DIY Laptop Battery Rebuild

by Kevin O'Brien

A day will come when your notebook's rechargeable battery will no longer charge and instead serve better as a paper weight. As you use your battery more often, the battery loses more and more capacity until it finally won’t accept a charge and goes flat. Replacing a battery is easy, but the new battery price could be so steep that it costs more than the notebook is worth. Buying a refurbished battery can drive the price down even lower, but what if you are super cheap? Well, we are going to cover this last option, which means tearing apart your old battery and fixing it yourself.

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Dell E1705 Battery Specs:

• Voltage: 11.1v
• Capacity: 53WHR
• Original Cells: Sony SF US18650BR
• Replacement Cell Specs: LG 1650 mAh li-ion Battery w/ tabs

Teardown Process

Breaking the battery apart was probably the single most painful moment of this entire article. I had no documentation to work with, the plastic halves of the battery were glued together, and all I had was a mini snipper. I first started by peeling off the top sticker exposing the open framework with cells in view. After this I took my little snippers to the plastic, and cut away piece by incredibly small piece till the entire top was removed. I had black plastic bits flying everywhere; I think even into someone’s can of soda. The end result was a brutalized battery case that looks 100 percent safe for future use.

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Once all of the excess plastic was removed, I could get to the cells I would be replacing. All of these were glued in place, so prying them out with a screwdriver was the only option. As I slowly lifted each group form the plastic case without shorting any circuits, I took my clippers to the metal bridges to fully disconnect the batteries. During this time I also made special note of the wire leads off the charging circuit and where they connected for future use.

Finding the Correct Replacement Cells

Who would have thought finding something as simple as US18650BR batteries would be so hard? It actually took two of us about 30 minutes to find a site that sold equivalent batteries. We narrowed in on MegaBatteries.com, as we found it mentioned on some odd website as a place to find batteries. Now the standard name for the battery size we were looking for was 1650, and we picked one at random since they had quite a few options to choose ... and I was too lazy to run the math on the correct cell capacity. With the cell selection locked in I ordered the batteries, and sat patiently until they would arrive.

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Build Day

Once the new batteries arrived at the office, I got to work on prepping the batteries for installation. I verified battery orientation from the pictures of the old assembly, and started to solder together pairs of cells. I used some old wire to bridge together each group on the positive and negative side, and hooked the first battery group to the red power lead. Next step was soldering together the second group, attaching it back of the first group, and soldering both charging leads in place. Last was the third group soldered to the back of the second, and attaching the black lead to the rear of the battery group. The final result doesn’t instill much confidence of a non-firey demise, but it was finished. To add a layer of safety I placed some packing tape over the exposed battery groups, and mashed the "rebuilt" battery into the bottom of the notebook. To the surprise of all those around me, the battery did not ignite into a ball of flames, and actually started charging.

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Performance

The Dell E1705 laptop was not the pinnacle of mobile performance from the start, but with the old battery it was difficult to get more than 25 minutes of life before the notebook shutoff. Anything above that value with the rebuilt battery would be a mild success, so I crossed my fingers and hoped that an hour of smoke inhalation (soldering) wasn’t wasted. The results of the rebuilt battery ended up being roughly 47 minutes of battery life, and a Dell battery warning saying the battery had reached the end of its useful life. While the cells were fresh, the batteries charging circuit hard already reached the point of no return. No matter what we could do, it would never reach the charge levels of its prior brand new state.

Conclusion

With the labor involved in rebuilding the battery, and the $53 spent on parts, the DIY rebuilt Dell battery never got anywhere near the performance of a new battery. Although it was a fun process the money could have been better spent on a professionally refurbished battery or a brand new OEM battery from Dell.com. Even if the rebuilt battery did achieve results similar to those of a brand new module, I don’t think anyone in our office would have trusted that notebook to charge unwatched for any significant period of time. With brand new batteries exploding left and right, do you really trust something you rebuilt yourself?

Pros

• Tons of soldering smoke that freaked out coworkers
• People don’t mess with you after they see this in your hand

Cons

• Bringing this through airport security creates a stressful and unhappy situation

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What a shame that it didn't end up giving you much more battery life. Do you happen to have a multimeter on hand? A fully charged Lithium battery should reach 4.2v's from my experience. But since the battery is 11v's it has to have some sort of regulated circuit. I assume this is also preventing the batteries from fully charging properly. If the batteries are at 4.2v's than you can be sure that they are fully charged and that the batteries are just... crappy batteries with a low mah capacity. If the voltage is lower than this, then it might not be fully charged.

Also, I just noticed the 18650 in the model # on the batteries. 18650 Lithium battery cells are actual a very popular and easy to find size. I have a CREE LED flashlight and a Xeon light that runs off of them or two CR123A Lithium Cells. DealExtreme has them for $4.70 shipped per cell. Or $4.06 shipped if you order in bulk (5 ore more). So 6 x $4.07 = ~$24.

I also have a charger for charging lithium CR123A's and 18650's. When fully charged they are in the 4.17-4.21 range. If they are not, then they are not fully charged. The cells are rated at 3.6 or 3.7v. The reason for this is they quickly decline in voltage from ~4.2 to 3.6 then stay around this range. They can be used till about 2v but this will limit the life of the cells.

Also, I think you put in lower capacity LG cells than the original Sony ones. The LG ones say 1650mah. So 6x1650 = 9.9 ah. 9.9x3.7v = ~36Whr's. The original capacity of the 6 sony cells combined was 53Whr's. So using basic math, this would tell us that the capacity of each sony cell was about 2400mah. 2400mah is just about the highest 18650 cells get too. So that’s encouraging to see that dell is using the highest capacity cell's available.

What was the original battery life like with the Sony Cells?

 

Cool Pros and Cons .

 

"A" for Effort?

 

Nice work, man!
Although, I am hoping that no one from FAA is reading this post otherwise there might be some new rules come out to make sure no one is carrying some explosive self-made "batteries" onto the airplane.

 

• 
  
  LOL
  
  Thanks for the interesting read. I see you can't help disassembling things. Can I make a wish list for the next things you should take apart?

 

LOL at the cons become a a terrorist suspect

 

Wow, maybe Jason should offer a counter review to show he knows what he's doing better than Kevin when it comes to rebuilding batteries

Nice attempt Kevin, it's probably safe to avoid doing this unless you really know what's up.

 

While the difference in battery capacity is true, in a prior review we got close to 2 hours and 41 minuted on the 6 cell battery. On the rebuilt battery we barely broke 47 minutes. The batteries we bought were not 30% of the original capacity

 

Christ, you're not joking about that last pro...

 

I did this once for an Asus M3N battery. It worked fine, the biggest problem was that a lot of the circuits, unless you keep them powered (or so I have heard) while you rip the batteries out, will never report the correct battery info to your computer again. :/

 

LOL, I really don't know anything about rebuilding notebook batteries. All I know is about the lithium cells. But now that I think of it, I just might try doing some sort of a review because my dads xps m1210 battery is dead and he ordered a new 9 cell. His dead one is a 6 cell and right now, it lasts for 20 minutes

My guess is that the regulator on the battery that Kevin opened up was designed for 2400mah batteries, and with him putting 1650's in that might explain why they are not getting charged properly. Perhaps if 2400's were used, the battery would work like new.

 

I just bought a used (but still working) pack for my Inspiron 8600. I also asked myself why it shouldn't be possible to replace those batteries by yourself but found no documentation whatsoever for this, and before I saw those pictures I was scared to open the accu pack.

I think you have some points there, he must have had the wrong type of batteries. There is no reason why good replacement batteries shouldn't perform equally good as the original.

BTW, there are 2600mah batteries by Samsung available at Conrad Electronic in Germany (Ansmann brand). I guess that's the max, but also at a max price (16€ = about 23 USD).

 

To correctly build a battery pack, you'd have to clear the EEPROM through the SMBUS interface using a software.

Also, if you use DealExtreme batteries and the battery burns down your house, who are you going to sue?

 

Well on top of the charging issues, the cost of this rebuilt battery in parts comes close to a professionally rebuilt battery off ebay/etc with warranty

Andrew since he made me do it

 

Good effort, but e1705 batteries can be had for as little as $40 shipped on ebay. A lot practical (safer, no work required, doesn't look ugly, etc...) for everyone.

 

lol haha, thats funny. Man, you are so crazy, is this your punishment for spamming OT with free stuff?

 

I wanna do it! But I am too scared I have a HP/Compaq Presario B3800...for those of you who dont know what that is, I just found out that its also call NX7100 in other parts of the world (never realised it was a business noteobok until today...) Battery life = 40min...used to be 4hrs...6cell 11.1v 4.4Ahr...

Should I do it?

 

Yes, do it right, get help, then sell it to NBR.

PLEASE!!! I want to do this for an old laptop of mine...


Otherwise...

...will it blend?

 

hehehe

One major problem is that I must be able to put it all back together...I spent a fair amount of time going through various airports...

 

Funny pros and cons, but not very safe to DIY. Just best to spend the money and buy a new battery from < insert notebook manufacturer here >.

 

Well not when my battery cost $120

 

I understand, I know they're expensive. But still not worth it. It's not safe. Sounds like it was a fun experiment though.

 

Yeah I'll probably do it when I eventually get round to buying a new notebook...heh

 

Awesome review, very original

 

My Clevo's battery doesn't hold charge at all. Time to get to work, I guess.

*picks up a machete*

 

If anything we prooved this is a bad idea. It's my machine Kevin molested, I'm afraid to even turn the little bugger on any more. I had to today for a few minutes, but shut 'er down before my manhood went up in flames. Kevin has since been banned from touching things on my desk and we're now trying to ensure he's traveling to trade shows as much as possible, less damage can be done that way.

 

I would imagine this could be done much safer, if you just peeled the sticker off and snipped just two of the bits of plastic holding the battery down. then replaced the sticker over the top when done...

just my .02

 

are you sure that's a smart idea? kevin, with exploding batteries representing nbr? though i suppose now we can strong arm companies into getting review units with bomb threats

 

Wow. This give me the urge to tear apart my (perfectly fine) FZ battery...

 

i did this to my dell 6 cel batt following some "instructions" i saw on a youtube video. my batt had gone down to <1 hr so i figured why not.

this guy did something wrong because brandnew the original batt held about 4 hrs undervolted in XP.

"rebuilt" battery holds just shy of 4 hrs in Vista "balanced"

 

Haha. Why not take the battery out before turning it on? At 47 minutes it isn't super-beneficial anymore, anyways. And I wouldn't trust it not to blow up, either.

Yeah, I think I'll spend the money when I need a new battery.

 

I NEED to work at Notebookreview. Now.

I laughed about 4 times. Very entertaining article Kevin.

Funny enough, I had just finished soldiering together some solar panels for use as a battery charging unit! On the same desk I have this MBP running on, actually.

Nothing like a burning hot iron 8 inches from the MBP. I had two fans madly blowing all of the soldiering smoke out the window of my 16th floor dorm room, as a tripped smoke detector in my room would result in a SERIOUS issue with housing personnel.

Too bad the battery in this Mac is only 6 months old...

(Puts small sheet of black paper over battery indicator)
"OH WOW! Looks like it can't hold a charge anymore!"
(Perversely nears MBP with soldiering iron)

I want your job,
and Sincerely,
Burning Apples.

 

Uhhh, ok, well, when you wreck it, can you send me the 18650 cells for my flashlights? Thanks.

 

Wow this make me want to try it it just happen my landlord does rebuild nicad batterys packs so he has all tools to do it just does,nt do lion cause of risk of deaths :> lol

I cound even get table weld nicely

lol do i want to risk kill my self um :? that is the question

 

I enjoyed the article.

I wonder when (if ever) manufacturers will design a notebook which accepts replaceable AA Ni-MH batteries? The first manufacturer to do this would have a competitive advantage over the rest... well, at least among us cheap bastards.

How about a standard form factor for the MB so we can replace the guts when they become obsolete, while we're at it!

 

rofl that thing looks dangerous even though its only a battery pack hehe

 

AA Ni-Mh? You would need a lot of those. The AA Ni-Mh I use (energizers) are only 1.2V. At 4.2V this battery used 6. So, you would need 21 AAs just to get the proper voltage. I don't know about you, but I don't want 21 of those things, considering that they get warm. Not to mention, charging time isn't usually that good on them.

 

Since my M90 battery is dying...
Nah...
I'll just use my M90 without a battery for awhile.

 

This seems to be a great way to blow up your room...

 

Or your house...

 

Nice article on rebuilding battery packs. I used to rebuild my nicad packs for my ham transceivers as they were outrageous for new ones.

I had a Dell C1295 that was on the fritz (1st, 3rd, and 5th lights when pressing the battery button) so I decided to open up the pack. On the C1295 they aren't glued, but you would think so as it is a really tight slip fit with lots of little mating catches.

The long and short of it is that I wouldn't recommend a rebuild on this one unless you have access to a spot welder. There of course is the blinking light circuit board which is connected to another board through a soldered down flat cable. The other board (which connects to the laptop) contains the thermistor. IIRC the thermistor is there to limit charging current so you can fast charge the cells.

I can get replacement battery packs for about $40 so I don't even think this would be cost effective, except for the fun factor.

 

This article is ridiculous. Where are the safety risks and assessment for such a procedure .

I'm sure you have seen Dell laptops that catch fire because of battery problems...

It doesn't work properly anyway .

Just buy a new battery and protect your warranty and your life.

If you have money to buy the laptop you should be able to dish out £50 every few years for a new battery.

Article should be pulled to prevent immature audience from harming themselves and others.

 

Or...maybe you shouldn't take it so seriously

For some people who spends £400 on a budget notebook, are you going to tell them to spend £50+ for another battery?

The article clearly listed the disadvantages, so really its your choice to do it or not, no one is telling you to do open up your old battery and replace the cells are they?

 

Yes but it is potentially misguiding (the title does say DIY battery rebuild). Some people may not see the pros and cons and safety implications.

Even if you spend £400 now, you might need to spend £50 on a new battery in THREE years if it get really bad. That's not too hard?

Although nobody is telling you to do it, this article encourages people to think about it, it tells you that you have an option and supports you if you decide to take that option. This in itself is dangerous - literally.

Please use your £400 CPU less and your brain more. (No offence intended).

 

As a matter of fact I dont own a £400 notebook

 

There's risk with anything, but the consequential loss with battery fire is just too great. You don't necessarily have to get a new one, but it's a good idea to get a used OEM from unlucky mate who broke his laptop and put it on eBay, a brand name generic replacement (such as those sold under Duracell brand) or have it rebuilt by a rebuilder that's been around for a while.

You'd really want to have someone to go after if it burns down your car or house. Using homebrew one, your insurance company might even deny payment.

 

Just because they wrote an article that its possible doesn't mean its encouragement to do this. If you even read the article (just a little of it) the tone is that you shouldn't bother doing this.

 

I think for most modding articles it's general knowledge that you follow them at your own risk. People not comfortable doing that kind of stuff just don't, and the rest of us know better

 

*runs around wildly covered in exploding battery induced flames*

DAMN YOU NOTEBOOKREVIEW!!!


AHHHHHHHHH!!!