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Is it bad if I run laptop without the battery connected?

By Kotu2 ยท 11 replies
Jul 28, 2009
  1. Is it bad if I just run my laptop without the battery and leave it plugged in? I want to do this so I wont ruin my battery, so what do you suggest is it fine?
  2. vnf4ultra

    vnf4ultra TechSpot Paladin Posts: 1,388

    No, it's not bad. The only downside I can think of is that bumping the power connection could cause an unexpected power down if the connector temporarily loses contact.
  3. Kotu2

    Kotu2 TS Rookie Topic Starter Posts: 72

    Okay thx thats the answer I was looking for :) Its just I don't wanna ruin the battery.but i do have the warranty but I dont wnna wait
  4. strategic

    strategic TechSpot Paladin Posts: 1,020

    If you plan on storing your battery, be sure to discharge it first :)
  5. Rick

    Rick TechSpot Staff Posts: 4,572   +65

    There's no harm, but there's also little good.

    Lithium ion batteries degrade over time... whether or not you use them. You won't really be saving your battery. Overcharging can damage batteries, but all Li-ion batteries have charging circuits which prevent that from happening. Charge cycles wear down Li-ion batteries as well, but the discharge rate is fairly slow (Takes several months for Li-ion battery to completely discharge on its own) and most batteries are rated at 500 charge cycles or higher.

    But again, it won't hurt anything. But if this is going to be inconvenient for you, there's really no benefit to offset the inconvenience.
  6. strategic

    strategic TechSpot Paladin Posts: 1,020

    This is also very true, my laptop is always plugged in (along with battery installed), but I will cycle the charge about once every2 months. After 4 years, my battery is just as good as it was.:)
  7. jobeard

    jobeard TS Ambassador Posts: 10,432   +801

    just fyi: while yours appears to boot w/o the battery installed, some laptops will not do so and require something to be connected. Frequently the A/C charger will not provide sufficient current to allow the boot-up.
  8. captaincranky

    captaincranky TechSpot Addict Posts: 12,541   +2,326

    This is an interesting research project. Some batteries need "deep cycling" (Ni-Cad) to prevent memory effects, some types, (Ni-Mh) claim "no memory", and some (Ni-cad again) can be ruined by a total discharge. Li-ion, I'm in the dark about. If I charge my camera and and store it for only a couple of weeks, it needs a fair amount of time (?) to peak charge
  9. LookinAround

    LookinAround Ex Tech Spotter Posts: 6,491   +183

    An interesting research project indeed! I don't really know the answer myself but intrigued by the question, I just found the following interesting snippet from HP

    Optimizing battery life
    Typical lithium ion or NiMH (nickel metal hydride) batteries last longest (that is, accept the greatest number of full charges before displaying diminished charge retention) if not stored in your laptop when it's plugged into a wall socket. You can achieve optimal battery life by storing the battery at temperatures between 35 and 45 degrees Fahrenheit (typical refrigerator temperatures) at a 40-percent charge level. Before you take the laptop PC on the road, charge the battery up to 100 percent. When you return to your home or office, discharge it until the level reads 40 percent, and then place it in a waterproof bag and put it back into the refrigerator.
  10. Kotu2

    Kotu2 TS Rookie Topic Starter Posts: 72

    Huh all I needed was a simple no its not harmful XD
  11. Rick

    Rick TechSpot Staff Posts: 4,572   +65

    There are no memory effects with Li-ion batteries.

    "Memory" occurs with NiCad and NiMH because the electrodes crystallize, reducing the surface area exposed to the electrolyte... This reduces or even eliminates the battery's ability to deliver and/or accept a charge. When one of these batteries are discharged and recharged, the crystals begin to dissolve which increases the battery's performance again.
    It's true that NiCad is far more sensitive and that NiMH. I don't think NiMH is immune to what people commonly refer to as 'memory', but it is very resistant at the least.

    Generally speaking, one reason NiCad is prone to memory effects is it suffers from crystallization on both electrodes: NiMH only has this problem with its cathode. The alloy used for the anode in NiMH batteries will vary from manufacturer to manufacturer... I don't know this, but I might conjecture that NiMH batteries the claim 'no memory effect' probably have an anode material that resists crystallization. The NiMH cathod is pretty much the same thing used in NiCad batteries and suffers the same problem.

    There are many Li-ion chemistries. I understand that some are superior to others in terms of holding a charge, but for the most part, Li-ion batteries do much better than NiMH in terms of self-discharging. The type of Li-ion batteries used for cameras may self-discharge more rapidly than those used for laptops, for example.

    I usually see cycle life for Li-ion batteries used in computers around 500 cycles. NiMH, is about 1200 and NiCad is over 2000 (as long as your battery doesn't completely crystallize! :))
  12. Rick

    Rick TechSpot Staff Posts: 4,572   +65

    Oooh, I almost missed this.

    Interesting, but "frequently" is probably an overstatement -- I can't recall ever seeing this behavior.

    Some laptops will complain that your AC power adapter doesn't deliver enough power to boot, but that's only if you. 1.) Have a problem with your AC adapter 2.) Using the wrong AC adapter

    I've also never seen a laptop discharge under load while being plugged in, which I assume would be the result of an AC adapter not supplying enough current. But, it wouldn't surprise me if some very old laptops needed the battery to 'complete the circuit', but for extra power during boot up... well, that sounds like bad design. I don't remember seeing that behavior even with very old laptops (early 90s).
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