What's next?

Bought this:

And get this:

I can't help you, but...

If you bought a power bank...

And get this?

May be I can help you to fix it, remove the sand bag, put in what it deserve.

Li-ion battery pack prototype

This is an order from one of my customer.

This battery pack have built in over charge, over discharge and short circuit protection, 12.6V 1.5A charger provided. It is a 10.8V 27Whr battery pack, operated from 12.6V (when fully charged) down to 9V (when fully discharge), can be used for most 12V powered device that use less than 12W. It take aproximately 2-3 hours to fully charge the battery.

8.4V Linear Charger

This is an custom-built order from one of my customer a few days back, his UMPC battery is unable to be charged by his notebook. After he have comfirmed that is the UMPC problem, not battery problem, he send it to me to make a custom charger for him. A picture is worth a thousand words.

Picture below: charging a 7.2V li-ion battery pack, the LED will go off when the battery is removed or the charging current is less than 70mA.

Technical Spec:
Type: Linear Series Regulation, Quick Charge Catagory
Maximum Charge Current: 1.1A(+/-5%)
Maximum Charge Voltage: 8.4V(+/-1%)
Input Voltage: 10V-12V
Input Current: 1A
Charging Speed: Reach 70% in 2 hours, 100% in 5 hours (for 2600mAH 7.2V pack)
Fully Charged Indicator: LED, lit up when charging

*No trickle charge mode built in, no suitable for battery that have been drained down to 0%
*This is not a recomended way to charge your battery, although there are built in protection in the pack.
*Not suitable for battery with capacity less than 1000mAH, as the charge pump in rate may larger than the chemical can accept, can result in battery overheat.

Battery Repair

Sekarang, RM60 untuk membaiki bateri notebook anda yang telah ditukar sel baru! Jika anda telah tukar cel di dalam, tetapi bateri itu tidak berfungsi setelah digantikan sel dalamnya!

Jika sebelum anda tukar sel dalamnya, ia berfungsi, maka adanya jalan untuk mambaikinya. Kami membaiki kebanyakan bateri yang tidak dapat dibaiki oleh yang lain! Jadi, kenapa tidak cuba guna perhikmatan ini untuk membaiki bateri anda?

Untuk pertanyaan tentang suatu model bateri tertentu boleh dibaiki atau tidak, sila hubungi kami dengan emel atau pangilan talifon.








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您刚自己换了电芯的笔记本电池不工作？现对外提供笔记本电池解锁服务！只须RM60。

只要你在换电芯之前，电池是工作的，都有很大的机会可以再次修复！

就算你在换电芯之前，电池是不工作的，只要不工作的主要原因是电芯损坏（内部PTC切断、短路等），没有次要原因，同样有很大的机会可以再次修复！

我们拥有足够的工具检查出问题所在，只有少数的特殊电池没有办法处理。欢迎电邮/来电查询单一型号可否修复。

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Now, RM60 to repair your re-celled battery! If you have recell(reload a new group of new/used cell) your battery, but it don't work (it actually working before you send to repair) or not work properly, just send it to Alternative Battery. RM60 to make it work! Performance will depend on the cell you have change.

Besides, now we have width range of cell to select, just let us know you budget. Tell us your battery model we will let you know if it can be fixed. Just to ensure you get a working battery.

Alternative Battery Enterprise have own engineered tools needed to check and configured the battery properly. Many battery that can be repaired by us not even be supported by the hottest custom battery repair tools that widely available in the global market.

Our tools and equipment can check most of the smart battery in the market, included SMB, IIC, IBA, ONEWIRE interface. Rate of a battery being success to be repaired is more likely>90%. Therefore, all the customers get their battery with full satisfaction!

M520GBAT

Just for you information, this battery can be realt, no problem.

Sometime the fuse blow, replace the thermal fuse with working one. This is sometime very troublesome, if not done properly, the fuse will blow again! Especially if one not solder it fast, the heat from soldering iron can melt the conductor inside the fuse also, because it is a thermal fuse.

The primary purpose of this thermal fuse is to prevent battery keep operating if the MOSFET(the black chip below the fuse) is overheat. MOSFET can overheat if the main protection chip fail to detect an over current condition. MOSFET can also overheat if over current occur but the MOSFET itself shorted(not working).

Those fuse can also be intentianally blown by the controller circuit if the battery controller have a sense of cells over-heating or over-charged, that is why it have three leg, one is for control, connect it to ground will blow the fuse. But if the overheating occur due to short circuit inside the cells itself, cut off the supply of current to notebook won't prevent it from continously treat by overheat or even catch fire when reach a certain temperature treshhold.

Replace the cell with new one.

Connect the new cells to the circuit board and apply some silicone glue to the temperature sensor. The reason using silicone glue is it can withstand up to 400 degree Celsius. If using normal glue, it will melt when cell overheating occurring.

Great workmanship cause housing are open nicely.

This is first time I see QFN chip pakaging for the bq chip, normally is TSSOP.


TSSOP is long IC. QFN is smaller in size by around 20%.

Problem of one of my customer

One of my customer report that my battery is under spec as his original battery can give him 2:30hr standby time while my battery only give him approx 2 hours, At first I think that it was my cells problem since my cells is rated at higher spec than his, suppose to do better than his original.


Then I try to charge and discharge my cells, at first it work fine as state in their example curve, but at the end of discharge, it drop down faster than it should and record a >2260mAH for a cell discharge at 2A take approximately 80 minutes from 4.2V to 3.0V, Samsung suggest discharge to 2.75V. This mean if combining 2 pieces it still have at least 4500mAH suppose to work better than his original battery. Note that Samsung don't sell 2300mAH battery, if I discharge it to 2.75V there suppose have 23++mAH, so they label it 2400mAH, will be 4800mAH on most notebook battery pack.

There is however it isn't, I have come out with 2 assumption:
1. Sony rated 4400mAH work better than 4400mAH.
2. Samsung built in PTC (Positive Temperature Coefficient) thermistor have higher resistance than Sony, thus result in battery pack have higher voltage drop across PTC, this assumption was made base on I trust my supplier cells since they always do so. And the cells have thicker isolator among electrode, result in higher cells resistance than Sony but it is safer to practicing this.

Higher voltage drop across PTC result in faster false triggering of Near End (~7%) or end of discharge (0%) voltage reach (So battery board fell that cells is empty even there may be still around 10-20%) .

At different current flow, higher current will have more voltage drop across PTC, resulting in EDV shift to lower to allow correct power meter, EDV various base on the preset value defined by the specified setting in a particular pack.

Newest battery IC with built in impedance tracker will track the impedance of cells for different battery, reduce the need for technical people to set the value for fine tune according to different type of chemical. Example is bq20Z70/Z80/Z90 family, but it is still expansive so rarely a factory want it, only big company adapt it to reduce the complexity and time for implementation/production of a battery for a system.

So this few weeks I shall study how the manufacturer set EDV for Samsung Cells compare to Sony cells. I will do some experiments to prove this since hard to get all the spec for those industry cells.

Sorry for my incompatible for this issue since this is first time I use Samsung cells, along the years I seen minimum case of leakage ever occur on Samsung cells and Sony cells, but Sony have some no so good history record so I decided to go for Samsung which seen safer. No to look down on Sony cells, it is powerful and they perhaps have making their lesson over the years.

Learn a lesson here, sorry my customer. I believe this will not occur on notebook battery that originally using Samsung cells, which I will contact another customer who originally cell is Samsung to verify this.

P/S：Sony EDV0 is 3050mV, will track back Samsung from my old file. EDV1 and EDV2 is checking now hope will get conclusion soon. There are more than two version of bq2084, most commonly use is v133 and v143 which have different dataflash format. I am really sorry as I am not the best technical. I suggest those who want to do refill battery, learn properly, some battery is easy to refill but some make people headache.

Update(27June): Base on EDV Discharge Rate and Temperature Compensation Programming in manufacturer's manual, I found that EDV is calculate base on

EDV0,1,2 = n (EMF * FBL – |ILOAD| * R0 * FTZ)

Update(2July): Finally I get back the battery and I check what happening, strange enough, I didn't found any problem occur on the battery, it register a capacity of 4667mAH after a few cycle use, although it didn't reach 4800mAH, but at least it won't let you down. As I know, all brands of cells is sell in this way, they sell the cells base on closer capacity, example 2330 will be rate as 2400mAH but not 2200mAH. 2200mAH usually it will only have 2100+mAH nominal capacity. Even I discharge the battery, it will still do more that 4700mAH in 3Ampere discharge current. Now I am start to think, Sony label some very high capacity cells example 5200+mAH cells and sale it at spec 4400mAH to the manufacturer, to show that their battery is strong or because the market demand it but in their stock is all high capacity, so they remark it to lower capacity.

In fact, mAH is just a reference, many people don't know that high power cells that can continuously supply more current (a few time more) than normal cells, if discharged in low current, can supply more WHr even it discharged at same amount of mAH, that is why some people prefer using unit WHr than mAH. But high power cells is more dangerous in my point of view, some high power cells can supply more than 10A continuously, if short circuit occur inside the cells (dielectric is too thin, more tend to be punctured by crystal built up inside the cells), can result in explosion.

This is similar to processor manufacturer produce many low frequency processor because market demand on it is higher, it doesn't mean that the processor is slow. So it can be over clock to higher speed. Example some 1.6GHz can over clock to 2.0GHz without rising it voltage. When they speak about global huge market, they want cash flow rather that store the stock since electronic products going to become obsolete very fast.

All trademark is belong to their owner, this technical document is post for learning purpose only.

What we do?

We replace the worn and teared battery cells of your notebook battery on a very practical level.

Professionally treat to most notebook battery pack, promises to deliver:
-nice or superior work.
-Spot Welding, effective connection between cells.
-Brought to you by altbattery.com!

With the high capacity 4000mAH battery. We guaranteed that the battery send back to our customers work more than or close to 100% performance (provided that your original capacity is 2700mAH, 3600mAH, 3900mAH, 4000mAH or 4400mAH) compare with original or else 100% money back guaranty within one week from the date of purchase. In fact, most of it reach more than 100% compare with original.

More important is, your battery can be tested the way it should be by us. Over one year, we have developed a various way of testing battery with different brand. To test a battery properly, it will need some intel's System Management Bus comply reader and writer, to get current condition of the battery and some extra information, for example, number of cycle of your battery, manufactured date, reporting battery running parameter(voltage, temperature, etc), wear level and etc.