Lower ampere rating charger usage

[sman]

Hi,

I have stopped using Windows and on 'Live-cd' use only. The problem now is my laptop charger of Acer aspire 4736z is neither charging battery nor working direct w/o battery. 

The charger is a 19v, 3.42A 65w one and now i'm making do with a 40w 19v, 2.1A charger for direct use.. (w/o battery) . The charger which i'm using is for Acer One..

Though the working is fine, is it still ok to use the lower rating charger?

tks.

[Android8888]

Hello sman.

As long as the voltage value of the charger you are using is equal to the voltage value of the original charger (19 V.), and it looks like it is, then there will be no problem for the computer in using the lower rating charger.

However, being the value of the current that this charger provides, lower than the value of the current of the original charger, then two situations may occur:
1. If you use the battery with the lower rating charger, the battery will take longer to load than it would take if it were loaded with the original charger.
2. The current value (3.42A or 2.1A) can be interpreted as the maximum capacity that any charger has to supply certain equipment. For instance, if the computer requires 3A. then the lower rating charger will not have this capability, it may overheat and overload, however it is very likely to have a thermal fuse and enter in protection mode and switch off.

The voltage value is the main concern that you must have in your mind. The voltage value can never be different from the value for which the computer's power supply was designed to. This is a main rule.

Despite the lower rating charger is working well and should not cause any problems to your computer, it is my opinion that the solution that will offer you better guarantee will be to try using a charger with the same features as the original charger.

Cheers,

Rui

[sman]

Tks @Android8888, it puts me at rest.. With standby charger it is only direct power mode with battery removed and no charging involved. 

I'm still undecided to go for replacement charger, since would like to come clear with any problems with system from preventing charger's function.. It is a sudden development, and at times just before loading 'boot manager' just goes off.. 

I will have a word with service people and go for replacement.. tks once again..

[sman]

And moreover, tried charging battery with the standby lower charger but failed.. also an oddity which is not clear..Here must mention, this standby charger was used in the past in place of original and did charge the battery, if i remember right, but fails now, which is odd. could there be any reason for this? tks again..

[sman]

On googling, I find low current charging will only increase charge time, more time to charge , that's it but will still charge.. But in my case, the problem is the standby charger (low current one) is unable to charge and gives me goose bumps as to what is wrong then and may have to get service support to check system for any faults? Meanwhile, would help to have opinion from people on the know as to what could be wrong? tks..

[David H. Lipman]

That's correct.  a 65 watt power supply will take longer to charge than if you used a 90 watt power supply.  A concern though is periphery.  If you have multiple devices on USB, and you are not using a USB powered HUB, then a lower wattage power supply may be insufficient for the load.  The other concern is only for enterprise systems where a notebook may use a docking station.  Then the power supply required has to be sufficient for both the notebook and the docking station when the notebook is docked.  Another concern is that a lower wattage power supply may run hotter because the notebook is drawing close to its peak power rating.

A notebook without a battery can get away with a lower power rating power supply such as a 40 watt vs a 65 watt.  The 25watt difference is needed to charge the battery. 

Most notebook BIOS will tell you if the amount of power being supplied is insufficient.  You will see a warning message during the Power On Self-Test ( POST ).

Most retail notebooks use 65 watt power supplies and there are after-market suppliers and some "universal" power supply vendors.

[sman]

tks @David H. Lipman the problem is why the battery is not getting charged at all, and it's now only 'live-cd' use and very little RAM footprint unlike windows.. and morover though it's a 3Gb RAM (2 + 1), due to some loose fitment in RAM board, only 2Gb only available (1gb never comes into picture), and due to RAM limitations no.of web pages/browser tab that can be opened is limited if try to open more, get chrome 'Snap' alert.. what the pont is RAM Usage is also less not much of power drain involved.. And when the same 40W charger did charge the batteries in recent past, why it is not so now is puzzling..could there be any problem with system? tks again..

[sman]

In fact, under linux, it shows only 1GB RAM (maybe 2gb piece is not in proper fitment).. maybe it is the reason why i find limitations in no of open browser tabs.. so Power reqt shd be even less now and why then the charger is unable to charge the battery? I'm completely at sea as to what could be wrong? need help.. tks..

[David H. Lipman]

If the battery fails to charge, it has failed and it should be replaced.    It also sounds like mis-matched RAM.  I suggest 2 x 2GB modules that are the same speed ( such as PC2-6400 ).

Newegg - 9-cell ACER Aspire 4736Z Laptop Battery

[sman]

@David H. Lipman the problem is not with battery, but with charger (65w charger is neither charging or in standalone direct power supply sans battery and the standby 40w is also not charging but working in direct power mode sans battery) .. so the question is why the 40w charger is unable to charge the battery and battery seems to be fine with 70% charge? any clue what could be wrong? tks.

[David H. Lipman]

The power supply is just that.  It supplies power.  The circuitry for charging the battery is embedded in the notebook's motherboard.

I have managed hundreds of notebooks and would buy Dell batteries by the case.  I have dealt with recalls and numerous battery failures.  None had a problem charging a good battery.  The fault was always the battery itself.  In fact, a Dell Latitude NB would have a 3yr warranty but the battery was always only 1yr.

Replace the battery.  It is only ~$20.⁰⁰.

[sman]

@David H. Lipman if the battery charger is power source and charges in tandem with motherboard internals, why 65w ch..arger is faiikng as power source too?  only 40w is able to function as power source and why not 65w one? this is the dilemma.. can there be other problems? tks..

[sman]

I think i should check 1.whether 65w charger is able to work in Acer ONE (here too I hope using a higher current rating charger ie.3.42A for a 2.1A system, is ok?) 2. check with any other spare (probably old battery) battery as to whether it is charging with 65w & 40w one's.. I think this should give some clarity.. any views? tks..

[David H. Lipman]

If you have access to another battery, try it.  But do so with a 65W power supply.

[sman]

@David H. Lipman My worst fears seem to be coming true and problem definitely with 65w charger and in charging circuitry in 4736z system (unless batteries r ruled faulty with other similar systems)..

The reasoning, 40w charger perfect working in acer ONE and only charging problem in 4736z (tried with another 65w old battery which was literally on residual 0 charge & only 17% full charge holding capacity, here too charging failed).. While the 65w charger is problemmatic in both Acer ONE & 4736z systems.. so, unless the 65w batteries (running & old) are faulty, the 65w charger & 4736z charging circuitry are likely culprits.. any views? tks..

[David H. Lipman]

This Acer NB has Windows Vista 32bit and is a Duel-Core system ?

 

[sman]

@David H. Lipman I think you are referring to 4736z system.. It's dual core T4400 2.20 Ghz , and came with Win 7..

[sman]

The 65w running battery is more than 18 months old (was purchased in Sep'2015) with full holding capacity now at 65% ..(can last more than an hour) so has been working well only.. In fact, the 65w charger used to remain hot (the cgarger is also now a year old or so), and which I kept ignoring and may be this the reason for the present problems.. and both battery & charger are compatible make's not original, so could this also be cause of problem? tks..

[David H. Lipman]

I stand on what I have already written.

I take it the Acer was upgraded or had Win7 installed as it is my understanding that the Acer 4736z  came stock with Vista. 

I'm glad your are making use of this platform with the Ubuntu OS.  That makes it work worth installing 2 x 2GB, PC2-6400, RAM modules and buying a $20.⁰⁰ battery.

Edited March 3, 2017 by David H. Lipman
Verbiage correction

[sman]

It came with Win 7 pre-loaded and yes now into Chromixium (now renamed as Cublinux) USB boot and stopped using Windows, HDD due to my apprehensions with Windows & in-turn HDD.. Tks to your views @David H. Lipman.. Unfortunately the service unit head is tied up with some personal issues and un-accessible, which is holding in taking the final call .. anyway, will keep posted on developments and tks once again..

[sman]

The problem is with 65w charger only as working is fine when checked with another Acer charger at service centre (battery is charging and also working in direct power mode w/o battery).. Thank god, no problem with system internals but it was a shocker when Service audit revealed that in the last service, the 1GB RAM piece was never put back and no wonder system was having hiccups under 2Gb RAM working.. Atleast service people have now assured to make good the missing piece and sought some time to trace the missing piece or suitable replacement.. So, the charger replacement is on hold till then.. Hope, issues will be amicably resolved.. One thing which is still unclear as to why the 40w charger is unable to charge the 65w battery? A mystery indeed.. tks @David H. Lipman and @Android8888 for your views..

[David H. Lipman]

3 hours ago, sman said:

One thing which is still unclear as to why the 40w charger is unable to charge the 65w battery?  

No, it is not, as I previously stated...

On 3/2/2017 at 4:10 PM, David H. Lipman said:

A notebook without a battery can get away with a lower power rating power supply such as a 40 watt vs a 65 watt.  The 25watt difference is needed to charge the battery.

 

 

[sman]

The niggling doubt is due to past working with 40w charger in the same scenario when as far as I remember, it did charge the 65w battery and why not now? anyway, 'All is well that ends well'..tks @David H. Lipman All my worries r now abt getting that 1gb RAM back and get on with the replacement charger.., hope service people honor their words and carry out the service as committed, fast.. Till then, it will be testing times. 

[David H. Lipman]

What is the module ?

• PC2-4200
• PC2-5300
• PC2-6400

I still strongly suggest 2 x 2GB, PC2-6400, modules and a new battery.

[sman]

@David H. LipmanThe same 40w charger, which is there since the time of purchase of Acer One for last 10 yrs, (it's battery  & charger hv not been replaced since purchase).. 4736z was purchased after that and last time the 40w charger was tried for 4736z was nearly 4-5 yrs back (nearly after it's warranty when it's charger gave problems, probably connecting cable break bet charger & laptop).. so it is why,  when 65w battery charging with 40w charger was possible then, why not now ? peculiar scenario.. but not worth losing sleep over it now, as the service committments to move on is topmost than this odditity..