# How to charge a laptop batt help



## Changchung (Nov 14, 2013)

Hi guys, I have a battery laptop almost new from a bad laptop dell, how can I charge it without the laptop?

I know this option but is so expensive...

http://www.ebay.com/itm/221237555257?redirect=mobile

I will glad with any kind of help...

Thanks


Sent from my phone with camera with flash and internet on it...


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## Nano-Oil.com (Nov 14, 2013)

Changchung said:


> Hi guys, I have a battery laptop almost new from a bad laptop dell, how can I charge it without the laptop?
> 
> I know this option but is so expensive...
> 
> ...



Hello Changchung,

First thing first, have you taken a volt measurement yet, use the 2 most apart slots on the battery, 
this will take you directly to the battery by passing the controller inside.
there is not reason to proceed until you know that answer, then we move on to the next step.


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## Changchung (Nov 14, 2013)

Nano-Oil.com said:


> Hello Changchung,
> 
> First thing first, have you taken a volt measurement yet, use the 2 most apart slots on the battery,
> this will take you directly to the battery by passing the controller inside.
> there is not reason to proceed until you know that answer, then we move on to the next step.



Hi Nano, yes, show 12volts... I was thinking if the other slots are like in the RC batterys to balance the charge...


Sent from my phone with camera with flash and internet on it...


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## Nano-Oil.com (Nov 14, 2013)

Changchung said:


> Hi Nano, yes, show 12volts... I was thinking if the other slots are like in the RC batterys to balance the charge...
> 
> t...



and what is the voltage written on the battery: 
10.8 V or 11.1 V this would be considered a 3 cell series battery 
or 
14.4 V or 14.8 V this one would be a 4 cell series battery

a 3 or 4 cell battery can sometimes be of the same length, 
they just put dummies in the 3 cell cases
so it is important to know what is written on the battery 
ADDED so to know what state the batteries are at the moment.

most common is series parallel containing 6 or 8 cells 
sometimes


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## ChrisGarrett (Nov 14, 2013)

Crack it open and scavenge the cells, since it's 'new.'

Chris


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## Nano-Oil.com (Nov 14, 2013)

ChrisGarrett said:


> Crack it open and scavenge the cells, since it's 'new.'
> 
> Chris


Hello Chris,

I know that, this is what I would do specially if the pack is hosting an extended type say 3300mah per cell 
but Changchung has not told us what his plans are or reasons for wanting to charge it. 
Maybe he just has a battery feddish, just like I have. LOL


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## Changchung (Nov 14, 2013)

Nano-Oil.com said:


> and what is the voltage written on the battery:
> 10.8 V or 11.1 V this would be considered a 3 cell series battery
> or
> 14.4 V or 14.8 V this one would be a 4 cell series battery
> ...



Hi again, sorry for the delay, the batt say 11.1 7200mah it is heavy, must have 8 cells and it is new, had a bar led that show the state of the pack and all leds still go on when you press the button



ChrisGarrett said:


> Crack it open and scavenge the cells, since it's 'new.'
> 
> Chris



I want to try to use it for some 12volts device first



Nano-Oil.com said:


> Hello Chris,
> 
> I know that, this is what I would do specially if the pack is hosting an extended type say 3300mah per cell
> but Changchung has not told us what his plans are or reasons for wanting to charge it.
> Maybe he just has a battery feddish, just like I have. LOL



I dont want to use before I know if I can charge it... I will like to use it for some 12volts device...


Sent from my phone with camera with flash and internet on it...


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## Gauss163 (Nov 14, 2013)

Nano-Oil.com said:


> Hello Changchung,
> 
> First thing first, have you taken a volt measurement yet, use the 2 most apart slots on the battery.



It is not that simple for Dell batteries. They will not enable output unless the SYSTEM PRESENT pin is grounded. This is the fourth pin from the left, looking at the connector on the battery. See the photos below. The 2 leftmost pins are negative, and the 2 rightmost positive. The first photo shows a connector that was harvested from an XPS M1330 USB battery Board 48.4C302.031 (about $4 on eBay). The second photo shows a universal connector configured for a Dell battery (from a Poloso universal laptop battery tester). The 2 additional wires on the 2nd photo are for Smart Battery communication over its SMBus.

I employ the first board so that I can use my Dell batteries as universal 12V power supplies. This is very handy. For example, I can use my spare laptop batteries as backup (ups) power for my 12V cable modem. Since the modem runs fine at the 9V-12.6V output of 3S Li-ion. no step-up conversion is needed (so no consequent power loss due to such). Indeed, my 90Wh battery powers the modem's 300mA load for over 27 hours, much longer than common alternative sources, e.g. AT&T's Belkin modem ups backup BU3DC001 yields only 15 hours, but it is 13 times the volume, and 7 times the weight of the Dell battery (the Belkin UPS contains a 12V 7Ah SLA battery).

To charge the battery through the dell pinout requires either the laptop (often the motherboard alone suffices, which is cheap for older models) or some other universal charger that can communicate with smart batteries (e.g. here is one for < $5). Smart batteries will not enable charging without proper commands issued over the SMBus (see the Smart Battery specs). Alternatively, you could open up the pack and charge it with a hobby/RC charger (I'm not sure just how much this may confuse the BMS).


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## Changchung (Nov 14, 2013)

Hi Gaus, I try the batt already with some load and the battery had output, so, I was thinking in do that, open it and charger with a hobby charger. Or can I try your method? Mine is not a new model.


Sent from my phone with camera with flash and internet on it...


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## Gauss163 (Nov 14, 2013)

I've never encountered a _Dell _battery that enables output without shorting pin 4, as I described above. Perhaps you have a very old battery that did not implement this convention? Or perhaps it is a clone, not genuine Dell? What is the model number? Or, better, post a photo of the label on the battery, so we can see all the specs.


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## Changchung (Nov 14, 2013)

I should post pics in the first thread...


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## Gauss163 (Nov 15, 2013)

*Harvesting clone batteries is not worth the risks*

Examining the battery label, notice that it says "Replace ...", and, further, the label does not contain a Dell logo. This is a typical label for a clone (aftermarket) battery. While genuine Dell batteries only contain cells from reputable manufacturers, most (all?) clones contain cheap Chinese cells, often of dubious quality. In particular, they may be much less safe. For example, one of the biggest safety problems is caused by impurities introduced during manufacturing. These can later lead to internal shorts which may cause failure leading to venting of toxic fumes or, worse, explosion. The risk of such defects is much higher with cells manufactured by fly-by-night Chinese manufacturers. As such, generally I do no advise harvesting cells from clone batteries. Always keep in mind the immense amount of energy stored in such a battery pack - more combustion energy than a hand grenade! Better safe than sorry.


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## Changchung (Nov 15, 2013)

Thanks Gauss for your sugestions, I will wait for some extra info about how charging it, if not I will open it and chargering with a hobby charger...


Sent from my phone with camera with flash and internet on it...


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## Gauss163 (Nov 15, 2013)

As mentioned, this is likely a pack of low-quality Chinese cells. Further, it is likely quite old, since the Dell D820 goes back to 2006. So not only does it pose higher safety risks, but the odds of salvaging good cells are slim. My recommendation is to seek a newer, higher quality pack to harvest or repurpose.


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## Nano-Oil.com (Nov 15, 2013)

Changchung said:


> Hi again, sorry for the delay, the batt say 11.1 7200mah it is heavy, must have 8 cells and it is new, had a bar led that show the state of the pack and all leds still go on when you press the button
> 
> 
> 
> ...



it cannot be 8 cell with 11.1 volts it has 9 cells 7200/ 3 = 2400 mah each cells


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## Gauss163 (Nov 15, 2013)

*Dell self-test: don't confuse charge level with health (capacity)*



Changchung said:


> ... it is new, had a bar led that show the state of the pack and all leds still go on when you press the button



That self-test does not imply that the battery is new. Rather, it implies only that the battery is charged to approximately 80-100% of its _current _capacity. For a highly worn battery, the current capacity might be much less than the original (design) capacity. To infer some information about the current capacity you need to perform what Dell calls a_ health test. _To do so, press _and hold-pressed _the self-test button for at least 6 seconds. During the first 3 seconds the number of LEDs that light indicate the current charge level (20% for each LED). After 3 seconds the lights will turn off then turn on again to display the health. According to Dell "if no lights appear, the battery is in good condition and approximately more than 80% of its original charge capacity remains. Each light represents incremental degradation. If five lights appear, approximately less than 60% of the charge capacity remains, and you should consider replacing the battery". 

Note that if no lights come on in the first 3 seconds then the battery may be drained so low that it does not have enough power to run the self-test. In this case no lights come on in the health test either, but this does not mean it is in best possible health. Rather, it simply means that the test did not run for lack of power to do so. Hence if no lights come on then the self-test is inconclusive.

This might not apply to your battery given that it is a clone. Some of them do not implement the health test, or do so very poorly.

Beware when buying batteries on eBay that many sellers (both individuals and companies) frequently confuse the charge test (first half) with the health test (second half). As a result many batteries are mistakenly listed as new or full-capacity simply because they are fully-charged (to _current _capacity, however low that might be).


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## Nano-Oil.com (Nov 16, 2013)

Gauss163 said:


> As mentioned, this is likely a pack of low-quality Chinese cells. Further, it is likely quite old, since the Dell D820 goes back to 2006. So not only does it pose higher safety risks, but the odds of salvaging good cells are slim. My recommendation is to seek a newer, higher quality pack to harvest or repurpose.


a very harvest-able battery is from IBM ThinkPads inside: Sanyos green tops 3.7v 2400 mah, I made my bicycle battery out of them, of course charging could be a problem to some, I use a B8 R/C charger for that and wish I could charge 9 cell but I cannot at this time so I run my controller at 33 volt but I get upwards of 35 miles per charge + a very responsive motor action with none of the meter low charge LEDs going on even on my way back, such lights were going on just about 15 minutes after taking off on my native Lead Acid that came with the bike, PB does not like to release its energy too fast and should never be used for constant high load devices. a series of super capacitors across these types of batteries are a God sent, put them as close to your batteries possible and create yourself a switch to turn them off when not in use, they could discharge your battery over time. 
if anyone knows of a good Lithium Ion charger say up to 48 volts please let me know.


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