Why Does My Samsung Precedent Phone Keep Freezing Up And Shutting Off On Its Own

The big problem is the battery and how you charge it.  Samsung Galaxy Precedent is  powered by a 1500 mAh Li-Ion battery. Charging and discharging batteries is a chemical reaction, but Li-ion is claimed as an exception. Here, battery scientists talk about energies flowing in and out as part of ion movement between anode and cathode. This claim has merits, but if the scientists were totally right then the battery would live forever, and this is wishful thinking.

The Li‑ion charger is a voltage-limiting device that is similar to the lead acid system. The difference lies in a higher voltage per cell, tighter voltage tolerance and the absence of trickle or float charge at full charge. While lead acid offers some flexibility in terms of voltage cut‑off, manufacturers of Li‑ion cells are very strict on the correct setting because Li-ion cannot accept overcharge. The so-called miracle charger that promises to prolong battery life and methods that pump extra capacity into the cell do not exist here. Li-ion is a “clean” system and only takes what it can absorb. Anything extra causes stress.

Li-ion cannot absorb overcharge, and when fully charged the charge current must be cut off. A continuous trickle charge would cause plating of metallic lithium, and this could compromise safety. Li-ion does not need to be fully charged, as is the case with lead acid, nor is it desirable to do so. In fact, it is better not to fully charge, because high voltages stresses the battery. Li-ion packs that have been under stress are more sensitive to mechanical abuse, such as vibration, dropping and exposure to heat.

Most cells charge to 4.20V/cell with a tolerance of +/–50mV/cell. Higher voltages could increase the capacity, but the resulting cell oxidation would reduce service life. More important is the safety concern if charging beyond 4.20V/cell. The charge rate of a typical consumer Li-ion battery is between 0.5 and 1C in Stage 1, and the charge time is about three hours. Increasing the charge current does not hasten the full-charge state by much. Although the battery reaches the voltage peak quicker with a fast charge, the saturation charge will take longer accordingly.

To minimize stress, keep the lithium-ion battery at the 4.20V/cell peak voltage as short a time as possible.  If a lithium-ion battery must be left in the charger for operational readiness, some chargers apply a brief topping charge to compensate for the small self-discharge the battery and its protective circuit consume. The charger may kick in when the open-circuit voltage drops to 4.05V/cell and turn off again at a high 4.20V/cell.

Here are Simple Guidelines for Charging Lithium-based Batteries

• A portable device should be turned off while charging. This allows the battery to reach the threshold voltage unhindered and reflects the correct saturation current responsible to terminate the charge. A parasitic load confuses the charger.
   
• Charge at a moderate temperature. Do not charge below freezing.
   
• Lithium-ion does not need to be fully charged; a partial charge is better.
   
• Chargers use different methods for “ready” indication. The light signal may not always indicate a full charge.
   
• Discontinue using charger and/or battery if the battery gets excessively warm.
   
• Before prolonged storage, apply some charge to bring the pack to about half charge.
   
• Over-discharged batteries can be “boosted” to life again. Discard pack if the voltage does not rise to a normal level within a minute while on boost. 

Want  the battery to stay alive? Then follow the above guidelines for charging. Do you get good coverage where you are at? Poor signal will keep the phone searching for a tower and kill the battery. Same goes for wifi. Make sure wifi is turned off when not in use and disabledata if you really don't need it.  

---

Posted by USPinay