In order to extend the life of the battery, some people say that it is
best to charge it at a slow speed.
Others say that quick charge is fine as long as the battery does not
become too hot.
Yet others claim that quick charge is even _better_, because the charge
time is shorter.

I always thought that a charge current of about 1000 mA is most ideal,
but AccuBattery shows this speed as very low and in red, as if it is bad.

I saw a review of smartphones where a charge time of 1.5 hours was called
'long', whereas I always considered 2.5 hours as normal.

Does anyone know what the most ideal charge speed would be?

Am 16.07.24 um 12:35 schrieb Siard:
> In order to extend the life of the battery, some people say that it is
> best to charge it at a slow speed.
> Others say that quick charge is fine as long as the battery does not
> become too hot.
> Yet others claim that quick charge is even _better_, because the charge
> time is shorter.
>
> I always thought that a charge current of about 1000 mA is most ideal,
> but AccuBattery shows this speed as very low and in red, as if it is bad.
>
> I saw a review of smartphones where a charge time of 1.5 hours was called
> 'long', whereas I always considered 2.5 hours as normal.
>
> Does anyone know what the most ideal charge speed would be?

Charging speed is limited by the electronics. Newer phones can charge
from 20% to 80% in roughly 30-45 minutes given the charger has the
necessary power output.

Avoid wireless charging at that speed. The battery becomes too hot.

--
"Gutta cavat lapidem." (Ovid)

On Tue, 16 Jul 2024 12:35:09 +0200, Siard wrote:
> Does anyone know what the most ideal charge speed would be?

There is no simple answer to this. The question just raises
many more questions.

Battery type and chemistry?

How long do you expect the battery to last?

Is it easily replaced?

The 'conventional wisdom' was that fast charging leads to
shorter battery life. Most phones now have a fast charging option.
My Oppo phone fast charges at 33W (11V,3A), which is enough to charge
it in about one hour. Oppo claims the battery can take up to 1500
charge/discharge cycles before battery capacity falls to 80%.
As I only charge my phone once or twice a week, it will probably
be in the recycling bin long before the battery wears out.

I only use the fast charger when necessary. For most charges,
I connect the phone to an ordinary 10W (5V,2A) charger.
Does this extend the battery life? I don't really know.
The phone gets warm, but not excessively hot on the fast
charger. It is noticeably cooler on a slow charge.

After 18 months of use, there is no measurable reduction
in battery capacity. I usually get 3-4 years out of a phone
before it gets broken or becomes redundant. I haven't lost
one because of battery failure yet....

In comp.mobile.android, on Tue, 16 Jul 2024 12:35:09 +0200, Siard
<xx@xx.invalid> wrote:

Bear in miund, I have Accu-battery but I've barely looked at it and I
dont' know anything about it.

>In order to extend the life of the battery, some people say that it is
>best to charge it at a slow speed.
>Others say that quick charge is fine as long as the battery does not
>become too hot.
>Yet others claim that quick charge is even _better_, because the charge
>time is shorter.
>
>I always thought that a charge current of about 1000 mA is most ideal,
>but AccuBattery shows this speed as very low and in red, as if it is bad.

Nonetheless, I suspect that the speed is written in red only because
they think it's very low, so that leaves you with one fewer question.

>I saw a review of smartphones where a charge time of 1.5 hours was called
>'long', whereas I always considered 2.5 hours as normal.
>
>Does anyone know what the most ideal charge speed would be?

The reason eveyrone thinks slow charging is better is because we were
all told that as infants with regard to lead acid car batteries. With
them, if you charge too fast, I think it's that PbSO4 gets trapped under
lead that is being redeposited on the lead plates, so it's no longer
floating in the electrolyte and no longer avaiable for conversion to
lead and thus no longer available later to make electricty. it's
called spongy lead.

Phone batteries work with different substances, but they might still
work in an analogous manner, or not. If you have time you could check
out batteryuniversity.com but to fully understand, you have to allocate
4 years. Plus tuition and room and board, and if you're married, I
don't think they'll let you bring your wife.

On 7/17/2024 9:27 AM, micky wrote:

> The reason everyone thinks slow charging is better is because...

One reason perhaps is because with slow charging there's less heat
generated, and excess heat is not good for a phone including the battery.

As an example of ONE, my Galaxy S10+ turns 5 years old in 2 months and I
have yet to NOTICE any battery problems. But of course that's with MY
phone and usage. YMMV.

I've always used overnight charging with a wireless charger. The charger
originally came with a 10 watt power supply and I replaced it with a 3
watt power supply. It obviously takes longer to charge with this
modification but I don't notice it much while sleeping. When I have
picked the phone up during the night I didn't NOTICE any heat so the mod
seems to working. And PERHAPS contributed to the phone's longevity...

Siard, 2024-07-16 12:35:

> In order to extend the life of the battery, some people say that it is
> best to charge it at a slow speed.
> Others say that quick charge is fine as long as the battery does not
> become too hot.
> Yet others claim that quick charge is even _better_, because the charge
> time is shorter.

The latter one makes no sense since high temperature during charge is
always bad for the battery. Also the electrodes in the battery degrade
faster the more power they have to transfer.

> I always thought that a charge current of about 1000 mA is most ideal,
> but AccuBattery shows this speed as very low and in red, as if it is bad.

1000 mA at 5 Volts would be around 5 Watts. Even with USB-PD and 9 or 18
Volts this would be only 18 Watts. Modern Smartphones usually charge
using 30-60 Watts depending on the number of batteries used. Higher end
phones have two or more batteries in parallel so they can use higher
charge power which is distributed evenly along multiple batteries

> I saw a review of smartphones where a charge time of 1.5 hours was called
> 'long', whereas I always considered 2.5 hours as normal.

Well, nowadays some devices manage to charge nearly 100% within less
than an hour. But I consider 1-2 hours as normal for a charge from
nearly 0% to 80-90%.

> Does anyone know what the most ideal charge speed would be?

There is no generic "ideal charge speed". Or in other words: any speed
is ok, as long as the battery will not get damanged by the charge process.

The device manufacturer designed or choose the charge controlling
procedure and the battery which you can not change. Usually mobile
devices are designed to work at least 2-3 years without any major
degradation of the batteries.

Also the charge process often adaptive: it will start with a higher
current in the beginning and as more the battery is charged, the current
will be reduced. Some devices will have adaptive charging during night
time when the device is not used regularly, so the charging process will
take a couple of hours but only with reduced current to increase the
battery life.

As a rule of thumb: rechargable LiIon batteries can take 500-1000 charge
cycles before the capacity starts to degrade. So when you recharge the
device from nearly empty to nearly full every two days this means around
3-6 years of use without any major capacity loss. But even after that
time, the capacity loss is gradual and you may notice that the battery
only lasts for 30 hours and not 40 hours as before.

Also keep in mind that apps like Accubattery can only measure the charge
but not change it without root access.

--
Arno Welzel
https://arnowelzel.de