The mentioning of limited service life on lithium-ion has caused concern in the battery industry

The mentioning of limited service life on lithium-ion has caused concern in the battery industry and I will need to add some clarifications. Let me explain:
If someone asks how long we humans live, we would soon find out that the longevity varies according to life style and living conditions that exist in different countries. Similar conditions exist with the Dell Studio 1735 Battery Original 56WH batteries, lithium-ion in particular. Since BatteryUniversity bases its information on the feedback from users as opposed to scientific information derived from a research lab, longevity results may differ from manufacturer' specifications. Let's briefly look at the various living conditions of the lithium-ion battery.

If possible, store the
Dell RM791 Battery Original 56WH in a cool place at about a 40% state-of-charge. Some reserve charge is needed to keep the battery and its protection circuit operational during prolonged storage. Avoid keeping the battery at full charge and high temperature. This is the case when placing a cell phone or spare battery in a hot car. Running a laptop computer on the mains has a similar temperature problem. While the battery is kept fully charged, the inside temperature during operation rises to 45°C (113°F).

A large number of lithium-ion batteries for cell phones are being discarded under the warranty return policy. Some failed
Dell KM973 Battery Original 56WH are sent to service centers or the manufacturer, where they are refurbished. Studies show that 80%-90% of the returned batteries can be repaired and returned to service.

All personal computers (and some other electronic devices) contain a battery for memory back up. This battery is commonly a small non-rechargeable lithium cell, which provides a small current when the device is turned off. The PC uses the battery to retain certain information when the power is off. These are the BIOS settings, current date and time, as well as resource assignment for Plug and Play systems. Storage does shorten the service life of the backup battery to a few years. Some say 1-2 years. By keeping the computer connected to the main, albeit turned off, a battery on the PC motherboards should be good for 5-7 years. A PC should give the advanced warning when battery gets low. A dead back-up battery will wipe out the volatile memory and erase certain settings. After

Toshiba Satellite M50 Series battery is replaced, the PC should again be operational.

Removing the battery from the laptop when running on fixed power protects the battery from heat. With the concern of the battery overheating and causing fire, a spokesperson for the U.S. Consumer Product Safety Commission advises to eject the battery of affected laptops and to run the machines on a power cord. It should be noted that on a power outage, unsaved works will be lost.
The question is often asked, should the laptop be disconnected from the main when not in use? Under normal circumstances, it should not matter with lithium-ion. Once the battery is fully charged, no further charge is applied. However, there is always the concern is malfunction of the AC adapter, the laptop or the battery.

Not only is it better to charge lithium-ion battery at a slower charge rate, high discharge rates also contribute the extra wear and tear. Figure 3 shows the cycle life as a function of charge and discharge rates. Observe the good laboratory performance if the battery is charged and discharged at 1C. (A 0.5C charge and discharge would further improve this rating.)

Permanent capacity loss of lithium-ion as a function of temperature and charge level.
High charge levels and elevated temperatures hasten permanent capacity loss. Improvements in chemistry have increased the storage performance of lithium-ion batteries.

The voltage level to which the cells are charged also plays an important role to longevity. For safety reasons, most lithium-ion cannot exceed 4.20 volts per cell. While a higher voltage boosts capacity, the disadvantage is lower cycle life. Figure 2 shows the cycle life as a function of charge voltage
There are no remedies to restore lithium-ion once worn out. A momentary improvement in performance is noticeable when heating up the Dell F287H G069H Battery Original . This lowers the internal resistance momentarily but the condition reverts back to its former state when the temperature drops. Cold temperature will increase the internal resistance.

The worst condition is keeping a fully charged battery at elevated temperatures, which is the case with running laptop batteries. If used on main power, the battery inside a laptop will only last for 12-18 months. I must hasten to explain that the pack does not die suddenly but begins with reduced run-times.

Longevity of high-power lithium-ion Generally speaking, batteries live longer if treated in a gentle manner. High charge voltages, excessive charge rate and extreme load conditions will have a negative effect and shorten the battery life. This also applies to high current rate lithium-ion batteries.

Some lithium-ion batteries fail due to excessive low discharge. If discharged below 2.5 volts per cell, the internal safety circuit opens and the battery appears dead. A charge with the original charger is no longer possible. Some battery analyzers (Cadex) feature a boost function that reactivates the protection circuit of a failed battery and enables a recharge. However, if the cell voltage has fallen below 1.5V/cell and has remained in that state for a few months, a recharge should be avoided because of safety concerns. To prevent failure, never store the battery fully discharged. Apply some charge before storage, and then charge fully before use.