Battery Management System in the telephone battery

[martin007]

Hello.

In this forum we has talked long and hot of BMS.
Today I have found out that all las baterias de litio de los mobile phones have an integrated BMS...

[Burgerman]

A mobile phone has a single cell battery. Nominal 3.6 or 3.7V. The only management it has is that the phone allows you to discharge it down to 0% and probably 2.5V and this is bad for it.
And it charges it at the max allowable 4.200V or even higher, to maximise the lifespan of the battery in use. This is also bad for it.

There are one or two smartphones in existance that have huge 6Ah or 6000mAh batteries. With a sensible battery life. But they are not fasionably thin...

Theres no conventional BMS in the way that you are thinking.

[martin007]

[Burgerman]

All it does is chop off power at a high and a low voltage. For safety. The phones inbuilt software will never reach those extremes. So it there basically as a safety ornament... Many cells are available as "protected" versions. Usually the round ones.

[martin007]

It is a very basic BMS...

[Burgerman]

So basic it does nothing. It may even be a fuse.

[Burgerman]

In the same way you can buy many such small cells of lots of different sizes in the "protected" versions.
Such as the commonly used 18650 sized cells. https://www.ecoluxshopdirect.co.uk/by-s ... -protected

Or you can buy unprotected 18650 cells. These can be discharged to whatever voltage you want. And charged to whatever voltage you or your BMS chooses.

The idea being that the end user or consumer buys protected loose cells in the same way that you buy NMH AAs and similar for torches clocks etc. And then they are safe for use by dummies.

And the unprotected pure cells are for use with packs with cell taps, or by manufacturers, or with a BMS in say a laptop. Or with the PL8... hobby use.

The protected cells cant be charged in a pack in series. Because as soon as the first cell is "full" at 4.2V the protection opens up. So no current flows through any of the other cells. They are intended to be charged in a seperate charger like these: https://i5.walmartimages.com/asr/390f59 ... 6ac9ae.png or similar.

Or inside a phone, or whatever.

[martin007]

In the same way you can buy many such small cells of lots of different sizes in the "protected" versions.
Such as the commonly used 18650 sized cells. https://www.ecoluxshopdirect.co.uk/by-s ... -protected

Or you can buy unprotected 18650 cells. These can be discharged to whatever voltage you want. And charged to whatever voltage you or your BMS chooses.

The idea being that the end user or consumer buys protected loose cells in the same way that you buy NMH AAs and similar for torches clocks etc. And then they are safe for use by dummies.

And the unprotected pure cells are for use with packs with cell taps, or by manufacturers, or with a BMS in say a laptop. Or with the PL8... hobby use.

The protected cells cant be charged in a pack in series. Because as soon as the first cell is "full" at 4.2V the protection opens up. So no current flows through any of the other cells. They are intended to be charged in a seperate charger like these: https://i5.walmartimages.com/asr/390f59 ... 6ac9ae.png or similar.

Or inside a phone, or whatever.

I understand you.