Singapore parenting, practical reviews and tech notes

Category: Others

This AirTag AA Battery Extender Is Ridiculous, Useful, and Mathematically Kind of Brilliant

Howard Toh

I unboxed one of those AirTag accessories that sounds slightly ridiculous until you think about the use case properly: an Apple AirTag enclosure replacement that runs on 2 AA batteries instead of the usual CR2032 coin cell.

And yes, I know. It makes the AirTag bigger. This is not the sleek little disc you hide elegantly in a wallet. This is the version you chuck into luggage, cable-tie to a kick scooter, or throw into a laptop bag and then forget about until Future You needs it. Honestly, Future You deserves nice things.

Unboxed AirTag AA battery extender with AA batteries, shell, screws, tool, and mounting accessories
The unboxed kit: enclosure, AA battery compartment, screws, tool, adhesive bits, and the usual small parts designed to disappear if you sneeze.

What this thing actually is

The product is basically a rugged AirTag enclosure that replaces the normal button-cell battery setup with a larger battery compartment for two AA batteries. The packaging claims waterproofing, AA battery support, and more flexible mounting options.

Retail packaging for an ultra-long battery life extender for Apple AirTag using AA batteries
The box calls it an ultra-long battery life extender for AirTag. Big claim, but the battery math is not nonsense.

The appeal is simple: AirTags are brilliant until you need to keep replacing CR2032 cells. Apple’s official claim is “more than a year” of battery life, but real-world use can be shorter, especially if you make the AirTag play sounds often. I have seen people mention closer to 6-12 months depending on usage, which is fine for keys, less fine for things you don’t want to keep opening up.

The battery math, because of course I did the battery math

A typical CR2032 coin cell is around 220-240 mAh at 3V. Let’s use 235 mAh as a reasonable middle number.

A decent AA lithium battery can be around 3000 mAh at 1.5V. Two AA batteries in series give you roughly 3V, which matches the AirTag’s expected voltage range better than one AA alone. When batteries are in series, voltage adds, but capacity in mAh stays roughly the same.

So the simplified comparison looks like this:

  • CR2032: about 235 mAh at 3V
  • 2x AA lithium in series: about 3000 mAh at 3V
  • Capacity ratio: 3000 / 235 = about 12.8x

If Apple says the AirTag can last about 12 months on a CR2032, then the very optimistic theoretical number becomes:

12 months x 12.8 = 153.6 months, or about 12.8 years.

That is the “spreadsheet is feeling generous” number. Real life will be worse because batteries have self-discharge, voltage curves are messy, contact resistance exists, weather matters, and electronics never read your calculations before disappointing you. But even if we haircut that down quite aggressively, a claim of just over 10 years theoretically is not crazy when using good lithium AA batteries.

With alkaline AA batteries, the numbers can still be much better than CR2032, but I would be more cautious. Alkalines are cheaper, but they are also more likely to leak if left alone for years. And if this thing is going into luggage or a bag you don’t inspect often, battery leakage is exactly the sort of quiet betrayal that ruins your day later.

Use lithium AA batteries if you can

My practical advice: if you are buying this for long-term placement, use good AA batteries, preferably lithium. The whole point of the product is to stop thinking about the battery. Saving a few dollars on bargain-bin alkalines and then discovering battery leak gunk in your tracker years later feels like losing at a game nobody told you was running.

Where I would actually use this

Two assembled black AirTag AA battery extender enclosures with keyrings attached
Fully assembled, it is definitely no longer tiny. But for luggage, scooters, and bags, that is not really the point.

This is not for every AirTag use case. I would not put this in a slim wallet. I probably would not use it on keys unless I wanted my keychain to look like it had a side job.

But for these, I get it:

  • Checked luggage
  • Cabin bags
  • Kick scooters
  • Laptop bags
  • Tool bags
  • Storage boxes you only touch once in a while

Basically, anything where size is less important than “please keep working without making me remember another tiny battery purchase”.

The trade-off

The trade-off is obvious: it makes the AirTag much bulkier. But that bulk buys you a much larger energy reserve, better mounting options, and less battery anxiety. For luggage and gear tracking, that is a trade I can live with.

Would I use this for every AirTag? No. Would I use it for the AirTag I intend to forget inside a bag for a very long time? Absolutely.

View the AirTag AA battery extender on Shopee

Affiliate note: some links may be affiliate links. If you buy through them, I may earn a small commission at no extra cost to you. This helps fund the very serious scientific pursuit of buying oddly useful things and then doing battery math on them.

When Old Melodies Meet: Mixing 張洪量’s Classics

Howard Toh

Discovering a Familiar Sound

Recently, as I was listening to 張洪量’s “心爱妹妹的眼睛,” something about the melody struck me as oddly familiar. I couldn’t shake the feeling that I’d heard those chords before, and after a few repeats, it finally clicked—the chord progression was the same as another 张洪量 classic, “你知道我在等你吗.”

Both songs have that signature C–Am–F–G chord progression running through most of their verses and choruses. It’s a classic progression, but I was surprised at how closely the two songs mirrored each other, not just in mood but also in musical structure.

A Mashup Idea Is Born

Once I noticed this, I was curious: what if these two songs weren’t just similar, but actually mixed together? Could I blend their vocals or melodies and make them feel like a single new song?

So I decided to give it a go. I fired up GarageBand, brought in both tracks, and started tinkering. There was one big difference between the two: “心爱妹妹的眼睛” is noticeably slower than “你知道我在等你吗.” To get them to fit together, I had to adjust the tempo of “心爱妹妹的眼睛” so it would match up rhythmically. With a bit of slicing, synchronizing, and some patience, the mix began to take shape.

The Mixing Process

I used the instrumental/backing track from “你知道我在等你吗” as the foundation, then overlaid elements from “心爱妹妹的眼睛.” Surprisingly, everything fit together beautifully once the tempos were synced. The magic of a shared chord progression brought the melodies together smoothly, and I was able to create a blend that retained the spirit of both originals.

What I love most about this experiment is how it highlights the underlying connections in music—sometimes, songs we think are completely different are actually built on the same musical foundations. All it takes is a bit of curiosity (and maybe a DAW like GarageBand) to uncover those links.

Listen and Let Me Know Your Thoughts!

I put the finished mashup on YouTube for fun. If you’re a 張洪量 fan, or just enjoy clever musical experiments, give it a listen! I’d love to hear what you think, and whether you know of other songs that secretly share the same DNA.

I did a 5-day water fast with daily blood glucose and ketones measurements

Howard Toh

I have been on Intermittent Fasting (IF) for over a year and I gradually increased my IF from 16/8 to 18/6, 20/4 and sometimes reaching 24 or 25 hours without food. There are so many resources on the web on the benefits of IF such as reversing insulin resistance, weight loss (because one tends to eat lesser with IF and creates a sustainable calorie deficit) and many more.

However, to get some of the better benefits such as fat burn (ketosis) and autophagy, a fast that is beyond 24 hours is required. This is because you may already spend 24-48 hours depleting your glycogen store in your liver and muscle before you can enter ketosis. This is the time that autophagy can also begin. While on a keto diet or IF, one tends to drink black tea / coffee but that is thought to interrupt the autophagy process by stimulating insulin response. As such, I planned to be extremely strict on my 5-day water fast – nothing except plain water.

I started on Sunday, 28 November 2021 at 6:30pm – that is the time I swallowed my last bite of dinner. I at like there was no tomorrow. As a result, I weighed in at 90.45KG that night. Although I started on Sunday 6:30pm and is to break my fast at the same time on the following Friday, let’s take Monday as Day 1 for simplicity.

I bought a tube of ketone urine test strips in advance but I gave it some thought and felt that I should invest in a more precise data collection since I’ll be committing so much to this 5-day fast. It would be a waste if I had to fall back on test strip indicators that are subjective. I will then use Glucose-Ketones-Index (GKI) to see how am I doing in terms of ketosis.

What is GKI (Glucose Ketones Index)

Day 1

I went out to grab blood glucose and ketones strips for my Abbott Freestyle Optium Neo Blood Glucose & Ketones Monitoring System

  • Mood: Totally fine – this is within my usual IF practice anyway
  • Energy level: Great
  • Mental clarity: good
  • Blood Glucose: 4.8 mmol/L
  • Blood Ketones: 0.3 mmol/L
  • GKI: 16 (Not in ketosis)
  • Weight: 88.75 kg
  • Remarks: My body has yet to fully use up the glycogen store due to my high carb meal the day before. I expect this to be depleted within the next 12-24 hours.

Day 2

  • Mood: A little grumpy
  • Energy level: A little lesser than normal
  • Mental clarity: good
  • Blood Glucose: 3.6 mmol/L
  • Blood Ketones: 2.1 mmol/L
  • GKI: 1.7 (Therapeutic ketosis)
  • Weight: 88.25 kg
  • Remarks: I jumped straight into ketosis. The hunger was okay but my mind is

Day 3

  • Mood: neutral
  • Energy level: it’s alright
  • Mental clarity: good
  • Blood Glucose: 3.2 mmol/L
  • Blood Ketones: 3.6 mmol/L
  • GKI: 0.9  (Highest therapeutic ketosis)
  • Weight: 87.2 kg
  • Remarks: Technically hypoglycaemic if based purely on blood glucose level. However, I am burning fats and ketones so this level of glucose is still safe. The body is using protein to produce the little bit of glucose needed by certain parts of the body that cannot burn fat/ketones.

Day 4

  • Mood: grumpy
  • Energy level: lower than usual
  • Mental clarity: great
  • Blood Glucose: 3.3 mmol/L
  • Blood Ketones: 4.7 mmol/L
  • GKI: 0.7  (Highest therapeutic ketosis)
  • Weight: 86.75 kg
  • Remarks: I can’t take my mind of food. Every time I open FB/IG, someone is posting about food they bought / eating or how-to style videos about preparing food. I went into Grab app and attempted to schedule some deliveries for the next day ….

Day 5

  • Mood: surreal
  • Energy level: lower than usual
  • Mental clarity: great
  • Blood Glucose: 3.1 mmol/L
  • Blood Ketones: 6.2 mmol/L
  • GKI: 0.5  (Highest therapeutic ketosis)
  • Weight: 85.4 kg
  • Remarks: I walked for about 2.4km to run errands (Grab groceries and such for my breaking of fast). Because of that exertion, I hit an all time high of 6.2 mmol/L of ketones and 3.1 mmol/L of glucose.

Data Collected

May be an image of text that says "Howard's Ketones, Glucose & GKI Ketones (mmol/L) 8 16 Glucose (mmol/L) GKI 6 4.8 20 3.6 6.2 4.7 3.6 3.2 15 2 2.1 3.3 0.3 1.7 3.1 10 0 29/11/2021 0.9 30/11/2021 0.7 5 01/12/2021 0.5 02/12/2021 Date 0 03/12/2021"

May be an image of text that says "Howard's weight, body fat and muscle mass Weight (KG) 100 90.45 88.85 Body Fat (KG) 88.75 80 Muscle Mass (KG) 88.25 87.5 87.2 60 86.75 58.20 86.05 85.4 58. FI 57.90 40 28:76 57.90 PM 57.70 58.20 27.45 26.89 20 28/11 pm 26.92 26.43 26.16 29/11 pm 25.94 1/12 am 24.70 24.77 2/12 am 3/12pm pm"

My final blood glucose and ketones blood test on Day 5

Conclusion

As you can see, despite not eating for 5 days, my blood glucose level did not drop below 3 (which would have been dangerous). This is no coincidence as the body just produces enough glucose to keep some parts of my body functioning while the bulk of my body ran on fats and ketones. Will I do it again? Yes – twice a year. There is no need to go on a 5-day fast that often. However, I am contemplating going on a weekly 48-hour fast on top of my IF.

A word of warning: if you are diabetic, please consult a doctor first because instead of ketosis, you can slip into ketoacidosis which is potentially life threatening!

 

Why I took Moderna for my booster after 2 Pfizer shots

Howard Toh

Disclaimer: This should not be taken as medical advice as I am just sharing my experience as someone who had taken 2 Pfizer shots and decided to take Moderna as my booster.

I had my first and second vaccinations back in March and April 2021 and that made me eligible for my booster yesterday (19 October). I made the conscious effort to “mix” vaccines by going for Moderna even if it meant that I had to travel slightly further to a vaccination centre that carries Moderna when there’s already a Pfizer vaccination centre within a 5-minute walk from my home. I am also aware of the generally worse side effects based on anecdotal accounts from Moderna recipients.

So why did I still choose to bring this upon myself?

First of all, I have no doubt that Pfizer and Moderna are both great mRNA vaccines. They both greatly reduce the chances that one will get hospitalised due to severe symptoms from Covid-19. However, in the recent months, there has been early reports that Moderna is more effective than Pfizer against the Delta variant.

In a study of more than 50,000 patients in the Mayo Clinic Health System, researchers found that the effectiveness of Moderna’s vaccine against infection had dropped to 76 per cent last month – when the Delta variant was predominant – from 86 per cent early this year.

Over the same period, the effectiveness of the Pfizer-BioNTech vaccine had fallen to 42 per cent from 76 per cent, researchers said.

Source: https://www.straitstimes.com/world/united-states/moderna-may-be-superior-to-pfizer-against-delta

Historically, there were findings of vaccine mixing (heterologous prime-boost) could be more immunogenic than single vaccines (homologous prime-boost). While such a study has yet to be conducted on a Pfizer-Moderna combination, authorities around the world have begun allowing mixing of vaccines to ease the burden on logistics and supplies.

In Singapore, our authorities view mRNA vaccines as “similar” and have therefore officially allowed the mix as of 17 September 2021.

Source: https://sg.news.yahoo.com/covid-booster-pfizer-biontech-moderna-vaccine-134827443.html

Side effects of mixing Pfizer and Moderna Vaccines

Before going for the booster shot, I tried searching for side effects of mixing the two vaccines but without success. So here’s my account of the 36 hours post vaccination:

19 October 2021

9:30am: I arrived at the vaccination site ahead of my 10am appointment. I was made to acknowledge that I am switching from Pfizer to Moderna – twice. Once at the registration counter and then at the vaccination booth.

9:36am: Vaccination done. Time for the 30-minute on-site observation.

10:06am: Called to the discharge counter to check if I’m okay. All good. I then took a 4km casual walk home (strenuous exercise is not allowed so I made sure that it was a casual stroll).

I technically had the day off from work (vaccination benefit) so I chilled for the most part of the afternoon.

4pm: Short nap – no fever yet.

6pm: Felt a bit lethargic. No fever yet. Unable to get up to send my daughter for her piano class.

7pm: Got up for dinner. No fever yet. Realised that there’s some work to be done.

8pm: Slight fever at 37.9 C.

10pm: Fever at 38.5 C.

11pm: Fever at 39 C, chills kicking in. This continued through the night.

20 October 2021

7am: A lot of pressure on my entire face – like it’s going to explode. I could barely wake my kids up for school. Temp: 38.9 C.

3pm: I only got up at 3pm and temperature was 38.1 C. Attended a few meetings and left home to get my medical leave to cover my absence for the good part of the work day.

7pm: Temperature at 37.6 C (Might be the paracetamol that I finally took)

10pm: Temperature 38.4 C + chills. Here we go again.

I’ll update this post until I’ve stopped experiencing any effects of the vaccination.

Conclusion about mixing Pfizer / Moderna for booster shot

It has always been anecdotally known that Moderna recipients suffer longer  fevers, headaches and chills compared to Pfizer recipients. This is why I am not at all surprised if my symptoms is going to go on for another day or two. This is within my expectation and I made that informed choice.

Should you mix vaccines? My personal opinion is yes. Mixing vaccines could potentially offer a wider spectrum of coverage. Even if it does not offer significant benefits, there should not be any ill effects of mixing the vaccines otherwise this practice would have been banned around the world. At the end of the day, this is your personal choice. Mixing or not, just get your 2 +1 vaccinations done!

 

5-HTP – my personal recommendation for moodiness, anxiety, depression and general sleep difficulties

Howard Toh

If you feel moody, anxious, depressed, stressed or have any combination of these, I would like to personally recommend you to take 5-HTP supplements.

5-HTP is an amino acid that is integral in the production of serotonin, a neurotransmitter that causes happiness and positivity. Serotonin is produced by the body from tryptophan and 5-HTP is the immediate precursor to serotonin.

5-HTP is a precursor to serotonin and has been studied extensively for its role as a treatment in depression and weight loss. It also has an important role in sleep regulation, appetite control, immune function and cardiovascular health.

Truth be told, I don’t take this every single day. I use it specifically when I have had late nights and felt that I really need to sleep well tonight. Quite consistently, I get restful sleeps without my mind going wild about things I have to do the following day or reflecting on things that have happened. The supplements are not expensive and are pretty safe to consume.

You can get the same brand that I’m taking (NOW Foods 5-HTP 100mg) or get it from your own preferred supplement company.

Where to buy 5-HTP in Singapore

If you prefer buying from Shopee Singapore, these are practical 5-HTP options to compare. Availability and pricing can change, so check the product page before ordering.

Some Shopee links above are affiliate links.