MBP battery calibration -- this is ridiculous PC garbage

[m85476585]

Nothing bad will happen if you don't calibrate the battery.

 

[JacaByte]

Except you may get strange reports of the battery gaining capacity, a physically impossible event. Such phenomena has been documented on these very forums.

But I do love how the OP ignores the laws of conservation of mass and energy and states that electrons can be weighed. That's gold, it's like saying gnats can be milked.

 

[m85476585]

To continue the bucket of water analogy:

Think of a battery like two buckets, one raised up above another. A full battery is represented by the top bucket being full of water. As you discharge the battery, the water flows through a circuit (hoses) and does work (maybe spinning something). It is then collected in the bottom bucket. To recharge the battery, water is pumped from the bottom bucket to the top bucket.

In a battery, there is no way of knowing how much total water is in the buckets without calibration.

 

[PinkyMacGodess]

Some information on Lithium-Ion Batteries...

A lithium-ion battery (sometimes Li-ion battery or LIB) is a type of rechargeable battery in which lithium ions move from the negative electrode to the positive electrode during discharge, and reversely when charging. During discharge the negative electrode is the anode where oxidation takes place and during charge it turns into the cathode where reduction takes place. This functional meaning of the words anode and cathode is however widely ignored in the slang of battery-specialists: "anode" means negative electrode and "cathode" means positive electrode. For consistency, the latter practice is followed in this article. Different types of lithium-ion batteries use different chemistry and have different performance, cost, and safety characteristics. Unlike lithium primary batteries (which are disposable batteries), lithium-ion cells use an intercalated lithium compound as the electrode material instead of metallic lithium.

Disadvantages:

A disadvantage of lithium-ion cells is their poor cycle life: upon every charge or recharge, deposits form inside the electrolyte that inhibit lithium ion transport. Over time, the capacity of the cell diminishes. The increase in internal resistance affects the cell's ability to deliver current. This problem is more pronounced in high-current applications. The increasing capacity hit means that a full charge in an older battery will not last as long as one in a new battery (although the charging time required decreases proportionally, as well).

Also, high charge levels and elevated temperatures (whether resulting from charging or being ambient) hasten permanent capacity loss for lithium-ion batteries. The heat generated during a charge cycle is caused by the traditional carbon anode, which has been replaced with lithium titanate. Lithium titanate has been experimentally shown to drastically reduce the degenerative effects associated with charging, including expansion and other factors

At a 100% charge level, a typical Li-ion laptop battery that is full most of the time at 25 °C or 77 °F will irreversibly lose approximately 20% capacity per year. However, a battery in a poorly ventilated laptop may be subject to prolonged exposure to higher temperatures, which will shorten its life. Different storage temperatures produce different loss results: 6% loss at 0 °C (32 °F), 20% at 25 °C (77 °F), and 35% at 40 °C (104 °F). When stored at 40%–60% charge level, the capacity loss is reduced to 2%, 4%, 15% at 0, 25 and 40 degrees Celsius respectively.

Internal resistance

The internal resistance of lithium-ion batteries is high compared to other rechargeable chemistries such as nickel-metal hydride and nickel-cadmium. Internal resistance increases with both cycling and chronological age. Rising internal resistance causes the voltage at the terminals to drop under load, which reduces the maximum current that can be drawn. Eventually the internal resistance reaches a point at which the battery can no longer operate the equipment for an adequate period.

Li-ion batteries are not as durable as nickel metal hydride or nickel-cadmium designs, and can be extremely dangerous if mistreated. They may suffer thermal runaway and cell rupture if overheated or if charged to an excessively high voltage. In extreme cases, these effects may be described as "explosive." Furthermore, they may be irreversibly damaged if discharged below a certain voltage. To reduce these risks, lithium-ion batteries generally contain a small circuit that shuts down the battery when it is discharged below about 3 V or charged above about 4.2 V. In normal use, the battery is therefore prevented from being deeply discharged. When stored for long periods, however, the small current drawn by the protection circuitry may drain the battery below the protection circuit's lower limit, in which case normal chargers are unable to recharge the battery. More sophisticated battery analyzers can recharge deeply discharged cells by slow-charging them to reactivate the safety circuit and allow the battery to accept charge again.

Guidelines for prolonging lithium-ion battery life

* Lithium-ion batteries should never be depleted below their minimum voltage (2.4 to 2.8 V/cell, depending on chemistry). If a lithium-ion battery is stored with too low a charge, there is a risk that the charge will drop below the low-voltage threshold, resulting in an unrecoverable dead battery. Usually this does not instantly damage the battery itself but a charger or device which uses that battery will refuse to charge a dead battery. The battery appears to be dead or not existent because the protection circuit disables further discharging and there is zero voltage on the battery terminals.

* Lithium-ion batteries should be kept cool. They may be stored in a refrigerator.

* Lithium-ion batteries degrade much faster if stored in high-temperature areas.

Restrictions on transportation

As of January 2008, the United States Department of Transportation issued a new rule that permits passengers on board commercial aircraft to carry lithium batteries in their checked baggage if the batteries are installed in a device. Types of batteries affected by this rule are those containing lithium, including Li-ion, lithium polymer, and lithium cobalt oxide chemistries. Lithium-ion batteries containing more than 25 grams equivalent lithium content (ELC) are exempt from the rule and are forbidden in air travel. This restriction greatly reduces the chances of the batteries short-circuiting and causing a fire.

Additionally, a limited number of replacement batteries may be carried on as luggage. Such batteries must be sealed in their original protective packaging or in individual containers or plastic bags.

On 2009 fall, at least some postal administrations restricted air shipping (including EMS) of lithium batteries, lithium-ion batteries and products containing these (e.g. laptops, cell phones etc). Among these countries are Hong Kong, and Japan.

Interesting...

 

[kunfunyu]

I have a Core i7 15" MBP... and I am getting poor battery life. Not THAT poor, but poor compared to the advertised times. Anyone only getting 4-5 hrs on 1/2 brightness and only basic browsing/music playback? Does the matte screen or i7 processor reduce battery times?

 

[jake.f]

I think maybe the OP has accepted how stupid he/she looks and is off hiding somewhere now

 

[mac2x]

Scientifically, a battery contains a certain number of electrons. As you use the battery, the electrons evaporate, causing a current. The point is that these electrons have mass. Now all you need to do is measure that mass of the battery and do some of your fancy multiplications, integrations (be sure to integrate along the curve) and differentiations stuffs to measure the charge.

The hard part is measuring the mass accurately. For this you would need to invent a device to measure the bending of light in vicinity to the battery.

Voila, problem solved.

Please tell me you are joking, because that is completely and utterly wrong.

 

[Mark Booth]

It feels ridiculous having to go through this battery calibration process.

Apple should be above and beyond this PC crap.

On top of this discharging a LiIon battery fully is *bad* for it and *decreases* battery life. But no, Apple has to stick a pathetic microchip in the battery that requires you to go through a full charge/discharge cycle to "calibrate" it.

Pathetic.

I'm really disappointed about this.

Someone else needs the:

Mark

 

[mac2x]

Someone correct me if I'm wrong, but doesn't Apple use LiPoly batteries rather than ordinary Li-ions?

 

[Azathoth]

Someone correct me if I'm wrong, but doesn't Apple use LiPoly batteries rather than ordinary Li-ions?

I think you're right, but LiIon and LiPo are very similar (some discharge rate advantages and FF advantages for LiPo, AFAIK) - moreover each battery OEM (not Apple themselves, but their suppliers) makes their own little tweaks, but the principles for the battery technology remains the same and are different to NiCd, NiMH and Pb-acid.

But the average consumer just remembers some hearsay about 'rechargable' batteries and applies their lack of knowledge to all rechargables.

 

[alphaod]

It feels ridiculous having to go through this battery calibration process.

Apple should be above and beyond this PC crap.

On top of this discharging a LiIon battery fully is *bad* for it and *decreases* battery life. But no, Apple has to stick a pathetic microchip in the battery that requires you to go through a full charge/discharge cycle to "calibrate" it.

Pathetic.

I'm really disappointed about this.

That's not PC garbage; the only way to calibrate the gauge is to a full cycling. I have Thinkpad; there is an option to reset the battery gauge; what does it do? I fully charges, discharges to empty, and fully recharges it. Sure this process is automated on the Thinkpad, but the idea is the same as what Apple is doing. They probably just don't want to provide an utility in fear that people will think their batteries need calibration.

 

[mattrothcline]

Scientifically, a battery contains a certain number of electrons. As you use the battery, the electrons evaporate, causing a current. The point is that these electrons have mass. Now all you need to do is measure that mass of the battery and do some of your fancy multiplications, integrations (be sure to integrate along the curve) and differentiations stuffs to measure the charge.

The hard part is measuring the mass accurately. For this you would need to invent a device to measure the bending of light in vicinity to the battery.

Voila, problem solved.

Thank you - this is the funniest thing I've read in a long time.

 

[mattrothcline]

On top of this discharging a LiIon battery fully is *bad* for it and *decreases* battery life. But no, Apple has to stick a pathetic microchip in the battery that requires you to go through a full charge/discharge cycle to "calibrate" it.

By the way, even when your Mac shows the battery capacity at "0%", it's not fully discharged. The only way to fully discharge it is to run it down to 0% and then let it sit for a couple of months with no charge.