Just rebuilt my laptop battery!!!

[Cyrix_2k]

I can't believe this worked... I recieved a Compaq Armada M300 in exchange for an old Netgear Wifi card i had. The previous owner bought three of these laptops and thought this one had a dead screen. I got it home, found a suitable power supply (the one from my dad's HP laptop) and it powered right up! PIII 600mhz, 320mb RAM, 12 gb HDD, expansion unit with a DVD drive and floppy. It's pretty nice. However, the battery was 100% shot - it wouldn't even start to charge. Well, I had some known working Micron Trek II batteries, so I pulled one apart to discover 9 cells of the same type that were in the M300 battery. An hour later, I had the working cells in the M300 battery, but trying to get the battery back together was an exercise in futility - so I taped it together with postal tape. It's working great right now with windows indicating a run time a bit over an hour. Hopefully it turns out to be longer, but considering I used old cells, I think this counts as a success story. I may pick up some new cells at a later point.

 

[Cyrix_2k]

ended up at 1:01 of run time exactly. I might modify it to use another 4 cells so I can hit 2 hours of run time. Looks like I'll also be buying an extended battery on eBay for it so I can hit between 4 and 5 hours of run time. I love this laptop - .9" thick and 3.4lbs, it's just awesome for college where all I do is type papers and cruise the web.

 

[ozzlo]

sweet, any pics?


I've not had a battery die on me yet but I know who to turn to if one should ever...

 

[Skeith]

Thats pretty sweet. I rebuilt a battery for my old 386 laptop.

Youre lucky. the only laptop I ever got for free was a 386 25Mhz with installed MCU and 8MB ram. It had a 80MB hdd that I replaced with a 128MB compact flash. It gets 2 hours of battery time. DOS and win 3.11 ^_^

I did buy a new one though since I couldent exactly surf the web on it.

 

[Cyrix_2k]

I'll try and get a few pics up when I add the extra 4 cells onto the M300 battery pack. Right now, I just pulled apart my Gateway Solo 1450's NiMH battery pack and discharged it with a light bulb. I've heard this is supposed to help to overcome any memory effect the battery may have. I don't think the batteries are dead because sometimes the laptop will run an hour on battery power while sometimes it won't even last a minute. If this doesn't fix it, I might try and adapt the battery pack to AA's. I know I can fit 8 AAs for a 2500mah capacity, but I think I may be able to fit 16 for 5Ah of capacity; the original battery was only 4Ah! If there's enough room, I'll also add a power jack for other battery options... it should be interesting. The other option is to use 8 AAs, but have them be user replaceable so that alkaline batteries could be used. With 16, space constraints would necessitate they be permanently installed.

 

[Cyrix_2k]

Alright, looks like my NiMH battery is shot. Just got 15 minutes out of it after the full discharge & recharge which is more that normal but still quite bad. The laptop indicates it still has an 80% charge, but it still doesn't work. I'm going to pickup some AA holders from radioshack tomorrow and rebuild this pack. As for tonight, I have two customer PCs to work on and I may add in the 4 additional cells on the M300 pack.

 

[The_Jizzler]

man ive ben wnating to do this for a while. im wondering, do any of your packs have a PCB in the pack? i took apart a old ibm battery and it had a PCB with some microchips and things. i read somewhere that sometimes these are for battery mangement and that they need to have a constant voltage source so they dont lose the programming. im wondering if ill need to keep a certain voltage hooked into it while im removing and replacing the batteries. have you ran into this? any clue what im talking about?

 

[Cyrix_2k]

man ive ben wnating to do this for a while. im wondering, do any of your packs have a PCB in the pack? i took apart a old ibm battery and it had a PCB with some microchips and things. i read somewhere that sometimes these are for battery mangement and that they need to have a constant voltage source so they dont lose the programming. im wondering if ill need to keep a certain voltage hooked into it while im removing and replacing the batteries. have you ran into this? any clue what im talking about?

mine has a PCB. With Li-Ion packs, it keeps them from discharging below their danger threshold. It must use flash memory or something because it remembered all it's information even with no power applied.

I should have pics up in a second. My M300 battery is very ghetto now... I wrapped the whole thing in electrical tape to hold the extra cells together.

 

[Cyrix_2k]

alright pictures are here:

First, the battery pretty much as it was from the factory. I had already replaced the original cells hence the packing tape.


Here it is opened.


Here's the cells I ripped from the Micron Trek II battery. They're Sony 18650's.


Here's the extra cells wired up in parallel to the other four.


smothered in electrical tape:


fitted to the laptop:


powered on:


and it charges!

 

[Skeith]

Carefull those extra cells paralelled dont draw too much current from the laptops charging circuit or burn out the regulation in the circuit in the battery.

 

[ozzlo]

^^^ woulden't the current be limited somewhat by the laptop's power supply max current and overcurrent protection circuits... The amount of current sent to a battery to charge is very well controlled (not just a couple resistors where you drop the resistance and suddenly you double the current)

with the extra batteries he can now burn a cd without needing to be plugged in

well ok you always could but it was never recommended (at least not on my i8600)

 

[The_Jizzler]

sweet!!! that pasck looks just like mine on the inside! now my next question is what can we use a battery replacements? loose li-ion cells are not available to the public. could we substitute li-po's or nimh's? i guess i need to figure out the charge profile of the laptop itself first and see how its charging.

 

[Cyrix_2k]

sweet!!! that pasck looks just like mine on the inside! now my next question is what can we use a battery replacements? loose li-ion cells are not available to the public. could we substitute li-po's or nimh's? i guess i need to figure out the charge profile of the laptop itself first and see how its charging.

you actually can buy new li-ion cells The 18650's are the most common. http://cgi.ebay.com/Lithium-Ion-11-...056QQrdZ1QQcmdZViewItem?hash=item270088686786

there's also internet stores that sell them. I don't know if li-po's will work, but I know NiMH won't.

 

[Cyrix_2k]

^^^ woulden't the current be limited somewhat by the laptop's power supply max current and overcurrent protection circuits... The amount of current sent to a battery to charge is very well controlled (not just a couple resistors where you drop the resistance and suddenly you double the current)

with the extra batteries he can now burn a cd without needing to be plugged in

well ok you always could but it was never recommended (at least not on my i8600)

I'm pretty sure you're correct. I know that the extra cells seem to charge just fine, it just takes longer to charge them.

 

[imposter]

Hey guys i was linked from http://www.ocforums.com/showthread.php?t=501074
i am having a similar problem, that my battery is not receiving a full charge. I have just opened up my battery. I have a samsung ICR18650 batteries inside. Is the 18650 just a set standard? Can i get any 18650 to replace the batteries inside here?

thanks. pictures will be up soon.

 

[therookie]

Finally another one for the record books .. I have a few at home I might try ..

 

[Cyrix_2k]

I'm pretty sure it is. The cells I pulled from the M300 were marked "Sony Energytec STG US18650GR". I replaced them with used cells marked "Sony Energytec STG US18650S" and they work fine. In reality, any 4/3A Li-Ion cell should work as a replacement. 4/3A is the physical size of the cell, Li-Ion is the chemistry and also denotes that the cell is 3.6 or 3.7 volts (depending on your source), and the amp hour rating only matters for run time. You want the highest capacity cells you can find.


As for my Gateway Solo battery pack, I just bought a new one on ebay for $72. My current battery has NiMH cells so I can't replace them with Li-Ion cells due to the differences in the battery controller. However, I'm still working on converting the old NiMH pack to use normal AA batteries. I for 4x1 AA battery holders, but they didn't have any that would work at either of my local stores so the project is on hold until I find suitable battery holders.

 

[Korndog]

you actually can buy new li-ion cells The 18650's are the most common. http://cgi.ebay.com/Lithium-Ion-11-...056QQrdZ1QQcmdZViewItem?hash=item270088686786

there's also internet stores that sell them. I don't know if li-po's will work, but I know NiMH won't.

good god.. were was this ebay seller when i was considering to rebuild my battery??? last time i went shopping around for 12 cells it came out to 60 bucks! so i just ended up getting a new one for 80 off ebay.

 

[BenziT]

Hi,

I have just rebuilt my Compaq M2013 battery.

However, the charging lights stays on for about 5 mins. Thereafter, it starts to blink.

Any idea what is wrong ? There is no charge to the battery at all. Do i have to do anything eles? ie to reset the battery etc ?

I have left it to charge overnight. No charge to the battery at all.

Did you have to rest the PCB ?

If so , how to do it. < 3 volt per battery ?


Many thanks

 

[ozzlo]

did you use the same type of battery technology? did you wire them up in the same way? did you reverse the polarity?