How much can you trust to Windows Battery report?

[frozensun]

First, I would like to buy a Surface Book from a person who is a bit further away from me, so say it blindly.
I asked him to take a picture of the Windows battery report and I got this from the pictures.
According to this, if it is relevant at all, the batteries are not charged often, the capacity is not so bad for a 7-year-old laptop.
How much can you trust this and tell yourself that the batteries are relatively okay?
I have a warranty on this laptop but it doesn't apply if the batteries are bad very likely.
The seller will just say you bought an 8 year old device.
I say this from experience last time I also blindly ordered a Surface Book which had good capacities but a little more cycles.
When I came home and recharged the device a couple of times, the capacity was almost halved and the battery in the tablet could not last more than half an hour, even though it showed here in the right corner of the clock that it should last 2 hours.
Thank God I returned the device from another problem.

[ki8aras]

4 minutes ago, frozensun said:

First, I would like to buy a Surface Book from a person who is a bit further away from me, so say it blindly.
I asked him to take a picture of the Windows battery report and I got this from the pictures.
According to this, if it is relevant at all, the batteries are not charged often, the capacity is not so bad for a 7-year-old laptop.
How much can you trust this and tell yourself that the batteries are relatively okay?
I have a warranty on this laptop but it doesn't apply if the batteries are bad very likely.
The seller will just say you bought an 8 year old device.
I say this from experience last time I also blindly ordered a Surface Book which had good capacities but a little more cycles.
When I came home and recharged the device a couple of times, the capacity was almost halved and the battery in the tablet could not last more than half an hour, even though it showed here in the right corner of the clock that it should last 2 hours.
Thank God I returned the device from another problem.

i have never used windows' battery report myself , but if you are holding out on it, just tell the seller to show you a hwinfo64 screenshot of the battery status

[frozensun]

2 minutes ago, ki8aras said:

i have never used windows' battery report myself , but if you are holding out on it, just tell the seller to show you a hwinfo64 screenshot of the battery status

Oh I forgot about that..you mean wear level?

[ki8aras]

Just now, frozensun said:

Oh I forgot about that..you mean wear level?

yeah, wear level is a pretty good indicator (if not the only one we have access to ) of battery health

[frozensun]

12 minutes ago, ki8aras said:

yeah, wear level is a pretty good indicator (if not the only one we have access to ) of battery health

So how much should it be in % as a good indicator?

[Eigenvektor]

1 hour ago, frozensun said:

So how much should it be in % as a good indicator?

As close to 100% as possible, I'd say.

 

Since Windows reports full charge capacity as 15,097 mWh out of 17,902 mWh (84%) and 44,512 mWh out of 51,000 mWh (87%) I would expect the wear level indicator to match these. I'd say both values are still reasonable.

[porina]

1 hour ago, frozensun said:

When I came home and recharged the device a couple of times, the capacity was almost halved and the battery in the tablet could not last more than half an hour, even though it showed here in the right corner of the clock that it should last 2 hours.

It is basically up to how good the battery management chip is doing its job. All Windows does is read what the battery reports. If the system had low usage, the data in the battery may be out of date. Cycling the battery (full charge/discharge) should help it give more realistic data.

[venomtail]

I'd say battery cycle count is a good reference for an ideally worn battery. The absolute best way to see the real performance is to have aggregated real past recorded performance, such as AccuBattery on Android and I assume similar apps on Windows.

 

Such as for my phone and old laptop, the cycle count severely mismatched actual battery performance, was way too optimistic.

[Eigenvektor]

7 minutes ago, porina said:

All Windows does is read what the battery reports.

This. And most likely the wear level indicator of HWInfo64 isn't going to do anything other than show the values returned by Windows Management Instrumentation (WMI), which in turn gets its values from the battery. So the data source is the same in all cases, just the presentation of the data may be slightly different.

 

Ideally you'd want to charge the battery to full, then let the machine run with some constant load and get a report of battery charge over time to see if it has any issues like suddenly dropping from 80% to 20% in a matter of seconds or similar.

[frozensun]

It's a 7 y old laptop guys so I can not expect miracles.

I just asked on how trustful these data can be.

Because I had weird issue with last laptop I  purchased and returned to seller.

[frozensun]

So no one replied me on how much tolerance of a wear level in % for good battery would be?

[TheLANguy]

7 hours ago, frozensun said:

So no one replied me on how much tolerance of a wear level in % for good battery would be?

For a laptop that age, up to 30% is good.

Sometimes the data will be incorrect and show 0% wear.

[Lurking]

If battery operation is important, buy a new and more efficient device.

 

What written warranty do you think you get assuming this is private sale? Batteries aren't even under warranty for new devices since they are wear items (unless there is extreme failure or degradation). 7 year old batteries may only be good for an hour, or some minutes. YMMV. But not for hours of use like a new device. 

 

The data are the data. That's all a manufacturer gives you without special battery testing tools. The seller could have sent a completely different laptop's screenshot. So it more depends how much you trust the seller than Windows.