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Version actuelle par : arsingenia

Texte:

A few things.
1. This is possible, if not exactly easy. It is also definitely cheaper, and you can produce a battery pack that's as good or better than the original if you make sure to purchase high quality cells.
2. This claim: "But what is worrisome is that despite doing so, I have been given to understand that there is a special electronic circuit in the battery pack which is intentionally programmed by Dell to block the PC's access to the battery cells (even if the cells are OK), after a specific number of hours of use or a specific number of recharge cycles, so even after changing the cells inside, the battery pack will remain dead, i.e. inaccessible" is not true.
What is true is that charging lithium cell is not like charging your old NiCd batteries or your car battery. If they aren't charged properly they can catch fire in a most spectacular fashion. Lithium batteries degrade relatively quickly, used or not. They are also sensitive to temperature. Right now, that's the price of high performance.
If you completely discharge your battery (any battery, for that matter), you can throw it away.
So you need a battery controller that will:
- keep the temperature within a safe range
- prevent overcharging
- prevent overdischarging - even as the battery performance declines with each charge cycle.
- accurately estimate the remaining operating time
The battery electronics "learn" the discharge curve of the cells in the battery. (How that discharge curve looks depends on the number of charge cycles, ambient temperature, and discharge rate, among other things.)
-To know how to do this "learning", the circuit in the battery is programmed at the factory using volatile memory. If you just yank the old cells out without providing operating voltage to the battery controller, the memory gets erased and your battery and laptop-specific programming is history (and the battery is now a doorstop, no matter how new and fabulous your replacement cells are).
+To know how to do this "learning", the circuit in the battery is programmed at the factory using volatile memory. If you just yank the old cells out without ensuring operating voltage to the battery controller, the memory gets erased and your battery and laptop-specific programming is history (and the battery is now a doorstop, no matter how new and fabulous your replacement cells are).
-That is the reason why these retrofits so often fail. It is a tricky thing to make sure that you are providing the spec voltage to the battery electronics while you swap out the old batteries for the new.
-
-This is why the quality of third-party battery packs varies enormously (the $45 pack youtbought was worth exactly what you paid for it, if not considerably less).
+That is the reason why these retrofits so often fail. The battery controller can't go without juice for very long. The memory will hold for a while, but not forever: stopping for a break in the middle of the job is a mistake.

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Contribution d'origine par : arsingenia

Texte:

A few things.

1. This is possible, if not exactly easy. It is also definitely cheaper, and you can produce a battery pack that's as good or better than the original if you make sure to purchase high quality cells.

2. This claim: "But what is worrisome is that despite doing so, I have been given to understand that there is a special electronic circuit in the battery pack which is intentionally programmed by Dell to block the PC's access to the battery cells (even if the cells are OK), after a specific number of hours of use or a specific number of recharge cycles, so even after changing the cells inside, the battery pack will remain dead, i.e. inaccessible" is not true.

What is true is that charging lithium cell is not like charging your old NiCd batteries or your car battery. If they aren't charged properly they can catch fire in a most spectacular fashion. Lithium batteries degrade relatively quickly, used or not. They are also sensitive to temperature. Right now, that's the price of high performance.

If you completely discharge your battery (any battery, for that matter), you can throw it away.

So you need a battery controller that will:

- keep the temperature within a safe range

- prevent overcharging

- prevent overdischarging - even as the battery performance declines with each charge cycle.

- accurately estimate the remaining operating time

The battery electronics "learn" the discharge curve of the cells in the battery. (How that discharge curve looks depends on the number of charge cycles, ambient temperature, and discharge rate, among other things.)

To know how to do this "learning", the circuit in the battery is programmed at the factory using volatile memory. If you just yank the old cells out without providing operating voltage to the battery controller, the memory gets erased and your battery and laptop-specific programming is history (and the battery is now a doorstop, no matter how new and fabulous your replacement cells are).

That is the reason why these retrofits so often fail. It is a tricky thing to make sure that you are providing the spec voltage to the battery electronics while you swap out the old batteries for the new.

This is why the quality of third-party battery packs varies enormously (the $45 pack youtbought was worth exactly what you paid for it, if not considerably less).

Statut:

open