Need help with laptop battery repair

Question

Batteries

We have a battery from Acer 14.8V 4000mAh
At the opening, 8 cans were found.
According to my calculation, each bank is 500 mAh.

There are approximately the same cans on dilekstreme, but with a capacity of 2700 mAh.

I would like to try to replace the old ones with Chinese ones without changing the connection scheme.

If you look closely at the photo, you can see that there are 4 plugs for cans, i.e. as an option, you can install 12 cans in the battery.

Those. it turns out 12 * 2700mAh \u003d 32400mAh is about 8 times more than the volume and following this logic, if the battery previously held 2 hours of battery life, then when switching to a new one, it will hold 16 hours.

But there is a difficulty how to make a connection diagram in this case and how the controller will react to all this.

The controller, like the entire battery, is not particularly a pity, it is more important that when the battery gets into the laptop, the laptop does not burn out.

Answer 1

Your laptop has a charger. If the charging current is equal to 1/10 of the battery capacity, then, theoretically, the charging time will be 10 hours, but the real charging time at this current will be 16 hours. Some chargers may stop charging, either by time or temperature or a combination of other factors. Therefore, installing instead of 2700mAh cans at 32400mAh, you will not get what you want, because. you do not change the charger. Charging time can be roughly calculated using the formula: Charge time (h) = 1.4 x Capacity (mAh) / Charging current (mA). If you install the banks correctly, observing the voltage, then the charger will most likely not burn out, but the charge time will be very long, and this can already burn it. I adviseread literature about lithium-ion batteries, their capacity, calculation of charge and discharge times (just copy this into the Google or Yandex search bar and you will find a lot of information to read)

Answer 2

and if you take 12 cans with dx to 2700mAh, then by connecting three in parallel, and then in series, you will get a capacity of 2700 * 3 = 8100mA. Really, it should be about 6-7Ah.

Answer 3

In your case, each bank is 2000 mAh, so the charge time will not increase much. And given that these are batteries with dx, then with a high degree of probability it will also decently decrease :)

Answer 4

Does the capacity depend on how the cans are connected? :) The output voltage, not the capacitance, depends on the geometry. Strictly speaking, you need to multiply the ampere-hours by the voltage to get the absolute value of the energy capacity.

Answer 5

Well, yes. We connect the banks in parallel - the capacitance increases, in series - the voltage.

Answer 6

The capacity is calculated by the number of circuits, since the circuit is discharged all at once. Capacity is written = cell capacity * number of circuits. In the picture, the most common cells are 18650. 3.7 volts, but mah 2700 cannot be exactly. They are according to the standard 2600. Moreover, the sellers in the left places lie shamelessly taking advantage of the fact that few people can check. You can solder it on the forehead if you put a larger cell capacity or make more circuits. Check the battery voltage. If 7-8 volts, then add it calmly. If about 15, then nothing will be added. For there are two chains of 4 cells.
Putting cells smaller than the original is fraught. They can catch fire from overcharge (I don’t know how it’s correct in Russian. Reloading type). Or you will have to correct the brains of the battery. Doable, but crap. It will be easier to order a new battery from China.