BU-706: Summary of Do’s and Don’ts

Discover ways to extend battery life by following simple guidelines.

“What can I do to keep my batteries longer?” many people ask. As folks stay fit by refraining from smoking, lowering sugar intake and exercising, so also can battery life be extended. There are no hard numbers as to how effective good care is, but the proof is in examples where packs were issued as personal goods as opposed to stock items. Personal care almost always wins

Table 1 summarizes how to prolong battery life through proper attention. Because of similarities within systems, the chemistries are limited to lead, nickel and lithium.

Battery care

Lead acid: Flooded, sealed, gel, AGM

NiCd, NiMH

Lithium-ion: Cobalt, manganese, NMC

Best way
to charge

Apply saturated charge to prevent sulfation; can remain on charge with correct float voltage.

Avoid getting battery too hot on charge. Do not leave battery in charger for more than a few days Subject to memory.

Partial and random charge is fine; does not need full charge; lower voltage limit preferred; keep battery cool.

Charge methods

Constant voltage to 2.40–2.45/cell, float
at 2.25–2.30V/cell. Battery should stay cool; no fast charge possible. Charge time 14–16h.

Constant current, NiCd can be fast charged without stress;  trickle charge at 0.05C.
Slow charge  = 14h
Rapid charge = 3h*
Fast charge   = 1h* NiCd

* Recommended

Constant voltage to 4.20V/cell; no trickle charge; battery can
stay in charger.
Rapid charge = 3h*
Fast charge = 1h

* Recommended


Can endure high peak currents. Avoid full discharges. Charge after each use.

Do not over-discharge with a heavy load; cell reversal causes short. Avoid full discharges.

Prevent full cycles, apply some charge after a full discharge to keep the protection circuit alive.

How to prolong battery

Limit deep cycling; do not deep-cycle starter battery. Apply fully saturation charge. Avoid heat.

Discharge batteries that are in regular use (mainly NiCd) to 1V/cell every 1–3 months to prevent memory.

Keep cool. Operate in mid SoC of 30–80%. Prevent ultra-fast charging and high loads (most Li-ion)

Transport Flooded: Class 8 restrictions, provide “corrosive” label.

Non-spillable: Class 8 exempt.
Prevent short by placing battery in clear plastic bag.

See BU-704: How to Transport Batteries
Loose cell under Section II must be shipped at 30% state-of-charge.

See BU-704a Shipping Lithium-based Batteries


Keep cells at >2.05V. Apply topping charge** every 6 months to prevent sulfation.

Store in cool place; NiCd stores for 5 years; prime before use

Store at 40% charge in cool place (40% SoC reads 3.75–3.80V/cell). Do not go below 2.0V/cell.


Toxic. Do not dispose. Electrolyte corrosive. Profitable to recycle.

NiCd:  Do not dispose.
NiMH: May be disposed in low volume

Low toxicity. Can be disposed in low volume. Best to recycle.

Table 1: Do’s and don’ts summary of how to use, maintain and dispose of batteries.

**  Topping charge is applied on a battery that is in service or storage to maintain full charge and to prevent sulfation on lead acid batteries.

Caution: Under no circumstances should batteries be incinerated, as fire can
cause an explosion. Wear approved gloves when touching electrolyte.
On exposure to skin, flush with water immediately. If eye exposure occurs, flush with water for 15 minutes and consult a physician immediately.

Last updated 2018-04-10

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Comments (136)

On November 9, 2010 at 10:10pm
Erick wrote:

I still have a doubt here, It’s safety or not to the battery if I remove it from the laptop while it’s running? Or I need to turn off the laptop in order to remove the battery?

On December 4, 2010 at 11:30am
Jeff wrote:

It is generally safer to remove and replace the battery when the computer is turned off, but as long as the computer is plugged in there should be no major problems.

On December 19, 2010 at 7:06am
moza ahmed wrote:

me 2 .. i still remove the battery while laptop is running .

& i think that is good way ,, isn’t it ?


On January 3, 2011 at 5:27pm
Enrique wrote:

What does 80% depth of charge mean? Should I charge until 80% then use, or should I charge to 100% and then use until 80% then recharge?

On January 6, 2011 at 5:12am
Boris wrote:

That’s “80% depth-of-discharge”, DIScharge, not charge. Thank you,

On January 14, 2011 at 12:46am
Michał Surowiecki wrote:

Thanks, these are helpful information:) But what about Li-Polymer batteries, how to charge them?

On January 14, 2011 at 8:56am
Cadex Electronics Inc. wrote:

@Michal - LiPo charging rules follow the Li-ion column.

On January 20, 2011 at 4:32am
nitin wrote:

should we use laptops with only charged battery power or run laptops with direct powers along with batteries to ensure more life for batteries.

On January 21, 2011 at 6:13am
Riezknoe wrote:

Thanks….btw does using the battery while charging ‘drain’ the battery????
eg.talking on mobile phone while charging….

On January 21, 2011 at 9:51am
Boris wrote:

Sometimes battery-powered devices use battery power even they are charging, so they “drain” batteries when charging.
Some don’t, they use external power source such as power from the charger, then these kinda devices don’t “drain” batteries when charging.

On January 21, 2011 at 9:54am
Boris wrote:

“Sometimes battery-powered devices use battery power “
I mean devices that always powered by battery power when charging.

On January 24, 2011 at 9:01am
Riezknoe wrote:


On February 7, 2011 at 7:40pm
Craig wrote:

Is it OK to recharge a Li-ion battery immediately after use?  While it’s still warm?  I remember that was the case with NiCd batteries when racing RC cars.

On February 10, 2011 at 10:48pm
Boris wrote:

Craig, if you do not need to use the device immediately, it would be very kind of you to let it cool down before charging.
While charging any kond of batteries, it will warm up or heat up, so you guys need to do something to cool them down.

On February 10, 2011 at 11:01pm
Boris wrote:

nitin, there are a few circumstances:
If the AC incoming power are stable where you work at with the laptop, you can discharge your battery to 30~40% power left by using the power of the batt., then put the batt. away your laptop to storage them;
If the AC incoming power are quite not stable, or there’s a scheduled power off where you work at, you’d better keep them in the laptop. That’s because you may / will need them any minute.

On March 11, 2011 at 9:11pm
samir wrote:

how much battery charge level should be left off in battery when not using laptop battery for 1 or 2 weeks or i mean instead of using battery i use external power. will this help in maintain long life of a laptop battery? i mean to say put battery into laptop when u away from power source.

plz tell if using laptop without battery affect’s its performance?
is it the good practice?

also please tell is it good to perform full recharge cycle in cell phone batteries with 1500 mah capacities or lower???
how often should we charge cell phone batteries for their long life and performance?

On April 19, 2011 at 12:34pm
fhhuber wrote:

Regarding partial charging a Li based battery:

In Radio Control applications the “LVC” (low voltage cutoff) is often based on the voltage of the pack when it is plugged in.  Thus a partially charged pack can result in excessively low cut-off which will damage the battery.  Always fully charge a battery used to power a radio controlled model.

Also note that LiPo is easier to damage through improper charging or over-discharging than Lion or LiFe/LiFePO4.  Thus this page needs updating and separate columns for the different types of Lithium based cells… or a separate page just for Li based cells.

On April 19, 2011 at 3:04pm
Rob wrote:

My laptop has an option to turn off the battery charger while remaining plugged in (and operating).

While I understand removing the battery is the best way to prolong life, I prefer to keep my battery in the laptop so I don’t lose work in case of a power glitch or failure. Each time I start my computer, it reminds me my battery is not being charged and tells me how much charge is left. In two weeks, it has already dropped to 88% charge and my computer is brand new.

My question is, if I want to prolong the batteries life, at what charge level should I turn the charger back on? How long would you expect it to take to reach that charge level?

On May 17, 2011 at 2:09pm
Christine wrote:

Does brand matter in terms of battery/charger interaction?
I need to buy a charger for a CRV3 battery, and I was wondering if there is a problem charging generic batteries with a Kodak charger and vice versa.

On May 20, 2011 at 3:43pm
Tommy wrote:

is it okay to use laptop directly from AC power? is there any downside other than there’s a scheduled power off

is it right that removing the battery is the best way to prolong life??

On June 3, 2011 at 10:39pm
Angel wrote:

“apply some charge after a full discharge”
so what should I do? discharge until 20%, then plug in the A/C immediately and countinue using, or shut down, let it cool, then charge?

On July 13, 2011 at 2:43pm
Egberth wrote:

i like that web ,it has been answered my question thanks a lot

On July 21, 2011 at 8:40am
Glorianne wrote:

I have one question which I would like some assistance on:

My camera uses a battrey NB-4L, 3.7V, 760mAh(Li-on). Now I would like to replace the battrey as the lifetime of the battrey has become too short.

Would a battrey with a higher capacity [NB 4L, 3.7V 900mAh (lion)] be used on the camera or will it damage the camera (if it works at all cause I have no idea).  I would appreciate if someone could kindly advice on this. Thanks in advance!

On August 13, 2011 at 6:05pm
Lynn wrote:

I have the same question as Glorianne too.
My camera uses the battery NB-4L, 3.7V, 760mAh(Li-on). If I use a higher capacity battery, NB 4L, 3.7V 900mAh (lion)] - will it damage the camera?


On September 16, 2011 at 2:49am
Randi James wrote:

I have few quetions on charging cell phone batteries.  Is it gppd tp keep unplugging and plugging back in the phone while it is being charged? (like to move it to different spot) or should you plug it in and leave it untill it is fully charged. 

Is it good for the battery to just charge it for few minutes at a time, just enough to last short bit.  (battery is low so charge for 30 min to get some charge on it, then keep doing that over and over.)

On September 19, 2011 at 1:34am
Boris wrote:

To Randi James

Sometimes battery-powered devices use battery power even they are charging, so they “drain” batteries when charging.
Some don’t, they use external power source such as power from the charger, then these kinda devices don’t “drain” batteries when charging.

“Sometimes battery-powered devices use battery power “
I mean devices that always powered by battery power when charging.

On October 26, 2011 at 10:21pm
Lola wrote:

Hi, just got a new camera with li-ion battery and was wondering if i should charge it before i use it (and if so, then for how long) even though it says it’s fully charged? I remember having to charge cell phone batteries for many numbers of hours before use in the past.

On October 28, 2011 at 9:54pm
Boris wrote:

To Lola:
The Li-ion battery?If the power is not full, just charge it. When it’s full, ordinarily it would stop charging. See the table atop for deails.

On October 30, 2011 at 10:36pm
Vanessa wrote:

I read somewhere if I have a chance to charge the Li-Ion battery, I should just do it. So for those batteries basically always leave them on the charger?

So, I have a Dell laptop with Li-Ion that I got last year. I have a 6 cell and 9 cell battery. Should I keep my battery constantly charging or should I go to 100% and unplug it and then charge it again when it says battery is low or maybe half way?
Is it the same for my Droid 3 phone Li-ion battery? I charge it every night and it doesn’t get below 50%, 40% or 30% rarely.

On November 12, 2011 at 5:48am
Charles Fisher-Post wrote:

My UL V-2833 Class 2 Battery Charger does not work (or, at least the charging lights don’t turn on), and I never even used it once! I put the batteries in the unit in pairs, like the instructions say.

However, when I traveled with it, I stored the batteries in the unit itself, unplugged of course. My question is—can storing rechargable batteries in the unplugged recharging unit cause it to break? That’s the only explanation I can summon, other than faulty mechanics.

On November 15, 2011 at 6:49am
prince wrote:

I use acer inspire 5516…my uncle gave it 2 me.
The battery take an hour to get fuly chargd(dn’t knw if its geting weak). wen its ful i stil leave it on AC til i’m tru.
Wen i unplug it, i use d main battry to 20%.
Is it advicable?

On November 18, 2011 at 4:32pm
omed wrote:

i bought laptop hp dv5 before 3 years ago ,so right now during using the lap top an alarm comeing talking about that my battrery should be replacement ,and befor i were recharging in when it need that ,otherwise i were used it without pluging.so could you guide me to the right way.


On November 20, 2011 at 6:27am
Ryan wrote:

I bought 2900mAh AA batteries and a 200mA charger. After 8 hours the led’s on the charger go off and it switches to a trickle charge. When I do the math it says they need to charge for 17 hours. Do I reset the charger to charge through another 8 hour cycle or do I let it continue on the trickle charge for the remaining time?


On December 9, 2011 at 1:36pm
Guillaume wrote:

Can anyone answer my question ? I am wondering how the temperature is affecting the internal resistance of the battery. I know that a lower temperature will raise the internal resistance and vice versa.

My question is more the “by how much” part. For instance, at 25°C, the internal resistance of my lead acid 12V 16AH battery is 4mH. What will be the internal resistance of that battery at -40°C ?

Pretty sure it depends on the battery’s manufacturer but is there any way to estimate this value other then testing at -40°C ?

On January 3, 2012 at 12:09pm
ali najafi wrote:

i still can’t find out how to charge my lithium battery for the first time?some of my friend told me to charge it 12 hours and some others say just charge it for 3 hours?how could i know what’s best for the first time?

On January 9, 2012 at 6:17am
j.sri lakshmi wrote:

is it possible to charge a battery using micro wave?

On February 5, 2012 at 7:51pm
roger samala wrote:

we ordered Stationary Industrial Single cell Vented Type Lead Acid (VTLA) batteries 900 AH. Since the standard procedure in shipping VTLA is in dry charged condition and when we received the shipment it is already filled-up with electrolyte solution from the factory (France) and delivered here in Philippines. Upon inspection of the batteries we found formation of white powder at the bottom of the plastic casing. Does this indicate that the batteries are old stock?....have been in stock with electrolyte for months… we are using 48VDC for our Repeater sites and this is the first delivery (replacement of of our old batteries) consisting of 96 sites. Question >>> Do we have to accept or reject said said shipment ?

On February 17, 2012 at 9:54pm
rajvi wrote:

Why mobile battery is of rating 3.7 v?

On February 22, 2012 at 6:06am
aj wrote:

is it uk if you used your netbook full without unplugging then used it? ahm,. i unplugged it after using.

On February 22, 2012 at 6:08am
aj wrote:

di kaya maless ang capacity of that?? while using it then it is fully chareg??

On February 23, 2012 at 3:09am
jollyoger wrote:

VTLA or Vented Type Lead Acid battery should be delivered DRY CHARGE. Since you will transport it to other place I think you need to get clearance to concerned environmental agencies of the countries where it will be delivered. It is the standard procedure to make sure that the batteries are brand new and not second hand. There will be no basis for the end user to know that the batteries have been stored for a long time.

On February 24, 2012 at 7:34am
teresa boling wrote:

Can you tell me what kind of battert is in a lap top.Lead acid,Nickel based or Lithium?  its a new hp. thanks teresa

On March 1, 2012 at 7:29am
John Paul C. wrote:

There are some questions here that were not being answered. The msot common question is “Is it OK to use the charger while still the battery is connected and being USED”?. Well, for me, just a piece of an advice, let the notebook charge battery while you are using it, even if it is fully charged. That is if the battery is Li-Ion. That’s one of the features Li-Ion has compare to those NimH or NicAD. That is how I prolonged my battery from my Toshiba for almost 3 years now, going 4 years.

On May 13, 2012 at 7:48pm
Adrian wrote:

Don’t ever use direct power to your laptop if your battery removed from laptop. If the house electricity sudden off, it will give damage to laptop motherboard. My last laptop is useless now because the motherboard is not functional now. It was because i only use direct power, and when the electricity suddenly shut down, it also shut my laptop. then when i open it back, the motherboard crash.

On June 22, 2012 at 11:22pm
ishmAEL JAFI wrote:

is it ok to charge phone battery using the universal charger, the one that charges the battery out of the phone? And can i connect a charger direct to the back of my phone if my phone no longer charges thru the port? Thanx gguys

On June 27, 2012 at 5:22am
Florence wrote:

What’s the danger of leaving my camera still charging if it’s already fully charged.
PS:It still works but I cannot upload photos to my laptop anymore :/
Please help me!

On June 30, 2012 at 11:09pm

If someone overfilled the sealed Ni-Cd batteries,what are the danger may be there?

On July 4, 2012 at 11:58pm
jaiprakash wrote:

after given freshening charge of Ni-Cd battery always taken 10 amp current why???

On July 15, 2012 at 9:18pm
narbada singh wrote:

please explain me weather i should keep charging my laptop while using it or remove it once it is charged

On July 18, 2012 at 9:29am
Eswar wrote:

Sir, Can I always Use my Laptop on AC power, after removing my Exhausted Battery? Will it make any harm to my Laptop? Pls advise

On August 16, 2012 at 7:52pm
Haz wrote:

Hi my laptop charger was damaged about two weeks ago and the charge on my laptop was completely gone I finanly found the same charger it’s been nearly 12 hours since iv been charging my laptop and it still does not turn on how long would I have to charge it my laptop has been dead for about two weeks now. Thanks

On September 1, 2012 at 9:32am
Muhammad zeeshan wrote:

I want to charge a battery which is being used by a DC motor at the same time
What should be my precautions?
And will the polarity of the mOtor be reverse too in case of charging?
At what voltage should i charge the battery of 12 volts
If its a normal acid water battery?

On September 10, 2012 at 7:32am
BR wrote:

Is it safe to charge a smartphone while it is in an Otterbox case?  I have heard that will cause excessive heat which will damage the battery or shorten its lifespan?

Thanks for your help..

On September 27, 2012 at 10:08pm
murray c wrote:

The following advice is in a portable radio users manual. The batteries are Ni Mh which do not have memory effect so why discharge to condition and does constant trickle charge age battery?

• Leaving the battery on charge
You can leave a battery/radio in the charger once charging is
complete. Leaving a battery in the charger will not
overcharge or damage it.
You can remove a battery/radio from the charger at any time
without harming the battery, the radio, or the charger.
When you return the battery/radio to the charger, charging
is automatically resumed.
• Conditioning NiMH batteries
‘Condition’ a NiMH battery every three months to extend its
shift life. Conditioning enables a battery to hold its charge
for longer.
To condition a NiMH battery:
■ Leave the radio switched on and ignore the ‘low battery’
warnings from the radio.
When the radio switches itself off, the battery is fully
discharged and ready to be recharged.

On October 31, 2012 at 6:51am
Amzi Java wrote:

in the beginning of this year, my laptop battery used to stay for up to 2 hrs. now, in Oct, it barely lasts up to 55mins. please, give me some practical tips on the use of batteries, especially for laptops and torchlights, to ensure their long life.

On February 23, 2013 at 2:50am
raj wrote:

should the charger be connected even if battery is fully charged?

On February 26, 2013 at 7:15am
Carlos Paixao wrote:

I find it article very awesome, but Its kinda confusing to me.

The other article was saying that we might avoid keep batteries on cradle charging when it gets full charged for keeping it away from parasite cycles or mini cycles.

But here you said for li-io “battery can
stay in charger”.

So what is the real, I can keep it on dock or travel charger while using it or no?

Consider LI-IO and LI-PO battery for this.

On April 15, 2013 at 12:06pm
Sara wrote:

Is it bad if I keep my Mac laptop always charged? (Like it’s always connected to its charger) Does it drain from the main battery life after awhile or would you just use the electricity coming from the charger?

On April 16, 2013 at 3:18am
Zeeshan wrote:

No its aafe to keep ur mac book charged
All laptops have an internal tripper that will turn off caharging to the battery automatically when full

And yes when the charger is connected the battery wil not drain
It will use power from charger

On May 8, 2013 at 4:25am
windie wrote:

hello, just wanna ask, I have just bought new mobile phone with new battery, and after a week, I couldn’t charge it to full (100%), it would start charging slowly after 90%, not even 1% per hour, is it normal? or should I get new batteries?

I did read that for Li-ion battery it would be best to not charge fully, simply wonder if my battery is broken or something

On October 9, 2013 at 2:49am
Jhonsone wrote:

I’ve a buildin battery notebook can I leave it pluggin when using?

On December 15, 2013 at 11:41pm
Renjith wrote:

is it advisable to charge the battery of android mobiles using data cable connecting to a laptop or PC without directly connecting to AC power supply.

On December 16, 2013 at 6:03am
Zeeshan wrote:

It really doesnt matter
Becoz if u read the instuctions from ur ac charger
U will see that both ac charge abd the usb port of ur pc gives out 5V dc
It is advisable to use ur pc usb port as a charger if u have fluctuating AC supply at ur home

On March 2, 2014 at 2:14pm
Steven wrote:

So I have started making pouch cell batteries and am having issues charging them. I put the electrolyte in (glove box) and then do the final seal. I connect it to a battery analyzer and set it to cycle (formation?). But it only gain capacity on constant voltage charging, and when it’s on either constant current charge/discharge, it immediately stops and goes to the next step. What could be going wrong?


On April 19, 2014 at 9:36pm
352 wrote:

What quantity of water is damaged if I dispose a battery there?

On April 20, 2014 at 1:14am
Zeeshan wrote:

If u disposed a battery in water then the ph of water goes towards 0 but the solution is very dilute so in short no much harm done

On June 20, 2014 at 12:19pm
Cornelius wrote:

Is it good to play games or use the laptop while charging the battery ....plz help me ....!!!!

On June 25, 2014 at 11:28am
dosmastr wrote:

avoid full discharges?

If you only kill it 50%, then charge it, thats how you end up with memory.

I have always been told run a nicad until its DEAD DEAD DEAD otherwise you will develop a memory

On August 23, 2014 at 3:19am
James Rv. wrote:

Is it trure that charging your cell phone while making a call could cause your device to explode?

On September 2, 2014 at 10:30pm
Riad Moucarry wrote:


I have a car battery for home use, 12V 55 Ah, attached to it are LED for room lighting and a ADSL router to access the internet.

My question, can I keep the charger always attached to the battery in order to charge it whenever the 220V is available OR that is not good for the battery?

Best regards.

On September 3, 2014 at 4:59am
Zeeshan wrote:

Yes u an leave the charging on if the battery is not dry battery and the charger isnt available all the time but i recommend u buy a 12 v over charge protection kit or u can make it urself
Its really easy and cheap to buy or build
Buy a trickle charger if u do so

On September 9, 2014 at 11:28pm
Raghu wrote:


The discussion here was very useful as I got new laptpo which has Lithium Ion Battery. I have gone through all the comments while I got most of the answer but I did not find the exact answer to suit my needs, here is my concern can you please let me know how to handle this situation?

I work on Laptop most of the times from Home, there isn’t power issue however the power oges off all the sudden without any notice as there are unschedule power cuts. Now as I use laptop most of the times it is ok to keep the AC Power plugged in whlile Battery inside? If yes then shoudl I keep discharging Battery manually by switching off power? Please let me know how to handle this situation?

1) Keep working with AC Power on for continously for a month and then discrhage the battery fully and then continue or
2) Keep working with AC Power and keep discharging the batter partially everyday? and then again continue AC power?

Just guide me on this, this would be a very valuable help for me.

On September 10, 2014 at 8:09am
Zeeshan wrote:

U cab keep the ac charging on at all times when available. Ur laptop battery will however go down after 3 years…. No worries
Just avoid fast discharge/drainage of battery

On September 10, 2014 at 8:16am
Raghu wrote:


So you mean no need to keep the battery discharge at frequent intervals? So you mean even if we try to discharge it regularly the Batterly life lasts for only 3 years?

Also, just confused with your comment “Just avoid fast discharge/drainage of battery”, do you mean I should not discharge it completely?

On September 10, 2014 at 10:00am
Zeeshan wrote:

i meant that you can keep the charging of the laptop ON whenever u have AC supply at ease

these lithium ion batteries have charging cycles which best work when the battery is charged slowly, charged above 90%, used till below 20% (or even 10%)...never fully discharge the battery

what i meant with fast discharge was that when the charger is not available dont play heavy games or run heavy softwares that drain the battery very fast

in short, fast charging and fast discharging is harmful for battery
and these laptop batteries will last upto 3 years atmost with full care

On September 10, 2014 at 11:20pm
Raghu wrote:

Thanks for your help, it was really helpful for me to have my new Laptop Battery understand and how to maintain.

On October 27, 2014 at 1:22am
ronil wrote:

Need an advice. I am using my android phone 3.5 hrs straight game leaving 15%-20% juice. after that i charged it to 100% always. Then after fully charged, rest for 10 mins and then play again straight 3.5hrs. In other words, i am charging my phone twice a day. is that okay?  Thanks in advance.

On October 27, 2014 at 5:51am
Zeeshan wrote:

Well it is harmful for ur fone battery (this fast charging and fast discharging) because ur battery has a limited number of cycles and according to u that u are using 2 cycles per day
However its not that big of a deal coz phone batteries are cheap
Ur welcome

On November 1, 2014 at 4:50am
tushar wrote:

Well ...after reading the entire discussion being a noob I was able to understand most of the things clearly but some doubts remains still unclear
1.without any sort of repititive answers plz tell me should I fully charge my dell inspiron notebook everytime time I put it on charge(I asked this because it is written above that full cycles are not required)....also if I dont have any problems related to how much time is taken for full charge.
2.i have read at most sites that li-ion batteries have fixed no. Of charge cycles so if I just charge it randomly wouldn’t its cycles be reduced…on the contrary to which full charge cycles will increase life( i mean chrging when battery is about 20% untill its fully charged every time).
3.also while perForming heavy tasks the laptop gets heated hence affecting battery..so please suggest some techniques so I can easily do heavy-TasKiNg《●)....And also doesn’t affect my battery.
4.pLEase do answers my 1. And 2. Queries. ..as tgey r the most important ones.
5.And…is it ok if I use my laptop in between charging. ....
A big thanx in advance to all the guys and girls involved in this site….

On November 1, 2014 at 6:24am
Zeeshan wrote:

short and to the point ans to your questions:P
being an electrical engineer and programmer

1.ans: u can fully charge ur laptop, it will be off no harm to the battery
2 ans: yes there are fixed no. of cycles (about 3000+ cycles) but its no absolute rocket science that u are using ur cycles when charging randomly, but in short u r upto some extent.
3 ans: i have an inspiron 1545, an inspiron n4050 and a inspiron 14r5421 so there is no way to decrease the heat if u r performing heavy operations. just be careful not to block the fan
4. i hope i did answer upto ur level
5.its 100% ok using laptop while charging or while fully charged

On November 1, 2014 at 7:10am
tushar wrote:

Thanx again zeeshan…
And tess I remember askin same questions fron diff. People and always get different answers so…can u tell me what should be battery backup after full charge(I have dell inspiron 3542 4cell 40w battery).it gives about 4hours till its down from 100to20% after im continuously plaing movies….

On November 1, 2014 at 7:13am
Zeeshan wrote:

well i have a doubt about ur 4cell battery coz there are normally 6, 9 or 12 cell batteries in all laptops

u have mistaken the 6 for 4 cell i assume
however thats great timing
becoz my inspiron is a corei5 touch screen and goes 4.5hours max on VLC player on movies

On November 1, 2014 at 7:23am
tushar wrote:

I might have but just checked full specs on dell support and it says 4c battery…so

On November 1, 2014 at 7:27am
Zeeshan wrote:

well i checked also
ur rite
the timing is great by the way

On November 10, 2014 at 11:30am
paris wrote:

hi. i have a lenovo g510. i didnt charge it for 12 hours the first time i used it.so now, battery work for about 2.30 hours when it supposed to work for 4.30 hours (for medium use). now that i charged it for several time (when it was 30% or lower) is it ok to chrge it for 12 hours?

On November 10, 2014 at 6:04pm
Zeeshan wrote:

Forget about the charging history now
Just charge it till the battery is full
And use it
Will work just fine

On November 11, 2014 at 3:20am
paris wrote:

Thanks. But i did it as you said and problem is it didnt work more than 2.30

On November 11, 2014 at 7:54am
Zeeshan wrote:

Then u should contact the manufcturer if the problem still prevails
Coz 4 cell batteries are also v.gud indeed

On December 6, 2014 at 10:17pm
cherie wrote:

Hi, I have read conflicting advices on battery care and would like to seek clarification. I am using Lenovo X1 Carbon and mostly work from home and office with a stable power supply. You mentioned earlier in the comments that it is not harmful to the battery to leave the charger on while using the laptop and allowing the battery to remain fully charged. (Is this okay in the long run eg, constant usage with the charger on for 8 hours a day?)

Also, I read from other sites that it is better to leave the battery with 40% - 80% charge (ie charge till 80%, unplug the charger and charge again at 40%) Is long term partial discharge harmful to the battery?

Please advise which method is better for the battery or let me know if you have other recommendations. Thank you so much!

On December 6, 2014 at 10:41pm
Zeeshan wrote:

Old laptops had this problem that if u leave them on power, they would ruin the battery
But these new machines have a very efficient over charge protection system
Now i know its true that the 80-40% story is true and is 90-20% to be exact.
But i advise u the best possible way of applicable solution that is

U use the laptop while on charging normally, and must discharge it fully below 10% once a month to keep ur battery healthy.
Thank u

On January 22, 2015 at 10:03am
abdul wrote:

I hv a question please.
Can I use dell laptop with plugging in charger always? Is there any problem in battery? Thanks

On January 22, 2015 at 11:04am
Zeeshan wrote:

no there is no problem in it

On February 6, 2015 at 12:04am
Ish wrote:

Is this applicable to android batteries?

On June 9, 2015 at 1:26am
jessa lorania wrote:

i have a new laptop and i charged it less than 5 hours on first charge, is it bad? what should i do?

On June 29, 2015 at 4:11am
Geoffrey Tloubatla wrote:

I have a 12volts deep cycle battery that charges up to 11.59 volts. What could be the problem.

On August 23, 2015 at 11:56pm
Jeremy Tatlock wrote:

I have a quick question.  Can batteries that are connected in series but not connected to a load create a fire hazard or some sort danger?  I know the cells will continue to deteriorate without a charge but I just want to know if there is the potential for a larger problem that I am not seeing?

On August 24, 2015 at 8:36am
Edison wrote:

Why is that a battery should not charge in a dark room?

On October 28, 2015 at 7:06am
zeeshan wrote:

to edison:
never heard of such a thing

to jeremy:
no particular danger other than the series connected batteries could have a very large added up voltage

to jessa:
modern laptops are equiped with charge controlled circuits so no problem

to ish:
same for all lithium ion batteries

On December 25, 2015 at 11:35pm
Jeffrey weaver wrote:

My phonez battery is shot (as in very slow charge and fast dieng) I have a HTC one m7, i tripled the damage yestarday by my using a faulty wire it was rapidly charging then not, charging then not. Ever since this catastrophe my phone no loner charges fast with my other chargers. What do I do to fix the battery?

On March 2, 2016 at 4:48am
Mohammad Khaled wrote:

Can I use my laptop while charging?
or is it better to shut it down until it finishes charging then use it?!

On March 4, 2016 at 10:12am
SanDesh wrote:

I have some questions although i got some of my answers..
1.Which one’s better??
If i charge my DELL laptop to 100% and then plug out and work till 20% OR I keep on charging it even after 100% and use it..
2.does full charging the battery cause damage to the battery??
3.Is it good to charge my battery when it’s 20% or 50%??
Thanks in advance…

On March 29, 2016 at 7:46pm
James Crieta wrote:

Hi there. I have an ASUS K455L laptop which I have bought last December. It has a built-in battery. I am an active gamer, so with that, I would like to ask (I HOPE I GET ANSWERS) if should I leave my laptop plugged in when playing games? What I currently do is that I charge my laptop up to 80% (sometimes full) and then unplug it. Then when it reaches < 30%, I plug it once again and wait for it to charge back to 80%. Am I doing it right?

Please I hope I get replies to my question.

On June 23, 2016 at 2:59pm
Katie Sears wrote:

We recently took our Asus laptop with us to my brother-in-law’s house in Iowa. We live in Nebraska. One thing my husband and I both noticed is that even though we were using it without the cord, the screen did not dim like it does when it’s not plugged at home, AND the battery lasted for hours. The low battery light comes on after only a few minutes when we use it just off the battery at home. Because of these two things, we rarely use it at home without plugging it in. As soon as we unplug it, the screen dims. Just curious as to why the battery lasted so long at our brother-in-law’s and why the screen stayed bright without it being plugged in there. Any ideas on this?

On July 4, 2016 at 8:13pm
jisan wrote:

I bought a new Asus 202s notebook, can I use it connected to AC even it’s battery is full charged? Can I use my notebook by connecting it always in AC even it is charging? will it be bad effective if I use my notebook keeping it connected in AC always,, Thnx in Advance.

On July 10, 2016 at 11:11am
samshina224 wrote:

i have acer pc that not more than 30 minuets how i control it

On July 18, 2016 at 7:55pm
Bamboo wrote:

Just bought a new replacement battery for hp laptop. Lithium. Anyone know the protocol for charging replacement batteries?
I didn’t do to well on the original battery.


On August 3, 2016 at 3:58am
Baoran wrote:

They say that it is better not to use the battery while it is recharging. How much it helps with how many charge cycles battery lasts if you always turn off your mobile phone while it is recharging?

On August 22, 2016 at 11:37pm
Anne wrote:

Hi there,

After various trial, Surprisingly, the power bank reached full charge (i.e. the LED light turned white) only twice. In the two times it was not connected directly to power outlet but rather through USB of a TV or CPU of desktop PC.

These two options are not easily available on a trip or hotels and in so many countries the power outlet is 110.

So please advise what can I do taking into consideration that my power bank is newly bought.

On September 9, 2016 at 3:00am
DenisWH wrote:

I am fitting an LED module to an outside burglar alarm to give an operating display usually running on a 9v alkaline PP9. I want to power from a 9v DC mains adapter but would like to strap a 9v rechargeble across it to cover the event of mains failure. The adapter has settings and I can set it almost on 9v but for a few mV. Would it be ok to leave this arrangement in place?

On September 13, 2016 at 6:50pm
Saad Ali wrote:

I have a question. will a cheap charging pack for iphone 5 effect the battery life like “pocket juice”. I searched every where but i did’nt find the answer thanks.

On October 16, 2016 at 6:59am
ik wrote:

Is it possible to used UPS to charge or extent time for 2hr, for my rechargeable Fan when light goes off at night

On December 3, 2016 at 4:12pm
Paul Jones wrote:

I have a KAITOL solar radio. It has a Lithium battery. It didn’t supply an AC charger and I am hesitant to use an incorrect one. The Kaito company is absolutely useless to respond to my inquiries.
Is it possible to get some guidance PLEASE

On February 22, 2017 at 3:28am
Edwin Eche wrote:

Can Absolyte batteries be constantly charge with rectifier? I used absolyte batteries which is constantly charge with rectifier and does not last for ten hours after full charge what is the causes?

On March 24, 2017 at 11:10pm
mdog wrote:

Hey battery dudes and dudettes , if you have a battery operated drill with a 67v LI po battery on a charger, and you switch the device on while charging (drill), does it damage the battery?

On March 31, 2017 at 11:36pm
shaik ziya ur rehman wrote:

Some body says that if your phone shows 100% it means that the battery charges to70% is it true

On April 10, 2017 at 3:02am
manimaran wrote:

what will happen when we connect exide 12v/200Ah lead acid battery and prestolite 12v/ 200Ah lead acid battery in series to achieve 24v to start the diesel engine
(note : incase both having different charging current, electrolyte volume & CCA ?

On June 6, 2017 at 5:05pm
Andrew wrote:

I know fast chargers only recharge batteries to 70%, so my question is this: is it ok to use a fast charger up to 70%, then use a regular charger for the remainder to get the full charge out of the battery, or will I be degrading the life of the battery? Thanks!

On July 27, 2017 at 4:31pm
Yura wrote:

Can I Ieave my computer plugged-in or will it kill the battery?  How often I should let the battery discharge to keep it healthy? Some say it will die in a year if I don’t use it!

For example, this Apple manual doesn’t answer my worries: https://www.apple.com/batteries/why-lithium-ion/ :(
So, I came here and I have read your comments people. I understand that Zeeshan recommends (thank you Zeeshan for your answers…) ... that Zeeshan recommends to keep the battery charged if it’s not a problem and once in a month let it drain to 10 %
Am I correct? smile

On October 20, 2017 at 9:55pm
Rick wrote:

My dell laptop battery has a mind of its own and refuses to accept firmware settings 80 percent of the time.

On November 21, 2017 at 1:52am
dan oshea wrote:

Glorianne and Lynne; re: your enquiry about battery capacity increasing from 900 mAhrs to 1200mAhrs. The relevant number in this case is that both batterries are 3.7 V dc. So it is perfectly safe for you go ahead and use the new battery. You should find that you will get about 30 % longer between charges; all else being equal. The unit mAhrs refers to how long the fully charged battery at 3.7 V dc is able to deliver 900, or 1200 milliamps, so 1.2 Amperes for an hour, before becoming fully discharged. The old one could only average 0.9 Amperes over the hour. It refers to the capability of the battery to deliver power. As long as that power is delivered at the rated voltage of your device; 3.7 V dc in this instance, then it is suitable for use with that device.

On December 9, 2017 at 12:09am
Rick54 wrote:

Could I use a bike powered charger to charge the battery for my e bike it’s not a li ion battery just a regular one. Trying to go cross country on an e bike trying to figure out how to keep charging it.  Would that work does anyone one know an easy way for a lame in to do so?

On December 20, 2017 at 11:04am
Banananutbread wrote:

Can i charge a 9.6v 1309mah lithium ion rc car battery on a fast charger for nimh and nicd batteries? it supports 9.6v 1600mah batteries.

On January 9, 2018 at 12:34am
Bob wrote:

Will a lithium-ion laptop battery discharge if the laptop is shut down and the charger is left plugged into the laptop, but is not plugged into the wall socket power?  That is, can the laptop battery reverse discharge thru an un-powered charger?

On February 15, 2018 at 12:00pm
Akshay Nagar wrote:

I kept my laptop (with battery)plugged in for normally 3-4 hours a day for a month for working on very small task (like reading only in which there was negligible heating in my LapTop ) ,on the wrong advice of my friend.
Can you tell me that how much I had damaged and can I improve it again by keeping it charged between 40%-80%.

On March 31, 2018 at 7:53am
Anita Memezi wrote:

I have a new LG K10 and i dont know how i should charge it, will i damage my battery if i top up power while there is still some

On July 28, 2018 at 6:38am
Wade Bolt wrote:

Have 2 12v batteries on fishing boat. After charging boat will not start. One battery is warm and one is cold.  What battery is not working

On September 11, 2018 at 10:12am
Sid wrote:

I want to ask what will happen if i do not use gel batteries for 6 months without charging them. Does this affect anything with batteries without using them and charging them.

On September 14, 2018 at 12:34pm
John Harvey Harvey wrote:

Thebattery charger for my golf cart no longer works. Do I need to do anything special to dispose of it?

On September 15, 2018 at 9:04am
John Harvey Harvey wrote:

I did not receive any kind of information regarding my question about disposing of a battery charger…..

On September 17, 2018 at 7:54am
John Harvey Harvey wrote:

Nothing in your response have me information about disposing of a battery charger.

On October 28, 2018 at 5:34pm
Martins wrote:

For two years the 4110 mAhr 7.4V pack on a new ASUS notebook was rarely discharged below 92%. Most discharges were less than 2% while transporting it on standby for about 200 occasions. Recently when running it on battery power for 40 minutes, the battery LED began incessantly flashing amber/green. I used the computer daily for another week before detecting additional discharge. I tried running the computer for an additional 3 hours on battery power, reducing the charge to 14%. I have since bypassed the electronics inside the battery and am charging it directly at 0.3A. I had 7.8 V. After 7 hours it was 8.4V. I plan to charge it to the 8.7 Volt limit. Is it bad electronics?

On October 30, 2018 at 10:19am
Steph Wentworth wrote:

Hi. If I have an odd number of AA batteries, can I pair it one that is empty of charge with one of the exact same spec and type that has been fully charged, without damage to either?

On December 16, 2018 at 6:15am
Sylvain Alain wrote:

Hi, I would like to know what’s the difference between an iPhone battery that is not supporting quick charge and a battery from an android phone that is supporting quick charge 3.0 (qualcomm) for example ?

I don’t understand how is possible for a one plus 6T McLaren device to charge from 0% to 50% in 20 minutes. iPhone charger is basically 1a at 5v and for example the McLaren charger is a 5v at 6amp.

I’m pretty sure that the one plus battery may heat up big time because the charger is push really hard and fast energy.

The charger technology in the mobile phone is progressing each year.

On December 19, 2018 at 5:56pm
Ben wrote:

Can I charge d-size nonrechargeable batteries as long as I keep them cold?

On December 22, 2018 at 1:08pm
Charles wrote:


I have a MAHA Powerex 9000 charger and it works great but I find that the batteries are getting really hot when charging 2700Mah > Charge 1300mah
Is putting a small air blower/ fan to shoot on the batteries will be a good practice?

They are now charging and they are being cool while at it. Is this preferred?

On December 24, 2018 at 8:26pm
Manon wrote:

Hi, I’m kind of a tech-idiot so, is using the phone while charging bad, yes or no? And when should I charge until the percentage reaches where?