AC Adapters & Batteries

When buying a used laptop, you take a risk on how well the condition of the battery is in. When I buy a laptop without being able to test it, I consider that there is a chance it will need a battery. On laptops that are two years or younger I will presume the battery will be fine. Here are my thoughts.

I’ll buy third party or used batteries for my laptops.

won’t use third party AC adapters for my laptops.

Lithium Polymer (Li-Po) batteries are a lot more likely to expand or blow up after old age.

Linux laptops may run hotter than Windows based machines, battery life is typically less.

Lenovo benefits with stopping the charging threshold with Power Manager installed, which will allow longer life.

I recommend unplugging your laptop overnight, keeping your AC adaptor plugged in can decrease it’s life by constantly overcharging it.


  • Most laptops will take third party batteries.
  • Some laptops are selective about their AC adapters despite being proper wattage
  • Dell has a chip to determine if it allows that charger to work for your laptop.
  • Sometimes they will charge your battery, othertimes they will not.
  • Ancient Dells use 3 pin trapezoid adaptors.


  • Pre 2012 models you can use third party batteries.
  • 2012 & all Ivy Bridge or later laptops will not take a third party battery because of a specialized chip.
  • There are adapters to fit recent ThinkPads if you have a ‘big barrel’ type of charger and don’t want to buy another one.
  • I use a 90W for all my ThinkPads, 65W on intel graphics models,
  • W series use 135W and up, they’ll have a notch on the inside of it as well.
  • Lenovo discontinued Ultrabay batteries with the T430. 🙁
  • New ThinkPads may have two batteries, afaik the internal unit can be replaced.


  • Most take the ‘small barrel’ but wattage varies so make sure your’s is strong enough.
  • G-Series are power hungry and use a special 4 pin adapter, some docks use that type too.
  • Ancient ThinkPads use a 4 pin trapezoid adaptor.
  • Some IBMs use a slightly bigger ‘small barrel’ adaptor.
  • I use IBM chargers on WiFi routers, external hard drives, & other laptops, its design is more common than I expected.


  • Most will take third party batteries.
  • On the consumer laptops, HP makes a lot of different charger ports.
  • Some laptops you can get adaptors to fit on an Elitebook type charger.
  • Non power hungry Elitebooks could use Dell chargers.


  • Third party batteries are popular on older models where the battery is external.
  • Non-rMBPs are replaceable but require a 3 star ‘Y’ screwdriver to remove 3 of the 6 screws that retain them.
  • MacBook Airs can take third party but since its Li-Po I’d go with OEM to play it safe. They are a bit more tedious than MBPs.
  • rMBP and later are glued onto the palmrest frame, they are severly difficult and may break your touchpad, Apple replaces the housing w/ battery.
  • rMBP & later MBAs use MagSafe 2 adapters which are slightly longer than MagSafe 1, there are adapters for them.
  • Apple patented the magnetic adaptor on laptops, the idea was taken from rice cookers, asian companies decided to not patent magnetic adaptors because they agreed it was a wrong thing to do.


  • Fujitsu, Toshiba and Panasonic have some compatibility with each other.
  • Asus, Acer & Samsung have some compatibility with each other.
  • Sony Vaios have the type of AC adapter needed printed on a bottom label.
  • Some third party AC adapters can be trusted like say Anker, but wattage is the main concern on computers.
  • Some laptops can use higher wattage AC adapters, but vice versa may bust your machine.
  • Unless its big and extremely proprietary/uncommon, most OEM AC adapters cost from $12 to $30 new or used.
  • I dislike third party AC adapters because they run hot, and their plugs seem to fault out more often than chewed up OEM units.

When buying a used laptop, some resellers may state ‘battery holds charge but not warrantied/guaranteed’. The excuse is that oftentimes they do not want a return because the laptop only lasts 3 hours instead of 4 hours. Most resellers (me included) will reinstall OS, drivers & software, test it for a few minutes or day and presume they are in working order. Testing out battery life is time consuming. Resellers who sell laptops ‘for parts’ that included batteries just don’t care if it works, and sometimes recycling a battery costs money. Sellers know a battery can add from $10 to $40 on a listing, plus the laptop looks more complete to buyers, which is an incentive to buy that specific one.

Obviously buying an OEM battery is best, new, direct from the manufacturer. Price however is the hindering point for some of us because it can cost the same or more than what we paid for the laptop! Unless ‘Genuine’ isn’t stated on listing, it might be third party, however some sellers state ‘Genuine’ & whatever third party producer of that laptop so they can get SEO hits. You can buy a used OEM battery, but it produces some risk as to how much life the battery holds. Some sellers state how much charge that specific battery holds, others may state the minimum it charges/holds, or even might guarantee it is working.

As I stated earlier, I’ll go with third party if I just need a battery. I will recommend third party unless its a Li-Po (ultrabay, or thin/flat batteries), then I’ll more likely go for an OEM, or even maybe a trusted third party maker. The cons of buying third party is crap build quality, some manufacturers suck, but remember most listings have a 14 day return policy. I like to buy from ebay sellers who have a year warranty or more, then I would feel more ‘safe’ buying from them, these are sellers who most likely specialize in batteries, better than buying from some random dude.

Cons of buying Third Party

  • Batteries may not charge fully e.g. stated as a 44000 mWh, but charges only to 38000 mWh
  • Batteries may run hotter, which will make you uncomfortable, would not recommend in a high heat environment
  • Third party designs may not fit easily on first try, may protrude due to different design
  • They won’t last as long as a genuine used OEM, e.g. worst case scenario OEM for 18 months, 3rd party only for 10 months
  • Laptops can shut down intermittently while on battery, my W700ds would just die sometimes on battery or would be fine for an hour.
  • They could just drain faster than expected.
  • T430 and later fam won’t like em.

Cons of buying OEM

  • Maybe Expensive
  • Buying the wrong battery for your laptop
  • Thought your $70 Ivy Bridge laptop was a steal? Wait til you have to buy a battery for it!
  • ‘New’ batteries that have been in storage from 2+ years could start degrading and won’t charge to their original full capacity design.
  • Sometimes replacing them yourself may be too risky if you don’t know what you’re doing.

One thing I don’t do is recelling batteries. I have some light soldering skills but I am not ready to even start doing that. The ‘best’ way to recell is to use a spot welder, Reasons why I don’t recell is that the batteries have chips which, once they short out, they will refuse to charge your battery! When soldiering batteries, you risk heating them up too much and blowing them up! Another problem with recelling is that you could damage your battery cover when trying to open it. I strongly recommend to just buy a battery than to try recelling on your own. There are a few companies that professionally recell batteries as well, I would go to them if you want to stick to your OEM battery.

Onto AC Adapters! I feel much better about buying OEM Adapters, they are cheap because they pretty much last for a long time, they’ll outlive 2 laptops. Most laptops use 65W to 90W adapters, which I buy for $10 to $17 shipped. Workstations and gaming laptops tend to be pricier, $15 to $35 is typically the price I’d pay for one. Local stores will always mark up power adapters like $50, and junk ones for $20, too much IMO. If you are thinking of becoming a reseller, and want to buy one of those universal adapters with plenty of ports, go for it, but they’ll die out eventually. Remember stick with legitimate AC adapters say ‘Genuine, OEM, or Original’, be weary about ‘for manufacturer, compatible for’ those are knock offs. If it has the OEM label or manufacturer logo its most likely OEM.

“But xsauc, I don’t want to buy a cheap Chinese knockoff, they could just reprinted sticker and housing on top of their crappy adapter.”

And guess what, OEM power supplies are made in China! If you’re so critical about buying a ‘cheap chinese knockoff’ don’t even buy a used computer, buy a $1200+ new computer from Best Buy, pay $70+ for an extended warranty and join a consumer luddite hugbox while you are at it.

Here is a small list of eBay sellers who sell OEM parts. Note some of these companies do not have 100% feedback, however seeing how many transactions they’ve had & the variety of items/prices it is expected.

Useful Gadget





I’ve bought from in the past