.
In this article I write about a new sort of battery pack that turns into useless brand new battery packs even after having been used for only 2 charge cycles. Which happens when you leave the battery pack for a longer time out of your laptop while no longer charged. And at the moment it loses its internal battery voltage below a certain level it won’t function anymore. And neither will be charged in your laptop afterwards anymore.
The battery pack I write about here is for my Compaq Presario C700 laptop. Bad packs still can be read with the BE2WORKS program and its special USB adapter like I wrote about in my previous article. Sadly these new type of battery packs can’t be reset to new packs with BE2WORKS. And sadly BE2WORKS can’t be used with most new batteries because they use new controller chips. Like the 38 pins SH79F329AX chip that BE2WORKS only reads but can’t reset.
Above photo shows my brand new battery that turned into scrap after only been used for 2 charging cycles. Although I kept it on a safe place practical fully charged like the instructions that came with my brand new pack said, it still became useless after it apparently had lost its internal battery charge without being used!
The 3 in series placed x 2 HT Great Power Li-ion batteries likely were of inferior quality because it is not normal that 6 batteries lost their energy after not been discharged other than by its internal controller. The controller, if we read the datasheet, is a special enhanced 8051 type of CPU. Following screen snapshot shows the information that BE2WORKS with the connected special SIL 2112 USB adapter still was able to read after my brand new pack became useless.
BE2WORKS in its present state is hopelessly useless. It won’t help in any way in fixing these new kinds of packs with controllers that BE2WORKS simply can’t fix/reset.
Previous photos showed my after 2 cycles already useless replacement 10.8V 5200mAh pack. Notice that my replacement battery had no safety temperature sensor attached. Which makes this product doubtful for another reason, and therefore I won’t buy another pack for my Compaq Presario C700 anymore. Also because my original battery suffered from exactly the same condition, not being able to use it only after it had lost its internal battery voltage.
Although BE2WORKS was able to reset that controller before I replaced the original old 18650 Li-ion cells it won’t be able to reset my new pack with the SH79F329AX chip. It only could reset my old original pack with a BQ 2084DBT controller chip. And most likely this new SH79F329AX controller is programmed with a special JTAG Flash programmer (which also the F for Flash in its name predicts).
This also means that the manufacturer of these replacement battery packs most likely has placed a special firmware program in these controllers. And no doubt the firmware after reaching a certain internal battery voltage level interrupts the battery from operating normally afterwards. Maybe by resetting its internal program state or by blowing a security fuse on its charging board. And after seeing the complexity of the SH79F329AX chip in the datasheet of this CPU it is unlikely that an easy repair or fix is possible to recover from being a taken down battery pack. And for safety reasons any cheap modification to regain the battery function is a bad idea. Also notice that on my new battery controller board besides not having any temperature sensor there is also no fuse installed. There only is a current measure resistance on board. Which means that all safety is software/firmware controlled.
Next JTAG picture came from the controller datasheet.
As I mentioned now both packs were scrap. I will still be able to use the 18650 separate cells in other projects but you have to agree that these kinds of battery packs are just bad products no consumer ever wants to buy!
Next brochure is the warning that came with my brand new pack with the internal HP6000-79 board and the SH79F329AX controller chip on it.
That told me to never fully discharge the battery! (Leaving 2% charge at minimum and at least 70% charged when not in use. Which I did but still it is dead now!) Next photos are taken from my original bad HSTNN-LB42 battery pack. Now also defect for most likely the same reason.
Following page about the SH79F329 controller from another controller datasheet shows how the chip is connected to max 5 li-ion cells. And also how the chip can be read using a USB connected PC (the way how BE2WORKS works with its special SIL 2112 adapter). In this same datasheet a special SMARTBATTERY FOR E-TOOL program is used to read and also write to the chip. Sadly these mostly in Chinese written datasheets leaves many questions open.
This special Smartbattery program to write and read the firmware likely will fill the gap that BE2WORKS shamelessly leaves open.
Conclusion: Be aware of these new kinds of laptop replacement battery packs that easily become completely useless. And normally can’t be fixed without the right tools!
After hardly been used and even after put aside fully charged like in the instructions was mentioned, packs become trash. And as result no 2 year warranty can solve these bad designed packs that use special firmware that Manufacturers use and obvious do not share with their battery pack buyers.
Firmware that surely won’t be able to measure the pack’s temperature when as in my brand new pack there is no NTC sensor attached!
Also be aware that most new laptops unlike my Compaq Presario C700 that works perfectly on the adapter only, newer laptops won’t work correctly without any battery pack inserted. Which is the case with laptops like my refurbished Lenovo 430S laptop that although it works on only the adapter,
doesn’t show any played video without showing artifacts while decompressing the video when the battery is not inserted.
Maybe these packs can be safely repaired by replacing old cells by new 18650 li-ion cells while
keeping the pack voltage high enough. But packs that destroy themselves while not even being used is a bad thing to say the least!
I hereby hope to warn anyone interested in fixing these newer replacement battery packs that they are a real problem. It makes resetting or fixing them quite impossible without the right tools.
Addendum! As could be seen on the first BE2WORKS screen copy (VCELL1) , the 2 lower li-ion cells (The black and yellow wires to the controller board. See next photo) were almost gone being discharged far below their minimum 3.7V voltage. They were just about 2.0V and almost unrepairable damaged! The 4 other cells were still fine!
After I had removed them from the pack and tried to recharge them on my OPUS BT-C3100 Battery charger they at first were very unstable and the current went up and down a couple of minutes at around a low 95 mA. And their voltage was just around about 0.18V at first. But after a while they regained their normal voltage and the current went up to a steady 500 mA. After a couple of hours both were charged to 2201 and 2218 mAh at an end voltage of 4.17V.
So to test the pack again I put both cells back and tested the battery in my Compaq Presario C700 laptop. I tried to start my laptop only on my battery but nothing happened. But after also the power adapter was connected and Windows 7 came up, it showed a fully charged battery pack. (Which explains why at first my charging blue led didn’t show). And after I removed the adapter my laptop worked again on only using the now assumably ‘repaired’ battery pack!
It is a fact that previously both bad 18650 battery cells were discharged badly by the controller board itself. And the manufacturer must have known about this problem all along why he warns about this in the brand new battery accompanied instructions.
And because normally any layman wouldn’t know how to open and recharge those 2 cells he is warned. Sadly after this 2 cell repair the battery pack now never really gets charged anymore although my laptop shows a charging battery in its window.
So my final conclusion here is that the special SH79F329AX processor somehow still prevents the pack from a normal charging operation. And the controller board is also the reason why two of the six 18650 Li-ion cells were severely damaged to a dangerous level!
By-the-way: As shown on one of the previous photos, the battery connector has 6 ‘pin’ connections. P+ D C NC T and P-. Never attach the P+ pole (only if the battery needs some small charge if BE2WORKS can’t see it)!
I used a RF 20-6 connector (A set of battery test connectors I bought online) with the SIL 2112 adapter SCL wire connected to pin 4/C, wire SDA goes to pin 5/D, and I connected battery pin T to ground (pins 1 and 2 bridged). Ground of the SIL 2112 BE2WORKS adapter of course also goes to pin 1/P-.
Albert van Bemmelen, Weert, The Netherlands.
Please give a support by clicking on the social buttons below. Your feedback on the post is welcome. Please leave it in the comments.
P.S- If you enjoyed reading this, click here to subscribe to my blog (free subscription). That way, you’ll never miss a post. You can also forward this website link to your friends and colleagues-thanks!
Note: You can read his previous repair article in the below link: