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):
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!
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 OEM | 13.8mm |
NewerTech | 14.3mm |
2-Power | 14.6mm |
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!