Life expectancy of laptop power adapter

[woolyhead 15]

I was told by the shop that just sold me a replacement HP power unit for my laptop that they "don't last long." Not a good recommendation is it. Anyway, how many hours use will they give, on average? I noticed that it gets quite hot sometimes and realised that the transistors inside the plastic box must be a lot hotter than the case so I'm thinking of knocking up a fan for cooling the outside of the box. It should make the unit last longer, don't you agree?

[Ghozer 112]

They are not designed to be left plugged in and switched on all the time..

 

if you are using a laptop via the adaptor, it's also advisable to remove the battery.

 

if you are not using the adaptor, unplug it, don't leave it plugged in and switched on when not in use...

 

when the battery is fully charged, unplug the adaptor from the laptop and the wall..

 

follow these, and there shouldn't ever be a need to replace it..

 

Should also help keep your laptop battery going for longer!

[Cyclone 10]

I've had my latest one for at least 5 years.

 

I've never had a power supply fail on me. Including ones that are left plugged in all the time.

[AlexAtkin 10]

I have had few adapters die, the ones that did were both 12V.

 

On the other hand, the 19V one from my old Pentium 4 laptop is still going strong.

 

If the replacement is not official and they are saying that, I would refuse it and go get an official one.

[martin6 10]

Had laptops for last 20 years at work, all left plugged in all the time. Never had problems, never replaced batteries. Had each one around 5 years. All HP. You can leave it plugged in as the charging circuit will shutdown or trickle charge to prolong battery life.

[AlexAtkin 10]

Leaving them trickle-charging is supposed to age the battery. It wrecked the one in the laptop I mentioned above within 6 months (annoying I didn't realise the battery was still under warranty at that point until AFTER).

 

That said, I have always thought it stupid that some people are more worried about prelonging the life of their battery over it actually being charged when they need it. I always keep my phone on charge when I am at home for that reason.

[martin6 10]

It looks like some do some don't have issues leaving laptops plugged in. Could it be that batches of batteries are not always made to the same specification and / or from different suppliers. Electronic equipment is very reliable nowadays but you always he's of someone's tv/pc/phone etc broken down after 12 months

[Cyclone 10]

Batteries I have seen die. Quite a few actually, all around the 4 to 5 year age mark. They just lose the ability to hold charge.

It was the PSU the OP asked about though.

[woolyhead 15]

I know that a fan wouldn't make the battery last longer but it could make the power unit last longer. My previous power unit had no fan and lasted six years so I was hoping that by cooling the new one, a genuine HP one by the way to go with the HP laptop, it might last even longer. Then I realised how old that would make my laptop if it did. To prove the point the laptop would have to last a very long time, far too long. But I want to make the fan unit just for fun. I'd like to have a go at repairing the old power unit. I've opened it up and the circuitry inside is old fashioned PCB and semiconductors plus a transformer. If I knew what type number each of the semiconductors was I could replace them. But instead of industry standard numbers they have special numbers put on just for the one manufacturer. I can't replace using such numbers. Has anyone any idea what circuitry and components are used in these units?

Edited August 21, 2015 by woolyhead

[allysum 10]

I'm surprised the semiconductors are specially numbered, the component you're more likely to have trouble with is the transformer which will be custom wound to the manufacturers specifications.

 

Anyway, power supplies are one of the most complicated electronic devices to deal with, not through structural complexity but just getting the thing to work as it should do. Engineers spend a long time getting power supplies right which is why many electronic devices manufacturers design their circuits to fit round the PSU rather than building a PSU to fit the device.

 

Ever bought something like an answerphone or an alarm clock where you can hear a faint whining from it? Chances are the other 200 units out of the same batch didn't have the whine but that one you ended up with had a single component in the PSU just 0.5% different in it's tolerances to the others.

 

Point I'm trying to make is that messing with PSU's is not advised for a variety of reasons, all of which explain why most are either heat sealed up (laptop supply) or riveted together (ATX supplies for example). Also the same reason there are almost no PSU refurbishers around and a secondhand PSU should not be purchased from Ebay in case it's been messed around with on the inside.

 

If you're a determined tinkerer and know all the risks of dealing with capacitors and transformers then I might be able to help out with tracking down the right semi-C's.

Edited August 28, 2015 by allysum

[tzijlstra 11]

I've never had an issue with PSUs for any of my laptops, it is usually the battery that goes beforehand. I used to think it was due to the size of the things but even my MacBook Air charger, which is tiny, is behaving well.

[AlexAtkin 10]

Batteries I have seen die. Quite a few actually, all around the 4 to 5 year age mark. They just lose the ability to hold charge.

It was the PSU the OP asked about though.

 

That's not premature death though.

 

Lithium-Ion especially are only supposed to last a maximum of around 5 years, even if you carefully look after them. I believe the average though is 1-2 years before their capacity really deteriorates.

 

That's another reason (the main one being manufacturing quality) buying random replacement batteries can be a problem. As they start to wear out from the date of manufacture, even if they are never used. So can you end up buying a battery that is already failing.

 

---------- Post added 22-08-2015 at 05:00 ----------

 

Point I'm trying to make is that messing with PSU's is not advised for a variety of reasons, all of which explain why most are either heat sealed up (laptop supply) or riveted together (ATX supplies for example). Also the same reason there are almost no PSU refurbishers around and a secondhand PSU should not be purchased from Ebay in case it's been messed around with on the inside.

 

If you're a determined tinkerer and know all the risks of dealing with capacitors and transformers then I might be able to help out with tracking down the right semi-C's. PM me if I can help

 

The reason they are sealed is more to do with being double insulated and protecting their ass from being sued if someone gets electrocuted. That and wanting you to pay them for a replacement if it breaks rather than fixing it yourself.

 

It annoys me no end how pretty much everything these days has the "no user serviceable parts inside" notice. Which is clear BS in many cases where a HDTV PSU can be repaired/replaced, dry joins can be reflowed, etc.

 

Bearing in mind I suck at soldering and still have repaired a few routers with blown capacitors, although I usually avoid PSUs as they have a habit of being very cramped and a lot of capacitors, so can be hard to do.

 

I have never seen an ATX PSU sealed with anything but screws and they most certainly can be repaired. The biggest issue being that often when a PSU has gone bad its because it was a poor design to begin with.