Thermal shutdowns only when running on battery

[optiluca]

I have a Lenovo Thinkpad W510 for which I have bought a new (non-original) battery here https://www.amazon.it/Green-Extended-Batteria-Portatile-ThinkPad/dp/B01LWYK7BT/ref=cm_cr_arp_d_product_top?ie=UTF8 . I'm now seeing a very peculiar issue, where only when I'm running on battery, doing any sort of vaguely intensive activity (even just playing an HD video on youtube) triggers a thermal shutdown within 1-2 minutes.

I've tried monitoring what's going on with lm-sensors - the PC will be at an acceptable and plausible ~70 degrees, and then the acpitz-acpi-0 reading will suddenly shoot up to 128 degrees from one second to the next (I'm looking at this with watch -n 0.1 sensors) . I tried a few times, and once I also saw the Core 0 reading shoot up to 128 degrees.

This does not happen if I'm plugged into the mains, or even if I'm running with the original battery. How could changing the battery do this? My only guess is that it's not able to supply enough current (the laptop has the most power-hungry spec that was available), and for some weird reason the first thing to start misbehaving in this scenario is the temperature reading. Does that seem at all possible? I'd be tempted to try and disable thermal shutdowns and then have another go, to see if anything else breaks. Is that even possible? Should I just return the battery?

Thanks!

[NeddySeagoon]

optiluca,

Return the battery.

The temp reading might be right and it might be the battery that is causing the overheating.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

[optiluca]

Hi Neddyseagoon,

I'll probably do that - though I am quite intrigued as to how a battery could do this. Do you have any ideas?
_________________
# "Hmm, sounds like your system froze up."
# "I don't know why. It's about 80 degrees in here!"

http://www.rinkworks.com/stupid/cs_mincing.shtml

[NeddySeagoon]

optiluca,

A switched mode power supply, as found in all modern equipment is a negative resistor.
The output load is constant (Watts)
The battery voltage falls as it discharges, therefore the current drawn from the battery must increase.
The output power is a constant, the input power must be constant, so if V falls I must increase.
Power= I*V.

The losses in a switched mode power supply are related to the input current squared. So the thermal losses in the system increase as the battery discharges.

There are other effects, like the internal resistance of the battery that make all this worse.

I suspect you have a faulty battery and the internal laptop power supply can't cope with the way the input voltage falls.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

[Naib]

just to compliment Neddy's crashcourse in PowerElectronics

The equivalent series resistance may be at fault here. Something around the connection (be it the actual connector or internal to the battery) is presenting a higher than expected impedance. As mentioned, the laptop presents itself as a constant power system so if the volts drops the current must rise to maintain its needed draw. Some unexpected impedance would produce a local volt drop, reducing the voltage to the laptop which would compensate and draw more current which in turns drops more voltage ...

This would be additional heating at the SMPS and at the battery

The reason I suspect some form of unexpected equivalent series resistance is the time and the temperature... there must be enough energy to permit this heatrise while a degree of computer operation exists


If it was me I would get a reasonable rated resistor (For wattage, for impedance) and check the discharge and the voltage being presented under such load. I might even go as far as scoping it... but all this would be to satisfy an idle curiosity as the original supposition of a faulty/inappropriate battery would still stand and the steps would be a RTM
_________________

[NeddySeagoon]

Naib,

Hehe. We know its OK with the old battery ...
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.