life of battery=250 charges. Can this be right?

[Andielyn]

While I was trouble-shooting my seemingly low battery life on my Razr Maxx (resolved) a Verizon tech told me that I should routinely completely discharge the battery before charging it because the average battery has only 250 charges, regardless of the battery life remaining when you charge it. What?!? I questioned him about it and said that I was under the impression that this wasn't the case with the newer batteries, and it also contradicts info I've read here in the forums.

So, is this just BS? I've been charging nightly and a few times "topped off" when I knew I was going to be giving it some heavy use (using a golf gps app, for example). With the Maxx battery not being replaceable, I'd hate to think this is accurate info.

[skruid]

Really my d1 battery was good and I charged it every night for two years and then it died and not from the battery going bad, the digitizer went out

Sent from my Galaxy Nexus using DroidForums

[SallyC]

While I was trouble-shooting my seemingly low battery life on my Razr Maxx (resolved) a Verizon tech told me that I should routinely completely discharge the battery before charging it because the average battery has only 250 charges, regardless of the battery life remaining when you charge it. What?!? I questioned him about it and said that I was under the impression that this wasn't the case with the newer batteries, and it also contradicts info I've read here in the forums.

So, is this just BS? I've been charging nightly and a few times "topped off" when I knew I was going to be giving it some heavy use (using a golf gps app, for example). With the Maxx battery not being replaceable, I'd hate to think this is accurate info.

FoxKat addressed this question here and personally, I'd believe him over a VZ tech.

[Fonzz]

I call

[thaDroidz]

250 charges?
Well atleast that's only 250 days well within the 1 year warranty ...

----posted maxx'ed out----

[FoxKat]

FoxKat addressed this question here and personally, I'd believe him over a VZ tech.

That ^^'s not saying much...

[FoxKat]

I call

I believe the issue here is the question of exactly what a charge is. 250 charges if they were 100% capacity to near 0% capacity may be pretty close considering in many cases manufacturers will peg "end of life" at where the battery will only hold between 70% and 80% of original rated capacity. For less than 100% "cycles" (full charge to full discharge), there is a considerable increase in life. For instance, reducing charge to discharge percentages to only 50% each time (half the full charge), increases the number of potential "cycles" to 1,500 (three times). This could be from 100% to 50% and then back, or it could be 75% to 25% and back. Either way, it's a cumulative number of "cycles" that determines the battery's life.

Also noteworthy, in the testing below they discharged to a voltage of 3V each time before recharging. This is the threshold voltage set by the device manufacturer of the device in which the battery is being used, to prevent the battery from deep discharging and going into "protection mode" which causes it to become completely unresponsive to a normal charger. 3V would be somewhere near 0% on the RAZR, but could be slightly higher - perhaps as high as 15%, so it is recommended that you avoid discharging your phone to below 15%, but highly recommended to never let it go to 0% and shut down on its own.

See below (from BatteryUniversity.com)

Figure 1 illustrates the capacity drop of 11 Li-polymer batteries that have been cycled at a Cadex laboratory. The 1500mAh pouch cells were first charged to 4.20V/cell at 1C rate (1500mA) and allowed to saturate to 0.05C (75mA) as part of full charge procedure. The batteries were then discharged at 1500mA to 3.0V/cell, and the cycle was repeated.Figure 1: Capacity drop as part of cycling. A pool of new 1500mA Li-ionbatteries for smart phone istested on a Cadex C7400 battery analyzer. All 11 pouch packs show a starting capacity of 88–94 percent and decrease in capacity to 73–84 percent after 250 full discharge cycles (2010).Courtesy of Cadex

Designed for a smart phone, the packs were already a few months old at time of testing and none of the batteries made it to 100 percent. It is common to see lower than specified capacities and shelf life may have contributed to this. Manufacturers tend to overrate their batteries; they know that very few customers would complain. In our test, the expected capacity loss was uniform over the 250 cycles. All sample batteries performed as expected.

Similar to a mechanical device that wears out faster with heavy use, so also does the depth of discharge (DoD) determine the cycle count. The smaller the depth of discharge, the longer the battery will last. If at all possible, avoid frequent full discharges and charge more often between uses. If full discharges cannot be avoided, try utilizing a larger battery. Partial discharge on Li-ion is fine; there is no memory and the battery does not need periodic full discharge cycles other than to calibrate the fuel gauge on a smart battery.


Table 2 compares the number of discharge/charge cycles a battery can deliver at various DoD levels before lithium-ion is worn out. We assume end of life when the battery capacity drops to 70 percent. This is an arbitrary threshold that is application based.

Depth of discharge	Discharge cycles	Table 2: Cycle life and depth of discharge A partial discharge reduces stress and prolongs battery life. Elevated temperature and high currents also affect cycle life.
100% DoD 50% DoD 25% DoD 10% DoD	500 1500 2500 4700

[TRIKOTRET]

Hey foxkat. Are you a university professor. You remind me of the days in college :-)

Sent from my DROID RAZR using DroidForums

[FoxKat]

Lol. I don't mean to come off like it but it's just a thirst for knowledge and a desire to be helpful. I really need to try harder to tone it down a bit. I don't want people to feel like they're coming to school when they spend time on the forum, but I want to give the best advice I can.

Sent from my DROID RAZR using Tapatalk

[Wopback]

Well you certainly have fans on here. One in- particular....lol...you got good info though, thanks.....

I wouldn't believe the Verizon rep. Remember they work off commission...fk info is legit....

Sent from my Chuck Norris approved DROID RAZR....