How to get the new 20v power plug tip?

[bradtem]

As most know, ?60 series Thinkpads use a 20v adapter and a whole new plug. I have an external battery for laptops which generates 16v or 19v. I would guess (unless somebody reports otherwise) that the new pads will be able to run on 19v instead of 20v, and if so, all I need is some way to adapt any other laptop plug, including the old thinkpad one, to the new tip.

So does anybody have a source for these new plugs, or better still, an adapter that can convert from an old standard 16v plug to the new one? (My battery happens to use the old plug as its standard output and came with a variety of adapters, but not this one.)

Or if I can just buy the tip, I can wire an adapter. Does this tip have a standardized name or part number?

When just running the thinkpad draws under an amp, so the battery should be fine with it. Don't know if it can deliver the full 4.5 amps that a power supply can do in theory, but don't think it has to.

Admin Edit: This is specifically a question forum so please stick to the topic area. It is not a place for repeating old, and tired, whinges... which have been deleted!

[slagmi]

Yes, I agree it will most likely run.

Running long term, charging batteries fully, those are different questions. But manageable.

Measure the tip. It's not an uncommon dimension.

Ebay, Dalco, Monoprice, Radio Shack, Fry's, et. al..

Consider I=V/R and thermals.

[bradtem]

Yes, I already considered that. It's not a very common dimension. If you know the part number or type that would be very helpful, perhaps a link to a specific web page or auction?

I read it as about 10mm OD, 8mm ID and a quite small pin (a bit hard to measure.) That's not any radio shack plug on their web site, it's not EIJA type 5. I have heard rumours of an EIJA type 6 but don't see much about it on the web, is that what it is?

[bradtem]

According to specs on adapters I see, it is 7.9mm outer diameter, 5.5mm inner diameter with central pin (size unsure, around 1mm or less.)

Searches do not readily discover plugs of this size, if it's a standard size it's a new one, not noted in various wikipedia articles.

The usual design of such laptop chargers (this is a 10.8v battery) would charge the battery with a few volts over 10.8, but not 20, which suggests a buck converter would drop down a variety of input voltages to the needed voltage, which would suggest it should run fine on 19. Will let you know once I find a plug or adapter.

[RealBlackStuff]

Kensington make an adapter which uses the N29 tip.
According to this blog, the above adapter does NOT work on the author's T61 and the N29 tip is a poor fit

[bradtem]

While I do plan to get the N29 tip, that's for my Kensington power supply only. I could buy a second one and try to do something from it, but that seems a strange way to do things.

I just want the plug, so I can connect it to a different adapter that goes into my 9 hour battery. Since the 9 hour battery uses old-style thinkpad jack on it, a cable with one old style thinkpad plug on one end and a new style plug on the other end would do the job, or an adapter with a female old-style thinkpad jack and a new style male plug would also do the job (since the battery's normal cable is a male-male of the old 5.5mm plug.)

But if the N29 is not a good fit, that's probably not what I want to buy and destroy. I guess I could buy an N29, and try to find a pigtail kensington 5-conductor plug, since 2 of those pins do go to the power plug, the others go to resistors which tell the kensington how much voltage to provide, as far as I can tell.

[andrzej]

Lenovo gray 20V tip dimersions: OD-8.0mm & IO-5.5mm & L-11.6mm (with 4.0mm shorter pin)
Lenovo 20V Tip for ThinkPad 6x Series: R,T, X (also s or t), Z and Lenovo C, N, V Series (41R4344) Price: $9.95
http://www5.pc.ibm.com/europe/products. ... enDocument

41R4344 at shop.lenovo.com

Targus Tip #S31-90W http://www.targus.com/us/product_details.asp?sku=APTS31 Price:$14.99
Targus Tip #31A-70W http://www.targus.com/us/product_details.asp?sku=APT31 Price:$14.99
Kensington N29 SmartTip pack Model number: 20048 http://us.kensington.com/html/10442.html Price: $9.99

Moderator edit: Shortened URL to prevent horizontal scrolling

[bradtem]

Though a touch overpriced, this is presumably what I would be looking for to solder up a cable.

In particular the part number from Lenovo is 41R4344 but since they do free shipping, this may be the simplest way to get it for the list price.

As for the Kensington N29, I have heard other reports that it does work, so that blogger had a bad experience, but the tip being too long is presumably trouble, I'll find out.

[bill bolton]

Though a touch overpriced, this is presumably what I would be looking for to solder up a cable.

No, its a tip for the Lenovo 90W travel power supply, similar in nature to a Targus or Kensington tip.

Its not a solderable connector part.

Cheers,

Bill B.

[bradtem]

Now of course anything can be soldered to if you have a mind to it, but this may very well not be ideal for that. So I'll repeat the call to see if anybody has a source of them. Don't see anyhing with a 7.9mm OD (or anything that large) at places like digikey and mouser, certainly not at radio shack.

But somebody must be sourcing them to build all those clone power supplies. Actually, I have seen the supplies as low as $17 so it might be the simplest thing to just get one, cut its cord and wire a jack/plug in the cord so that I have both an extra power supply (to be marked carefully!) and an adapter.

Kinda crazy to buy a power supply just to get a pigtail, though! I would just have to find a cheap inline pair of jack/plug for the old 5.5mm/2.5mm thinkpad plug. And mark to never plug an old TP into the 20v supply.

[hellosailor]

There's another option, which I'm considering.

Cut the plug off the stock OEM power supply. That's right, cut it right off.

Now install a set of Anderson PowerPoles on the wires instead of splicing them back together.

www.powerwerx.com/anderson-powerpoles-accessories

Powerpoles are available from many sources, and in ham radio circles they have become "the" standard 12V connection, using the standard red/black pairs. You'll want to use a different set for the 20V connection, simply to make sure no one confuses it with a 12V supply.

Then you can take any device or supply you need, as long as it is electrically compatible, slap a pair of Powerpole connections on it, and feed the Thinkpad from a STANDARD connection.

I can't even figure out what the proper industry terminology is for the power connection that Lenovo uses. Something like an "extremely thin center pin reverse gender coaxial power plug" but there must be another way to refer to it, since "coaxial power plugs" usually have a female center, with the center pin in the socket.

I'd also like to find out why we're dealing with 20V supplies, when there's almost certainly nothing in the computer that really needs or uses anything over 12V (which would charge fine at slightly higher).

[bradtem]

I presume it's just so that they can get more power (90w) into the computers at the same current (4.5 amps.) They probably chose a connector that can do even more current in the future.

It's often called a "barrel" connector or "coaxial dc power" It is the same format as the EIAJ #5 connector, but much wider and able to handle more voltage and current. EIAJ are the new standard, but as far as I have been able to tell the Lenovo connector does not follow any standard I have seen.

And yes, at this point, buying an $17 OEM power supply and doing something like this may be the only easy course until somebody finds a source of the plugs.

[hellosailor]

"I presume it's just so that they can get more power (90w) into the computers at the same current (4.5 amps.)"

The only problem with that, is that it would require more components in the laptop, to reduce the excess voltage back down to what the components need--which is typically only 5 VDC. There are power losses and economic expenses and real estate (size) losses involved with that, as opposed to simply using a different connector. Consider that a standard 120VAC "cheater cord" can handle 10-15 amps at 125VDC with no problem.

Sometimes I feel like a dog using an elevator: I know it WORKS, I just have no idea how it is getting the job done. I supposed we'd have to take hostages to get an answer from IBM, or Lenovo. (Road trip!<G>)

[bradtem]

You are correct that internally the laptop uses lower voltages like 5 volts for the hard drives and even less for the CPU.

However, the chips that convert the voltage down don't actually differ a great deal on whether they work with 16 volts or 20 volts. The chips sold today quite commonly will take anything from 18 to 36 volts, for example, or any number of other ranges.

They will be slightly more efficient at certain tuned voltages, but only slightly.

However, to charge a 10.8 volt battery, you do need to put in a few more volts than that, so there is a certain minimum. You can convert up but it's easier to get a chip that just converts down, and usually you like a few volts of gap between input and output.

Lenovo has said it was that they needed more power -- implicitly at the same current. The old plug just wasn't enough for 90 watts.

However, they still made a big mistake. As I outline in my blog post at http://ideas.4brad.com/laptops-could-ge ... ays-stupid
they could have chosen a connector which was backwards compatible -- ie. the new plugs would not plug into old jacks, but the old plugs would plug into new jacks, and accepted 16 volts, and when noticing it, just disabled certain functions when the battery was low.

(Such functions could include charge and run at the same time, or even charge at all if desperate, or high CPU clocks etc.)

Apple computer did this years ago on older notebooks, so Lenovo has less of an excuse for not thinking of this. Apple had a slightly easier time because they originally had a multi-conductor power plug, but Lenovo could still have pulled it off.

However, we still seek a source of the plugs. I have not tried it yet, but it's entirely possible that this will work even without deliberate design, just because the standard power chips often do this. By "this" I mean powering a new thinkpad with 16.6 volts from an old supply. However, while undervoltage rarely will damage things, don't sue me if it does.

[hellosailor]

Brad-
DC charging today is more than chips and volts, the old rules have been thrown out and "intelligent" charging systems can gain an easy 10% efficiency. Granted these are lithium-based batteries and that makes them start out way more critical than lead and NiMh ones...but designers are now using charging algorithms that examine the battery voltage/impedance and temperature, and then apply a precise amount of voltage and amperage based on a table lookup. No more "two stage" or "three stage" charging, "float" and "bulk charging" just means obsolete technology.
From what I've seen (in MPPT controllers used with solar arrays and DC storage) the new paradigm is to lead the battery voltage with a very small amount, while applying as much amperage as you can without doing damage. As the voltage rises, you keep leading it (sometimes by 1/4-1/2 volt in a 12v system) and you pump im amperage instead.
I say "instead" because the MPPT systems convert input power into output power, and being digital designs (with coils aka transformers) they can change the voltage/amperage ratio at any instant, while maintaining full power.
Are the Lenovo charing systems that smart? Dunno, but I suspect so. My Compaq, which was a DEC design, broke the batteries (12) in the pack into serial/parallel arrays and actually used sensing leads to each pair of cells to monitor and charge them separately--not as a pack! That's decade-old laptop design.

So what they do now, and why they choose to do it, is a total mystery to me. I'm pretty certain that it is NOT simply a matter of using the old fashioned 78xx or 79xx 3-pin regulator chips, the way things were once done. These days, those are considered cheap, crude, and inefficient.

To charge at 10.8 volt battery with the typical 15% charging losses, you'd still only need 12.5 volts. It would be very easy to use a nominal 12v supply, so that car/boat/plane adapters were largely unnecessary. I've got to suspect that they are doing SOMEthing else with the excess eight volts, but I can't see wasting room (and making heat) inside the computer by downconverting that without any real need. Carrying the total wattage (90, even 150) and amperage 9even 10 amps) with a different plug would be trivial, compared to the costs of shedding excess voltage in the computer.

It may have been a mistake, or someone's cousin selling proprietary plugs <G>, but there's got to be some reason for this peculiar 20V arrangement and "more power" doesn't make it.

I'm just not inclined to tear down my laptop to try to figure out what's happening in there.<G> Surely there's someone among us who engineering contacts. Or willing to take that road trip, and hostages?<G>

[bradtem]

The issue is the desire for 90 watts. Take Lenovo at their word that they need 90 watts (if not in your particular laptop, at least in some of the laptops in the line) and if you further accept that while the old plugs can probably handle 5.6 amps, they probably are not rated for that much current, and vendors have to stick to ratings or get sued.

And there's no way to deliver 90 watts at 16 volts without having 5.6 amps, I'm pretty sure.

So what's inside will indeed be efficiently changed by modern buck and boost converter chips. (The cheaper of these chips do tend to need a modest voltage gap between input and output, so it's actually more work to put 12 volts into the battery from a 12 volt source through the chip. You would need a different chip or a circuit to temporarily directly wire the voltage which I doubt they would want to do.)

Though yes, I would like them to use better chips that can both buck and boost on the same circuit, so you can run on any voltage at all if the current is there.

Do they really need 90 watts? My thinkpad doesn't draw close to 90 watts. However, I expect they considered the question of:

The largest, 7 cell battery, completely empty and charging

The fastest processor they sell, at full speed on both cores

All USB ports taking their full 2.5 watts (5 to 7.5w total)

The optical and hard drives spinning

The screen on full bright

And decided 70 watts would not cut it or get overloaded. Plus you need a little tolerance, you don't want to run at the edge.

So I believe that the above, in the most heavily powered unit in the line, needed more than 70. Note this might not be your X61, but they're not going to do one power supply for an X61 and another for a T61, much as you might like 'em to.

However, as I said, they could have designed it, like the Mac was designed to say, "How much power do I have available? Ok, in that case I will manage what power I use."

Which could mean, for example, noticing when you're on a 16 volt (70 watt) supply in the above situation and telling the user, "Sorry, you can't run the computer and charge the battery at the same time on this power supply until you get the battery to 50%"

We would all have been more than happy with that.[/list][/list]

[hellosailor]

Maybe I'm not making this clear.

I have no disagreement with 90 watts, there are laptops that have 140+ watt supplies.

BUT THERE IS NO NEED FOR 20 VOLTS in a conventional laptop. And no need to supply and convert that kind of excess voltage simply in order to push amps into it at lower voltages, either.

At least, none that I can see, and while I'm not a BSEE I've done my share of power supply work.

Incidentally, on the USB ports the nominal rating of a USB port is five volts at not more than 400 or 500 milliamps (I don't recall which) so any one USB "master" is only a 2.5 Watt device--not five watts. Whether all the USB ports in the computer are tied to one 2.5W supply, or multiple USB masters are used, is a design choice.

Even with dumb cheap regulator chips, voltage drops in the chips, and charging losses to the battery--there's no need to use 20VDC to charge a 10.8VDC battery pack, unless something VERY unconventional is going on.

[bradtem]

Sorry, I think you're just wrong.

If you accept the need for 90 watts for all the things put together, and you accept that the plug is not rated for more than 4.5 amps, then yes, there is a need for 20 volts in the laptop. It's the laws of physics. You can't get 90 watts at 16 volts if you can only have 4.5 amps. It's just not possible.

This has nothing to do with voltages inside the laptop which are indeed lower.

It's just a question of how much power the laptop can peak at, and how much current you are comfortable with putting through your wires and connectors. That is what decides the voltage you need.

You can have a lower voltage if you are willing to have more current, but more current means thicker wires, better connectors and higher risks. You can have lower voltage if you have a lower maximum power. But you can't change these rules.

And yes, USB is 2.5 watts. 2 USBs are 5 watts, 3 are 7.5 watts maximum. Other peripherals inside (bluetooth, 802.11, card reader, card slot) will also factor in the max power calculation.

[hellosailor]

"And yes, USB is 2.5 watts. 2 USBs are 5 watts,"
No. Two USB bus masters are 5 watts. Two USB ports, driven by the same master, side by side on a case, are sharing the same total 2.5W and if you plug in too much stuff--usually you'll blow the one fuse that protects them both.
That's a design choice, and few designers would spend the money to put a separate master controller behind each USB socket on a computer.
Device Manager shows seven "Universal host Controller" USB devices in my computer--but if I open them to read the details, there are only two physical devices, which means the right-side USB port and the two left-side USB ports are probably on just two controllers. Possibly 500mW available to the right side, another 500mW split between the two on the left.
But looking further in the Device Manager is even more amusing, it shows seven (!) "USB Root Hub" devices, each with "500mW available" indicated in the power properties.
Perhaps there is a most unusual Intel controller in this machine, with seven fully available USB assets, only three of which have been brought to the outside of the case?!

That kind of stuff is why I say guessing won't tell us why or if 20V really serves any purpose--there's just no way to tell from the outside.

On the power plugs? Sorry, you are still missing the issue. The physical plug itself will have a maximum amp rating, sure. But I can give you a set of Andersen PowerPoles that will carry 45 Amps, and plug them into a laptop just fine. They'll take up more space, but so what? The form factor of the power plug doesn't matter, if it can't carry your power--you pick a different one! There's a common AC 2-line plug usually called a "cheater cord" that is used on eveyrthing from electric razors to television sets (where is also forces you to pull the power cord before you take off the back of the set), and I can assure you Lenovo engineers have seen and used them. Of course, that would be a bad choice here since eventualyl someone would plug 117VAC into the laptop.<G>

And when you pick a proprietary one, it is almost always--almost--because you want to make sure that everyone else has a hard time selling accessories for your product. It's that simple. Occassionally it is to make sure no one else plugs "the wrong thing" into your device but if the power supply has wide tolerances--that's not a likely issue.

I've got plenty of radio equipment running on PowerPoles and they work like gangbusters. Up to and including a thousand-watt power supply. A little bulkier? Yeah, but not much. The lenovo power plug is not "required" because of the 90 watts, it was chosen because Kensington and Igo and Taurus would have a hard time competing to sell power supplies. Or, because someone's nephew is making lots of money as the sole-source supplier of them.<G>

It really is that simple, this is not a matter of electronics and amps, it is anticompetitive marketing. Which is not unique to any one company.

[bradtem]

Nobody is going to use Andersens on a laptop, I suspect. Too large.

However, what they could use is beside the point. It's what they had, which was a 5.5mm OD, 2.5mm ID coaxial DC connector. For now, I am taking them at their word that this older connector was not able to handle 90 watts at 16.6 volts (5.4 amps) within full tolerances.

If that's true -- though they could be lying, I suppose -- then they had to come up with something new to do 90 watts. I do believe they could have done something backwards compatible so that old supplies would still drive new computers in a more limited fashion. We don't know all the parameters. I could be that there are some older thinkpads that would not handle a power supply that can give them 5.4 amps properly, drawing too much current rather than just causing the supply to shut down. It could be it's very hard to do a safe 5.4 amp variant of the 5.5/2.5 plug. I hope they considered that, they probably did.

They say that something of this nature made them decide they could not power the new units with the old specs. This means they needed a new plug. There are many ways they could have gone, though you can bet they will want it light and cheap. Maybe they wanted to stop aftermarket supplies but there seem to be plenty of them, so it didn't work.

Now once planning a new plug, you can use higher current, but by and large you don't want to. Lower current is just about always better, until the voltage gets so high you have risks of shock, arcing or insulation breakdown which you don't in this range of voltages. You want a very good reason to go with higher current. Once you no longer will be plug compatible, no good reason remains.

As I've said, I would have done it differently, by allowing the new thinkpads to run in a more limited way on 16 volts and providing an adpater or one-way compatible plug. They didn't, and that was a mistake. But I doubt that they felt they could have kept the old plug at higher current, and changed the plug just to sell more power supplies. That doesn't make much sense.

[bill bolton]

The lenovo power plug is not "required" because of the 90 watts, it was chosen because Kensington and Igo and Taurus would have a hard time competing to sell power supplies.

Since Kensington and Targus had the plug available fairly promptly after Lenovo started using it, that is clearly not the case.

Or, because someone's nephew is making lots of money as the sole-source supplier of them.

There are quite a few devices using similar (if not identical plugs) now a days, so this proposition also fails.

The bottom line is that Lenovo changed the plug because they changed the voltage. Niether the plug nor the voltage is ever likely to change back, so continuing to complain about it 18 months down the track is pointless.

I can't use the same size/type of tyres on my automobile today that I did on the automobile I had 10 years ago... the world changes!

Cheers,

Bill B.

[frankiepankie]

Sorry for kicking this old topic guys, but i was looking for the same (the new style power tip, so i can re-use my car dc-dc adapter that hasn't got the right tip)

I was looking all over the internet, found some tips to use with certain DC-DC adapters, but after a while i found this:
http://cgi.ebay.com/Power-Cord-Plug-for ... _964wt_939

And this:
http://www.bixnet.com/dccotipforib.html

The eBay looks like it has been ripped out of an genuine IBM / Lenovo charger, while the second one looks like a Chinese clone (which maybe would work fine too )