Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
In case anyone's interested, I thought I'd provide an update on my quest to find a decent aftermarket 17" MBP battery.

Duracell Direct sent me a replacement 2-Power battery a couple of weeks ago, and this one has been functioning better than the first (both of which were manufactured August 2024). With this battery I can get 4h 47m of unthrottled performance using the test described in my previous post, which sounds good relative to the others… but the test has been designed to produce about 5h 15m of unthrottled performance on a new Apple OEM battery, so 10% less with a battery that supposedly has a higher design capacity than the OEM (8800mAh vs 8450mAh) is a bit underwhelming. Additionally, I can see that each complete charge cycle is knocking several minutes off the (unthrottled) runtime of the battery.

Nonetheless, as Duracell Direct's support has been pretty good (e.g. one thing I appreciated was that they sent me the replacement battery before asking me to return the faulty first one), I was considering just living with the battery, monitoring its performance, then claiming a warranty replacement if it deteriorated too quickly. But I found another issue upon which all the shell scripting and fastidious measurement-taking etc. had absolutely no bearing:

The battery doesn't fit properly.

Because I'd been doing lots of swapping of batteries and other components recently, I'd been using the MBP without the metal base panel screwed on. When I wanted to fix the panel on properly last week, I realised that it wouldn't fit properly without forcing: the tabs on the panel wouldn't engage with the plastic receptacles in the chassis, and screwing the base panel into the chassis resulted in it looking like it was bulging a bit round the edges. One of the reasons I wanted to move on from my previous NewerTech battery was because it was a bit too chunky for the laptop, and this 2-Power one was surprisingly (slightly) worse.

The odd thing is that the 2P battery uses exactly the same plastic housing as the NT one. I don't think the 2P one has swollen cells; upon closer inspection both NT and 2P have a slight gradient in the top surface of the battery near the plastic pull-tab, but the gradient of the 2P battery is slightly more pronounced, probably just due to inconsistent manufacturing. My callipers give the following thicknesses at their maximum points (exc. pull-tab):

Apple OEM13.8mm
NewerTech14.3mm
2-Power14.6mm

So I've requested a RMA for the 2-Power battery and, following a suggestion earlier in this thread and a bit of my own research, found what appears to be the final BTI battery for my MBP in stock in the UK. Concerns about the battery's shelf age aside, I'm fairly optimistic about the BTI one: they seem to have a good reputation, and I think the ‘finished product formula’ for want of a better description is going to be different to NT/2P too because scrutinising product imagery suggests the plastic housing is subtly different, as is the rated capacity (8676mAh). I'll report back once I've received and tested it!
 
Watching with interest.

My Late-2011 13" MBP has served me very well, and now has a sort of sentimental value attached to it. I'm tossing up whether I sink the money into another replacement battery (it had a "genuine" one in 2018, that came to me free through a friend in the IT field, which is at about 55% health), remove the battery altogether and make use of the "NoBatteryNoProblem" kext or just find a newer iMac/Mac Mini.

The current battery doesn't appear swollen, but the bottom case has never fit quite right (it's getting worse) since I installed it and the trackpad plays funny buggers (which has been a problem since the machine was about a year old, I might add...). I've wondered whether years and years in my backpack might've buckled the chassis ever so slightly that the battery just doesn't sit right relative to the wear and tear inflicted on the machine?
 
Man, that battery sounds like it's swelling even if it doesn't seem to be, from your case bulging description. You might want to pull it now rather than take a chance burning your house down. Swelling batteries don't get any better. I'm sure your house is worth more than the $75 battery, or if it's not worth it recycle the laptop and move on. I NEVER use a "new to me" laptop without first opening the case and checking out the condition of the battery. If it doesn't look perfect, it comes out and I either buy another one or decide it's not worth it and take the laptop to a good local recycler (reseller) where someone else might want to spend the money on it.

Good luck!

:)
 
Just ordered a new battery from OWC (NewerTech brand) for my 2008 White MacBook as it's all that the machine needs...it's in pristine condition. I've had such good luck with batteries from OWC that I see no reason to go anywhere else. Should be here soon!

:)
 
Watching with interest.

My Late-2011 13" MBP has served me very well, and now has a sort of sentimental value attached to it. I'm tossing up whether I sink the money into another replacement battery (it had a "genuine" one in 2018, that came to me free through a friend in the IT field, which is at about 55% health), remove the battery altogether and make use of the "NoBatteryNoProblem" kext or just find a newer iMac/Mac Mini.

The current battery doesn't appear swollen, but the bottom case has never fit quite right (it's getting worse) since I installed it and the trackpad plays funny buggers (which has been a problem since the machine was about a year old, I might add...). I've wondered whether years and years in my backpack might've buckled the chassis ever so slightly that the battery just doesn't sit right relative to the wear and tear inflicted on the machine?
It's very tough to find a battery for that machine that is in good condition and doesn't have many load cycles. They are out there! I just sold my 2012 13" MBP which I used as a media server. It was plugged in full time and never powered off for ten+ years. The battery had 42 load cycles and 95% battery health. I was a bit sad to let it go but I replaced it with a 2014 Mac Mini which is more suitable because there is no battery to worry about. That being said, the 2012 Mac mini has some models with quad core i7 processors - the same as in the 2012 15" MacBook Pro models. Much faster than the 2014 Mac mini. The 2012 Mac mini with the quad core i7 can be had for less than $100 on eBay.

I also have a 2012 15" MBP but the battery in that has 136 load cycles! 😛😂

If I wear going to buy a replacement battery, I would find a cheap one on Amazon that has good reviews. It's not worth sinking money into a machine of that vintage because they can often be found for under $100!
 
Last edited:
Right, here's the next update in my quest to find a decent 17-inch MacBook Pro battery.

I received my order of a BTI battery a few days ago and… it's swollen. Not terribly (i.e. it doesn't yet look like a pillow), but on the underside it's possible to see with the naked eye that what should be straight pieces of plastic are now bowing slightly. Which is annoying, because this was the final BTI battery of this model available anywhere in the UK as far as I can tell, so I'm not sure how easy it's going to be to get a replacement.

However, as I had this rare piece of vintage technology in my hands I decided to play with fire (no, not literally!) and do some testing with it anyway – keeping an eye on it frequently, feeling the laptop casing's temperature, so I could switch everything off at the first sign of trouble. Part of my logic here was that BTI, being a big brand that according to another poster in here is sold in well known retail stores in the US, would hopefully have built all the necessary safety features in to the battery. (I wouldn't have done this with a cheap Amazon no-name.)

So, some observations…

Manufacturing date: March 2023. Ouch, no wonder it's got problems.

Design capacity: On all the websites I've looked at, even BTI's own, the battery is advertised as having a design capacity of 8676mAh. However, the Mac reports that it's actually 8350mAh. I'm not too bothered by this because it's close enough to the OEM design capacity of 8450mAh, but it's odd nonetheless.

Controller: SMP, and it seems to be fairly good. During the very first discharge cycle the maximum capacity was reported as 8415mAh, but during the second discharge cycle this had adjusted down to 7657mAh, which means the controller had actually taken readings from the battery and adjusted the reported capacity accordingly. This contrasts with the controller in the NewerTech and 2-Power batteries, whose max capacity readings remain too static (too ‘perfect’) to be genuine measurements. The SMP controller also does a comparatively good job of reporting the % remaining considering that the battery has a defect; it drops like a cliff from 28% to 14% but then recovers itself, whereas all the other batteries accelerate from about >30% right down to 7%. Having said all this though, the controller is still not equal in quality to Apple OEM, which measures the max capacity about every half an hour during discharge.

Runtime: After two calibration cycles I get 4h 52m of unthrottled performance using my shell script. Considering that's about the same as a 2-Power battery manufactured 17 months later than this BTI one, and that this BTI one is clearly faulty, I'm quite impressed – a quick bit of maths using the max capacity figures indicates that if this battery were fully functioning it would actually offer the same life as a new Apple OEM battery.

Heat: This isn't something I'd normally look out for, but I thought it worthwhile to mention that despite the swelling, the battery temperature was never more than pleasantly warm.

Plastic casing: I was right and there are subtle difference in the moulding compared to NewerTech and 2-Power. It's difficult to get a definitive measurement of the battery's thickness because of the swelling, but I think it's 14.3mm, which is thicker than OEM but would be just acceptable going from my experience of the other batteries.

So overall, I think that if this battery weren't faulty, it would be the best one yet. On that basis I am going to try to obtain a replacement, though if I can't get one I'll have to find a plan B (or C or D or whatever we're on now).

Edit to add: I'm definitely not going to use the swollen battery any more. It was just some limited testing I did with it.
 
Last edited:
Never use a swollen battery, that's not a good idea.

Apple is certainly a brand name and builds all of the safeties in their batteries and theirs swell up like crazy all the time.

Just buy a NewerTech from OWC and if the "one" that shows up has any issues return it under warranty for another brand new one under warranty. Their batteries are really top of the line, in spite of anyones "one off" issue they mights have had.

Everything else is just splitting hairs and dangerous.

:(
 
In the case of the 2011 MacBook Pro 17" though, NewerTech batteries definitely aren't top of the line. When I received the battery it didn't work as well as I would have expected, but it also didn't show any obvious signs of failure that would have made it eligible for warranty replacement. Additionally, the controller in the battery is clearly not very good, and the battery is physically bigger than it should really be. And, in the UK at least, it was pretty expensive too.

Perhaps their batteries for other laptop models are better, but I'm unimpressed by the one I used.

As someone who handles old Macs on a frequent basis, this whole exercise for me isn't about choosing the most convenient option right now, but about looking beyond the marketing to find the most OEM-like replacement battery that I can. I (and perhaps others) can then use this knowledge to source better batteries for ourselves in the future!
 
A battery I ordered from a local outfit describes itself in CoconutBattery has having been manufactured by "TOP"... Incredibly reassuring (not). Two earlier posters in this thread appeared to have the same type of battery in their machine - wonder how they're going?

When installed, the functionality of the trackpad returning with everything screwed down nice and tight suggests the old battery was never quite right over the 7yrs I was using it(!), and nor was the OEM battery for most of the 7yrs it was in the machine.

That said, I'm still not entirely convinced the battery is a quality item and will probably dispense with it.
 
It's been a while since I last posted an update to this thread!

As mentioned in my previous post, my newly ordered BTI battery had obvious swelling so I had to enquire about a replacement. I found an RMA form on BTI's US site, and after filling that in they redirected me to an e-mail address run by BTI Europe (who don't appear to actually have a distinct web presence), and they arranged for a replacement battery to be shipped over from the US in their weekly batch and then sent onwards to me. What with customs delays etc. this took some time, but when it arrived I excitedly opened the package to find that…

…it was also swollen. In fact, they were clearly from the same batch because the original BTI battery had a serial number of **************32 and this one was exactly the same but 24 on the end instead.

So I wrote back to BTI and to their credit they were proactive: they asked me to send photos, and following this they pulled all the batteries from that batch and assured me my next replacement would be from a newer batch; they also physically checked and briefly tested the battery before sending it to me to make sure I wouldn't get a lemon.

That all took a little while to process of course, but eventually the day came when it was popped through my letterbox, so I excitedly opened the package to find that…

…hmm. It looks kind of different. Closer (and not-so-close) inspection revealed all manner of differences, which clearly indicated the battery had been produced by a different manufacturer. Some of things I noticed were:
  • The plastic housing was of the bulkier style as used by NewerTech;
  • The battery creaked and flexed disconcertingly;
  • The plastic pull-tab was loose;
  • The warning sticker about removing the battery was stuck in the wrong place, such that it would stick to a RAM module if I didn't unstick it;
  • There was no serial number label on the battery;
  • A label had been peeled off the battery's box, and a small BTI label had been stuck on top of another label.
So it looked pretty likely that it was one BTI had bought and just rebadged rather than had manufactured to their usual spec.

Nonetheless, I installed it in my MBP and gave it a whirl. The discharge performance was actually the best yet, giving me unthrottled performance for about 5h 15m, but there were still some issues: the battery would drop very quickly from approx. 30% to 20%, and the laptop would lose power (so much so that even the clock would reset) with several percent supposedly still remaining.

The oddest thing though was that despite having ‘10.95V ⎓ 95Wh’ printed on the battery, the design capacity reported by the laptop was only 8000mAh – so something clearly didn't add up.

So anyway, I toyed with the idea of keeping the battery but I felt annoyed that I'd paid a relatively premium price for basically an Amazon/AliExpress-level specimen. So, citing the fact the the battery's design capacity was less than advertised, I requested a refund from my place of purchase, and I'm therefore now in the process of returning everything.

I'm not sure where I'll source one from next. Possibly LMP; their batteries aren't sold in the UK but I've found one or two European sites who look like they might be able to send one here. I'll post back when I have some news!
 
It's been a while since I last posted an update to this thread!

As mentioned in my previous post, my newly ordered BTI battery had obvious swelling so I had to enquire about a replacement. I found an RMA form on BTI's US site, and after filling that in they redirected me to an e-mail address run by BTI Europe (who don't appear to actually have a distinct web presence), and they arranged for a replacement battery to be shipped over from the US in their weekly batch and then sent onwards to me. What with customs delays etc. this took some time, but when it arrived I excitedly opened the package to find that…

…it was also swollen. In fact, they were clearly from the same batch because the original BTI battery had a serial number of **************32 and this one was exactly the same but 24 on the end instead.

So I wrote back to BTI and to their credit they were proactive: they asked me to send photos, and following this they pulled all the batteries from that batch and assured me my next replacement would be from a newer batch; they also physically checked and briefly tested the battery before sending it to me to make sure I wouldn't get a lemon.

That all took a little while to process of course, but eventually the day came when it was popped through my letterbox, so I excitedly opened the package to find that…

…hmm. It looks kind of different. Closer (and not-so-close) inspection revealed all manner of differences, which clearly indicated the battery had been produced by a different manufacturer. Some of things I noticed were:
  • The plastic housing was of the bulkier style as used by NewerTech;
  • The battery creaked and flexed disconcertingly;
  • The plastic pull-tab was loose;
  • The warning sticker about removing the battery was stuck in the wrong place, such that it would stick to a RAM module if I didn't unstick it;
  • There was no serial number label on the battery;
  • A label had been peeled off the battery's box, and a small BTI label had been stuck on top of another label.
So it looked pretty likely that it was one BTI had bought and just rebadged rather than had manufactured to their usual spec.

Nonetheless, I installed it in my MBP and gave it a whirl. The discharge performance was actually the best yet, giving me unthrottled performance for about 5h 15m, but there were still some issues: the battery would drop very quickly from approx. 30% to 20%, and the laptop would lose power (so much so that even the clock would reset) with several percent supposedly still remaining.

The oddest thing though was that despite having ‘10.95V ⎓ 95Wh’ printed on the battery, the design capacity reported by the laptop was only 8000mAh – so something clearly didn't add up.

So anyway, I toyed with the idea of keeping the battery but I felt annoyed that I'd paid a relatively premium price for basically an Amazon/AliExpress-level specimen. So, citing the fact the the battery's design capacity was less than advertised, I requested a refund from my place of purchase, and I'm therefore now in the process of returning everything.

I'm not sure where I'll source one from next. Possibly LMP; their batteries aren't sold in the UK but I've found one or two European sites who look like they might be able to send one here. I'll post back when I have some news!

This is why I like letting a shop take care of it. It's an extra $50 for the service but they deal with these kinds of headaches.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.