Long story short, my laptops DC input is no longer working. Yes, I’ve tested every aspect of the power supply. I even measured the motherboard input voltage, and it is being properly fed. I suspect a faulty DC-DC converter.
So, I had this idea of removing the battery permanently, and instead emulating it with a power supply with matching voltage. I don’t really need the battery anyway (I mostly use a laptop for the form factor).
In theory, the laptop will then think it’s running off of battery power. Permanently. Are there any consequences in terms of performance that could arise from this? Of course, the power settings will need to be adjusted, but beyond that I’m wondering if there’s a hardware aspect that I cannot control.
If it’s from the last few years and the barrel input has an adjacent usb-c port it may accept usb power delivery
The port may not even be labeled for it
It just so happens that there’s a USB-C close to ir, but I think that’s just a coincidence as this laptop eats a lot more than even the beefier USB chargers. 20V, 14A. Some sort of square 4 pin connector I haven’t seen elsewhere.
ouch, usb c caps out at 100W afaik
The standard is up to 240w now
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It won’t work, it will try, then inspect the battery for its voltage and other stats via i2c, decide the battery is unsafe, and shut itself off.
I might be wrong, but systems I’ve worked with do this because they want to make sure the battery won’t explode, they have a battery management chip, either on the motherboard or in the battery, and this tells it whether the battery is safe to use or you should shut down, and if it can’t communicate it will probably assume it should shut down.
Personally I’d solder a new barrel connector on, or figure out where the dc-dc converter is and either replace it or backfeed.
It may be possible to get past that, I’ve seen people disassembling the battery to get the BMC and connecting the DC power supply to that instead.
It sounds way more risky than OP’s initial idea. I wouldn’t recommend taking apart batteries.
Yeah, none of this sounds like a recipe for anything except fire.
I think it would be fine. You’ll never try to charge it obviously.
Will the laptop be happy with that though? It might be expecting communication with the BMS. I’d just try it and see.
I’m fine with an “OmG Battaray err0r!!!1”-warning that I can send to /dev/null as long as it works. I’m more worried about performance, as this is a gaming laptop that is used as such.
Indeed, the laptop will almost certainly want to go into a lower power/slower mode, but I’m sure you should be able to configure it to force it to run at full speed, with enough effort anyways.
Make sure your power supply is rated for high enough watts/amps.
you are probably better off taking it to a computer repair shop to have the issue fixed or replaced, for peace of mind and probably liability reasons
I would venture a guess that as long as you match the voltage and current ratings of the battery then power itself wont be an issue, but there may still be some specific (possibly proprietary) data exchange that happens between the battery and the mainboard — depending entirely on the model of laptop — that confirms that the battery is legit, or to get diagnostic information. I don’t really have example of a laptop that does restrict the battery in such a manner, but this is just a concern that I have off the top of my head that I feel could be in the realm of possibility, and is worthy of concern. Potentially, it could function similar to how Apple iPhones will complain if third party components are used [1].
References
- “About genuine iPhone batteries”. Support. Apple. Accessed: 2024-10-25T20:27Z. https://support.apple.com/en-ca/103269.
This was a concern of mine as well, but from the looks of it, the battery is really simple with no apparent on board intelligence.
I’ve seen battery to wall power conversions before. As long as you’re feeding the laptop the power it expects from the battery, I don’t think it will care.
It may be easier to supply DC power directly to the soldering joints (at the right values after the converter) or even replacing that one component as using the jack itself.
That was my first idea, but I couldn’t identify any good solder targets.
The battery is DC. How do you plan to provide DC to the battery connection from AC outlets without a convertor?
Using a DC power supply, I assume.
Okay but why go through the battery interface and not try the old converter cable one? Much easier to splice the cable past the box than try to rig a connection to the underside of the laptop. Would also prevent any ‘no battery’ issues too.
I’m pretty sure OP had that converter in mind when writing “[…] emulating it with a power supply with matching voltage […]”.
