battery Archives - Neil Turner's Blog

Midlife iPhone overhaul

May 9, 2026 by Neil Turner

A photo of an iPhone 13 Mini with iOS 15 showing the home screen

Last month marked three years since I bought my iPhone 13 Mini. Unfortunately, it was starting to show its age a little – the battery was not holding charge very well, and the charger port was being awkward, which exacerbated the charging issue.

I quite like the size of the iPhone 13 Mini, and I’m disappointed that Apple has stopped making iPhones this small. As I write this, the smallest iPhone is the iPhone 17E, which is 15mm taller and 7mm wider, as well as weighing 30 grams more. And compared to the iPhone 17 Pro Max, my phone is 2/3rds of the weight, 30mm shorter and 12mm narrower. I resisted moving from the iPhone 5/5S form factor to the iPhone 6/7/8 partly because I felt that was too big – the iPhone 13 Mini has turned out to be an almost perfect size.

So, I have a good reason for sticking with my current iPhone. Plus, sorting out the issues with my phone would prove to be much cheaper than buying a new one.

New iPhone battery

I had previously had the battery on my iPhone 8 replaced, which helped it last for five years. So, doing the same with my current phone made sense. I was able to get a local phone repair shop to do the job in about half an hour, so that I didn’t have to be without my phone for too long. The ‘new’ battery isn’t actually brand new; it’s been recovered from another iPhone 13 Mini that had been disassembled. As such, it didn’t have its full 100% battery capacity as new from the factory. Instead, it offered 94%, which is better than the 80% that my current battery offered. 80% doesn’t sound too bad, but I was having to charge it multiple times per day – especially when we were in London. At 94%, it can do some whole days without needing a top-up charge.

As the new battery is a genuine Apple battery, the phone doesn’t complain about it. Indeed, the engineer who fitted the new battery walked me through how newer iPhones are able to authenticate genuine Apple batteries fitted outside of the factory. Once the new battery is fitted, it reboots into a cut-down version of iOS where it authenticates over Wi-Fi, and then reboots again when done.

Cleaning the charger port

The phone repair shop also cleaned out the charger port for me. I’ve tried blasting it with a can of compressed air, which helped, but it could still be awkward with some cables. Instead, the shop used tweezers to pull out stray dust that was insulating the contacts in the charger port. It now charges much better.

I wouldn’t go far as to say that my iPhone is like new again. Arguably it now acts like a one year old phone, rather than a three year old phone, but that’s a big improvement. It would be great to get this one to five years old, like its predecessor, before needing replacement. By then, maybe Apple will have started offering a smaller form factor iPhone again?

As for the cost? For the new battery, installation and charger port cleaning, I paid £60 at the local repair shop. Had I opted for a third-party, non-genuine battery, it would have been cheaper. By contrast, Apple charges £85, and I would have also had to factor in getting to the nearest Apple Store in Leeds. £60 for what I hope will be another two years of use isn’t bad.

When you should (and shouldn’t) charge your electric car to 100%

October 8, 2025 by Neil Turner

Something to bear in mind about electric cars is that their batteries will degrade slightly over time. As the batteries age, the maximum range obtainable from the batteries on a full charge will go down. How quickly this happens will depend on how you use and how you charge your car, and in this blog post, I’m going to talk about the impact of charging to 100% on your battery’s health.

In our previous diesel car, we would usually let the fuel tank run down until it was in the red zone (about 1/8 full) and then fill it up. The exceptions would be when we’re about to go on a long journey, and so we would fill up before departing to save having to stop off on the way.

With our electric car, we follow the advice of generally keeping the charge level between 20% and 80%. A quick web search finds several different articles backing this up. But we do also charge to 100% sometimes:

When you should charge to 100%

If you’re about to go on a journey where you need the range, then charging up to 100% makes sense. This is especially so if you’re charging at home, as this will be much cheaper than paying to do so at a public charger. There’s no point in only charging to 80%, if this would mean that you have to stop and charge on your journey, when a 100% charge would allow you to complete your journey without a break.

Occasional charges to 100% are probably not going to contribute significantly to your battery’s degradation.

When you shouldn’t charge to 100%

The batteries in your car tend to work best at between 20% and 80% charge. Going outside this range can stress the battery, and doing so regularly may result in them degrading faster. This is also why rapid public chargers slow down the rate of charge after your battery reaches 80%.

Therefore, if you’re not planning a long journey, then it’s best to stop charging your car at around 80%. It’s also worth noting that some cars will limit the effects of regenerative braking above 80% charge, so your driving will be less efficient until your battery drops below 80% charge. Route planning apps should estimate how much charge you will need for your journey, and whether it’s worth charging to 100%.

Also, if you’re using a public charger and don’t need a full charge, then it’s courteous to stop charging at 80% and move your car to a non-charging bay, so that someone else can use it.

Is battery degradation a big problem?

Battery degradation is something that owners of electric cars should be somewhat aware of, but I also think that it’s less of an issue than some make it out to be. We didn’t buy our Nissan Leaf new – it was three and a half years old, and with around 33,000 miles on the clock. Its battery capacity isn’t quite as much as it would have been fresh from the factory, but we’re talking about a reduction of maybe four miles, which is less than 2%. If you extrapolate that, then by the time the car is around 10 years old, the battery degradation may reach 5-6%. But that still means that the battery can hold almost as much charge as new.

Obviously, we’ll do what we can to try and preserve the battery’s capacity for as long as possible, although there will be the occasional 100% charge when necessary.

Button battery charger

September 21, 2025 by Neil Turner

Battery chargers are just for AA and AAA batteries, right? Nope – it turns out you can buy rechargeable button batteries (also known as coin batteries) and a charger for them. Today, I’m reviewing this starter kit that I bought from Amazon (sponsored link) which includes a charger and four LIR2450 batteries.

The battery charger can charge two button batteries at a time. A red light shows that the battery is charging; it shows a green light when there’s no battery inserted, or the battery is fully charged. It’s not an intelligent charger, so it won’t tell you if the battery is dead, or give you an idea of progress.

As well as the provided LIR2450 batteries, this battery charger can also charge LIR2032 and LIR2025 batteries if you have these. These batteries should be compatible with any devices that take CR2450, CR2032 and CR2025 batteries, which aren’t rechargeable. It’s quite small, and gets its power via a USB-C cable, which is included. Batteries seem to take around two hours to fully charge.

I’ve got a Zigbee motion sensor that uses a CR2450 battery, and whilst it’s not needed its battery replacing yet, I can ensure that its new batteries are rechargeable. Disposing of batteries properly can be a pain, as they’re not supposed to go in household waste.

The starter pack, that includes the battery charger and four batteries, currently costs £16. Extra packs of four batteries seem to cost around £8 (sponsored link), so the equivalent of £2 each. That’s more expensive than buying the equivalent disposable CR2450 batteries, which can be had for about 50p each, but they should last longer and are better for the environment.

Cohhee Intelligent Battery Charger

September 9, 2025 by Neil Turner

Today I’m reviewing this Cohhee Intelligent Battery Charger (sponsored link) that I recently bought from Amazon, to recharge my AA and AAA batteries.

This isn’t the first ‘intelligent’ battery charger that I’ve bought – I have an older one, but it could only charge pairs of batteries (not single batteries) and didn’t detect batteries that could no longer charge. This Cohhee battery charger doesn’t have these faults; you can charge single batteries if needed, and mix and match between AA and AAA batteries. And, it’ll tell you if a battery is unable to be charged anymore.

Charging is quite fast – about 5 hours for AA batteries, and two hours for AAA. There’s a screen along the top that shows the charging progress of each battery. It’s relatively compact, and doesn’t need to plugged into a wall socket. Instead, it’s powered by a USB-C cable. It claims to have over-charging and over-heating protection too.

Having used it for a couple of months, I’ve found that the batteries I’ve charged up in it last longer than before. That’s probably because it charges the batteries individually, rather than as pairs, and identified the dud batteries that I could then get rid of.

Its normal retail price is only £9, but it’s on sale for £8 at the time of writing. Batteries not included.