Thinkpads Forum

I'm not a great fan of laptop batteries. I'd like to simply have my Thinkpads run from the outlet. But of course without a battery, I'm risking losing everything in the event of power failure. The only thing I can think of is some sort of UPS like I now have my battery-less T410 plugged into. However, my UPS is not really road-ready, due to weight. Is there anything small and light that could serve as a portable UPS as well as possibly an "external" battery for power?

Something like a 250-350 VA UPS could be considered small enough to be "portable", depending on your needs. I just installed one (a CyberPower CP350SLG) for a client who wanted 5-10 minutes of runtime on a basic desktop.

Do bear in mind that most ThinkPads were not designed to run without batteries and will throttle if a working battery is not installed.

ajkula66 wrote:Do bear in mind that most ThinkPads were not designed to run without batteries and will throttle if a working battery is not installed.

To be more specific, Thinkpads that are shipped with a 65w AC adapter will be locked down to a lower clock speed when the battery is not attached. A 90w adapter is needed to allow full speed operation without batteries.
Example: X60 series, X200 series, X220; T60 series with integrated graphics

The same goes for models shipped with a 90w adapter, where you'll probably need the 135w adapter, but since I don't have any first-hand experience with this, I can't be certain.

Just curious, what is it that you do not like about laptop batteries?

If you would like to safeguard against power loss on the road, plugging in a battery seems like the most obvious solution. I can think of many advantages of a battery specifically designed for the laptop model compared to an external UPS, but can't really think of any arguments the other way around.

Olwe wrote:Is there anything small and light that could serve as a portable UPS as well as possibly an "external" battery for power?

Yes, a laptop battery.

Anything else would be just a pointless waste of time trying to solve a problem that does not exist.

The "on-board" battery -- at least for me -- has always seemed like a "weak sister" (to use 1950s slang). It nearly doubles the weight of the laptop, it always seems to want to get old and "silt up," that is, like a dam that gradually takes on sediment until its actual water volume is less than its dead silt volume. And even with a new and "healthy" battery, you're always worrying about when it will run out, a worry you don't need when trying to get work done. But then even when you're plugged in, the battery (at least as I've heard) tends to overcharge, which then shortens the already too short life even more. Now, if you could modularize the battery, make it "external," then you could choose the storage capacity you'd want -- or just go with a minimal UPS-like battery in the event of a power interruption. . . . At least these are my thoughts.

BTW, I'm running a T410 without a battery (plugged into a UPS). I have to because it doesn't seem to see its battery (won't use it or charge it). Am I running slower because of this? What about a T61?

BTW, I'm running a T410 without a battery (plugged into a UPS). I have to because it doesn't seem to see its battery (won't use it or charge it). Am I running slower because of this?

If you're using a 65w adapter, yes.

If you want to check, use a program that can monitor the CPU clock speed. There are lots of them: CPU-Z, Open Hardware Monitor, Perfmonitor, etc.

Then run a program that can use most, if not all, CPU cycles.
I usually use the benchmark function of 7-zip for a number of reasons:

1. single/multithreading mode (in a T410, it's best to set it to 4 or 8 threads)
2. 1-click start-stop
3. real-world use of CPU compared to synthetic benchmarks.

Before proceeding check the power profile and make sure it's not set to "Battery Optimized" or "Power Saver".

Now, as you run the test, you should see the CPU clock speed increase (you should know the max speed of your CPU).
If you have an i5-520M (2.4GHz) but you never hit above 1.6GHz and don't reach critical CPU temperatures, then it's obvious that yes, your CPU's clock is being throttled back.

What about a T61?

Same issue. I think this issue has existed since the T60/X60/R60 generation.

The root cause of this issue is a protection mechanism: Lenovo's engineers have determined that in certain scenarios, peak power consumption exceeds the output of the standard AC adapter. When this happens, the power circuits use the battery as well (you might notice that the "Time to finish charging" suddenly increases). Without the battery, this is impossible, so the max CPU speed is lowered to reduce power consumption, and prevent the laptop from drawing more current than can be supplied by the AC adapter.

Using a more powerful AC adapter will remove the speed limit, and you can use the laptop to its full extent.

Most Thinkpads come with 65w adapters by default; 90w is needed to run them at full speed without batteries.

A number of models, usually those with discrete graphics (ATI/AMD or nVidia) usually come with 90w adapters. I'm not sure if there are issues in this case, but a 135w adapter exists and is probably needed.

The W series have 135w and 170w adapters, but I'm not familiar with their power requirements. More info can be found here: http://forum.thinkpads.com/viewtopic.php?f=48a&t=94554

You are grossly exaggerating all the "problems" with batteries.

Olwe wrote:It nearly doubles the weight of the laptop

A huge exaggeration, except in some very extreme cases. Certainly not in the case of T61/T400, where the laptop without battery weighs ~2kg, and the heaviest possible battery is only 500g (that is, about 25% of the laptop weight).

Olwe wrote:And even with a new and "healthy" battery, you're always worrying about when it will run out, a worry you don't need when trying to get work done.

So your alternative is to have no battery at all. This way you don't have to worry while getting work done on battery, because you can't get any work done on battery.

Olwe wrote:But then even when you're plugged in, the battery (at least as I've heard) tends to overcharge, which then shortens the already too short life even more.

Again, huge exaggeration, based on my >10 year experience with a dozen or so laptops and laptop batteries. Not to mention that, on Thinkpads, as well as a few other laptops, it is possible to control charging thresholds, for those of us obsessed with "not overcharging the battery".

Olwe wrote:Now, if you could modularize the battery, make it "external," then you could choose the storage capacity you'd want -- or just go with a minimal UPS-like battery in the event of a power interruption

Yes, you could, but why bother? You can already choose the battery storage capacity in many cases, and go with the smallest one available. Modularization in general is good, but an external battery is bound to be much more cumbersome, and probably heavier to lug around, than something that is an integral part of the laptop body (whether detachable or not).

So you are essentially looking for a solution, which may be interesting in theory, but in practice, comes with pretty big drawbacks, very few (if at all) benefits, and really aims to solve a very minor issue, which you totally blew out of proportion.

BTW, I'm running a T410 without a battery (plugged into a UPS). I have to because it doesn't seem to see its battery (won't use it or charge it).

Well, either the battery is defective, or there's a fault in the charging circuit. It would be nice if you can borrow a known working T410 battery to check if your laptop detects it.

Ah. Please allow me to address your points one by one.

Olwe wrote:It nearly doubles the weight of the laptop

The T410 weighs "starting at 2.27 kg", and a 6-cell battery for it weighs 0.340 kg (a 9-cell battery weighs 0.500 kg). As a comparison, even the smallest UPS system would weigh several kilograms. For on-the-road usage, a battery is much less weight to carry.

Olwe wrote:it always seems to want to get old and "silt up," that is, like a dam that gradually takes on sediment until its actual water volume is less than its dead silt volume.

Lead-acid batteries used in UPS units also age, and arguably age faster than Li-ion batteries. A properly maintained UPS system should have its battery replaced once a couple of years, even though it may have been used only a handful of times during that period. On the contrary, a Li-ion laptop battery usually have a useful life of at least 2 or 3 years when used (completely discharged and recharged) daily. With lighter usage, its life will be even longer.
I have a new old stock battery in my T61. It was manufactured in 2008, sat in a warehouse somewhere, and first used in 2014. Right now it has a cycle count of 104 (i.e. the amount of energy ever discharged from this battery is equivalent to 104 times its capacity), and still holds 75% of its design capacity. I say that's very impressive for a 7-year-old battery.
(Sanyo cells, for those who're wondering)

Olwe wrote:And even with a new and "healthy" battery, you're always worrying about when it will run out, a worry you don't need when trying to get work done.

The same applies to a UPS, whose battery level you also have to monitor. And your operating system should give you ample warning that the battery is going to run out in either case.

Olwe wrote:But then even when you're plugged in, the battery (at least as I've heard) tends to overcharge, which then shortens the already too short life even more.

That is not true. Any commercial Li-ion battery pack is engineered to never overcharge itself, because the consequence of overcharging can be quite ... energetic. In fact, (genuine, not knock-off) Li-ion batteries have so many safeguards engineered into them that they will disable themselves on the slightest hint of failure, which makes them quite safe.
It is true that a Li-ion battery being kept at 100% charge ages slightly faster than one kept at a lower charge, and that's what the "overcharging" thing is all about. However it's a small effect that's not really worth worrying about.

twistero wrote:It is true that a Li-ion battery being kept at 100% charge ages slightly faster than one kept at a lower charge, and that's what the "overcharging" thing is all about. However it's a small effect that's not really worth worrying about.

Li-ion cells start to lose permanent full charge capacity as soon as they are manufactured, and this is accelerated by heat and high states of charge. For example... at 100% charge and a room temperature of 25C, expect to lose roughly 20% capacity over the course of a year. At 60% charge and the same temperature, that amount drops to 4%. On the other hand, at 100% and 60C (think hot car in the sun - NOT a temperature you want your Li batteries to reach) you'll lose 40% of that in 3 months.

With this information I set 40/70% charge thresholds in the 6-cell of my T61p, stored at about 25-30C. When I received it, its full capacity was about 54 Wh. 7-1/2 years later, its full capacity is about 70% of what it was new - with over 200 cycles.

How exactly does one "discharge" a laptop battery to 0%?

How exactly does one "discharge" a laptop battery to 0%?

Lenovo Power Manager has the "Battery Gauge Reset" which performs a full charge, then a full discharge, and finally another full charge on the battery. You can cancel the Reset at any time, so do this when the charge indicator is at 0%