Review of the HP 90W Auto/Air/AC Smart-pin Adapter

Hi guys. Ok, so here is a small review for this really neat charger some of you might be considering. I bought one of these last week. I plugged it into my Pavilion dv7-4083cl. One of the great features of this charger is that it has a button to charger the laptop battery, or if you choose not to charge it, just don't press the button. This is great on an airplane where you are not allowed to charge your battery, but can run off their power supply, no problem.

Well, after plugging it in, and not pressing the charge button, every few minutes I noticed that my laptop battery had increases in charge. tried to press button, and it charged almost as fast as if I had not pressed the button. Not good right? I ended up returning it, and today I received a new one. Following are some brief results.

Charger without pressing charge button

@4:47PM battery @ 82%
@5:07PM battery @ 83%
@5:19PM battery @ 84%

Charger with pressed charge button

@5:21PM battery @ 84%
@5:23PM battery @ 85%
@5:25PM battery @ 86%
@5:26PM battery @ 87%
@5:33PM battery @ 91%

As you can see, without trying to charge the batter, in about 32 minutes, the battery only went up 2% in power. Not bad, considering my first charger was giving my battery lots of juice every minute or so....

When charging, at about 12 minutes time, the charger gave my battery a boost of 7% power. I'd say I'm pretty happy about it.

The Good: 1. Looks well built. Has strong rubber underneath and all on the sides of the charger so you can have it sit on the side. Sturdy, and won't move and slide around, love it.

2. Extra adapter cord for older laptops with smaller connection inputs.

3. Two extra fuses. Hmm, not sure if this really is a good thing or not. I had no idea they were fuses until four calls to HP...they need better training. Anyway, so the fuses, where do they go, who knows, lol. The charger is very secure, I see no screws. So either you take it to someone who will take the rubber off or send it back to HP, so not really sure how the fuses will help us. If anyone can figure it out, please share your ideas here, thanks.

Than Bad: 1. Yes, as some of you might have read....its HEAVY!!!! Well, let me not scare you people, but yes, its a bit on the heavy side. Some think its 3 times as heavy compared to the standard charger.

The only thing I recommend is whoever buys this, make sure to test the charger without pressing the charge button then with. Because my first one was defective and charged just as fast as if it were pressed. Hope to hear from you guys. Peace.


KJ

 

That sucks that it continues to charge even without the button pressed. I was hoping to use it to go off AC power while maintaining a mid level charge on the battery so I didn't have to remove it from the laptop in order to preserve battery life.

I'm not sure whether I'd try to brave the horrors of HP support to fight them on this point as it will probably be a pretty good adapter to have for car/plane usage.

For anyone interested, I got it with the following discounts:

$32.50 Quick-ship instant rebate (this was the standard discount on the web page at the time of order)
$25.00 Coupon SVMB39487 (This is a $25 off of $125+ coupon which strangely works due to the original $129.99 price ignoring the other discount)

 

WickedYeti you rock!!! This community is amazing, wish I knew about notebookreview.com, ahha, anyway, I used your coupon code not more than 5 minutes ago...but before I did....I called HP to place a return on the the new one I have. Yes, true, it does not charge as fast as the first one on no charge mode, but whatever.... the point is you just saved me almost a nice cool $20.00 Originally I paid $97.25 with tax. Now I only paid $77.57 with tax. No more retail without discounts and coupons for me. Sweet.

I look forward to your review of this still amazing charger soon. I will let you know when I get mine. Also one more note.... not sure if it should matter...but I also purchased the HP USB TV Tuner which I love. The item came in a brown box with the box inside a nice colored box with the item pic on it as if you went to Best Buy..... the 90W adapter comes just in the brown box without a nice color cover, so it feels like someone is giving you a refurbished item. Also the second adapter came with the cord not even tied, so it makes it feel as if it was used. Anyway, I'd love to know if yours came with a decent box as if you went to Best Buy or another retailer to buy it....no decent store is going to sell you a new item just in a brown plain box with no graphics on the outside. Just my 2 cents.

KJ

 

...why would you not be allowed to charge your battery on an airplane, but you would be allowed to run your laptop?

Your numbers are pretty much useless because batteries slow down their charging as they get closer to full. If you wanted a useful comparison you'd have the battery at, say, 50%, and then time how long it took to get to 75% with the button pressed, then drain the battery back to 50% and time how long it takes to get to 75% without it pressed.

What I'm guessing is that you have to have some kind of driver or something on your laptop to respond to the button presses, because the charger itself has no control over how the battery is charged. It HAS to be something controlled by the laptop. What it may also do is just enable/disable the "quick charge" function of the machine.

 

Pitabred first let me say, love the user name, lol Goes great with Falafel.

As to your test suggestion, I think that is brilliant. As soon as I get the new charger, which is this Friday the 26th of November, I will run that test and give you guys the results.

As to your airplane question. They say it could ruin the airplane instrumentation..lol yeah right? I doubt it, but hey, I'm no expert. So charging is not ok...maybe the fluctuations in charging a battery causes mishaps on a plane, but just straight power supply to the laptop is ok? If someone is a techie and knows the real answer I'd love to know.

KJ

 

I'm with Pitabred - the laptop hardware controls the charging and it can't be done by a button on the power adapter. But...

The one scenario I can see is if the adapter is only supplying enough power to run the laptop. In this case, the battery wouldn't get charged. But, how they could manage that I don't know. I could see the button changing from supplying say 60W to 90W (those random numbers picked from head). If the lower power is enough to run the laptop, the battery won't get charged. This would also explain why the battery did get some charge as the exact amount of power the laptop uses varies with what is going on so a little may be available for charging.

I had a search for details, and the datasheet says "Smart-pin technology works with the notebook to optimise power consumption". That suggests there is an extra connection between the laptop and the adapter that somehow communicates the needed power. My bet is that the button switches this off and the adapter works at full power.

 

There must be something special about that "smart-pin technology" because as I understood it, a lithium ion charger is just a constant-voltage power source with a limit on max current. The battery is where the logic circuitry is that regulates how fast it charges and when it stops charging. Battery also contains safety measures to stop it if it gets hot or discharges too quickly. In contrast, the laptop itself doesn't really have much real logic in it for the battery, just a voltage meter that gives it an idea of what the battery is up to. The way a battery knows to charge or not is whether it is given a high enough voltage to permit charging (charge voltage is higher than what a battery generally outputs to allow it to absorb additional charge).

I can confirm with a multimeter that this adapter provides approximately 15 volts by default and with the charge button pressed it goes to more like 19.3 volts. I think it is THIS difference that is supposed to change whether it charges or not.

An interesting note is that the plug is a hollow cylinder shape where the outside surface is ground, the inner surface is the 19v (i happened to do this test in the 19v mode) and there is a center pin that also reads 19v. However, the inner surface reads around 19.7v and settles down to 19.3 after a few seconds and the center pin starts at 19v and settles upward to 19.3 after a few seconds. They seem to be the same voltage but they behave slightly different which makes me think this has something to do with the "smart-pin". The adapter they provide for older laptops seems to omit the center pin (i guess it was from before smart pin was invented?)

As all I have is the adapter right now (Envy 17 3D is hopelessly delayed), I'll have to defer to one of you or until my laptop comes in to test the voltage output on a normal charger or test for the presence of the "smart pin".

Also, to Killa Joe, mine also came in the fairly nondescript brown box but I don't think that's all that unusual for this sort of thing which I consider to be an OEM part. Also, did the laptop you tested on use the center pin or was it an older model?

Edit: I did an additional check with the adapter unplugged from wall and confirmed that the center pin and the inner surface conductor are not the same though they both output near the same voltage. There is approximately .293 Mega-Ohm load between the two. The numbers themselves don't mean a lot since they could change once the circuit is powered but it is enough to know that they are distinct for whatever reason in the charger circuitry. I can't find any real info on the internet as to how exactly this "smart-pin" works.

 

Thanks for confirming the "brown" box issue. Also, once again, thanks for saving money with your coupon code.
If you mean by "center" pin being the standard one attached to the charger, than yes. The model I tested it on is fairly recent, the dv7 which as mentioned will go back to Costco as soon as my Envy 17 3D gets here. Again, I'll do the 50% to 75% test on the OEM charger as well as the Air/AC/Car adapter with the button pressed and not pressed.

KJ

 

Just see this post and want to chip in my understanding about the charge/non-charge mode.

First of all, the most dangerous scenario of using laptop on airplanes is to have the Li-ion battery burst into flames. It is caused by the overcharge on the battery.

HP is actually the only one I know currently put up some warning on its website telling people it is not recommended to use laptop on airplanes. It is also the only one who implements a charge / non-charge button on its combo power adapter.

The charge / non-charge mode can be switch back-and-forth by pushing the button on the adapter. In the charge mode (non-charge mode), a 19.5V (15V) output will be deliver into the laptop. There is a circuitry inside the laptop to sense the input voltage. If the input voltage is 15V, the laptop will stop charging the battery. If it is 19.5V, it will do the opposite.

The default condition of the button is on the non-charge mode. I guess this is another way for HP to dodge the bullet if something goes wrong. It will be the user's decision to activate the charge mode.

However, there are more and more airlines equip the empower AC solution on the planes. I have not seen the charge / non-charge mode button migrates into the HP AC adapters. People can use AC adapters to power and charge the HP laptops on those planes. It kind of defeats the purpose of implementing that button on the combo adapter...