Can I use a charger that provides the same voltage but a different amperage?

Chargers and power supplies come in a wide variety of configurations. Choosing the right one is important. I'll look at a few of the parameters.

I’d like to know if it is okay to use a different power charger for my netbook. Originally, the charger specs are 19v and 1.58A. This charger is not available anymore and I can only find a 19v and 2.15A. Can I use this as a replacement?


With a couple of caveats, of course.

Getting the right power supply – if it’s not made specifically for your particular model of computer – involves matching voltage, amperage, and polarity.

And each have different constraints.


Let’s start with the simplest.

The voltage output by your charger/power supply should match as closely as possible. In your case, you’ve got that covered: you had 19 volts before and your replacement candidate is also 19 volts.

When replacing an external charger for a battery-based device like a laptop or netbook, it’s important to get the right voltage. The device may work with voltages that are close, but often at the cost of shortening the lifespan of the batteries being recharged.

When replacing an external power supply, the same rule applies – except that you may be shortening the lifespan of the device by not getting the same voltage.

Or you may not.

Some devices are quite tolerant of voltage variations and will work just fine. Others, not so much.

Because there’s no easy way to know which category your device falls into, it’s best to simply get the right voltage from the start, if at all possible.


Many people are confused by amperage ratings and what they mean when it comes to power supplies and replacements.

One easy way to look at it is this:

  • Voltage is provided by (or pushed) by the power supply.
  • Amperage is taken by (or pulled) by the device being powered.

In other words, while the voltage is a constant and should match, the amperage is something that varies based on the devices need. Your computer will “pull” more amps when it’s working hard than when it’s not. The voltage will remain the same regardless.

The amperage rating of a power supply is the maximum number of amps that it’s able to provide if needed.

Thus, as long as you replace your power supply with one that is capable of providing as much or more amps than the previous supply, you’ll be fine.

If you replace the power supply for some reason with one that has a maximum amperage rating that is less than the previous and less than what your device actually requires, then you may end up with a burnt out or (at least) overheating power supply, and the device itself may not function, or may not do so well.


This one catches many people by surprise, especially when replacing simple or small power supplies with generic replacements.

Most power supplies provide DC (direct current) power via two wires labeled positive and negative. Polarity refers to which wire is which.

Just because the physical plug into your device matches doesn’t mean that the positive and negative connections are hooked up the right way. In fact, there’s often no real standard.

Particularly when it comes to popular circular power connectors, make sure that the expectations match: if the device expects the center connector to be positive and the outer ring to be negative, your power supply’s connector must match. If the device expects it the other way, the connectors must still match. There’s no getting around this.

Often, you’ll see some kind of indication on the power supply that will show which connector is negative or positive.

If you’re replacing a power supply that uses a custom connector used only by one manufacturer, then typically you don’t have to worry. Similarly, if the device is powered over a USB connector, that standardizes the connection, too.


In short, when replacing an external power supply or charger:

  • Make sure that the voltage matches as closely as possible.
  • Make sure that the new supply is rated to provide the same amperage or more.
  • Make sure that the connectors match, both in physical form and in polarity.


  1. Robert R

    Interesting analogy for volts vs amps. I’d always heard the water hose comparison, voltage is the water pressure, amperage is the amount of water flowing through the hose.

    • KDS

      Your water analogy is incomplete: voltage is the water pressure, and amperage is the SIZE of the hose. A small hose under a lot of pressure will get you wet; a huge hose, even under low pressure, can wash you away. But none of that has to do with the volts pushed to and amps drawn from a computer, really.

  2. David Price

    Very well said (sound electrical opinion) I agree completely. David (Australia).

  3. Dan

    Just be careful with some laptops. I know that with my Dell laptops, if the chip in the charger goes bad (the chip that tells the Dell laptop that this charger is the correct charger for the computer), it will no longer charge the battery, and the laptop will draw less power (or amps – but Amps times Volts gives you Watts – or power) – thus slower laptop. Their reasoning, is so you don’t plug a charger in that isn’t rated for your laptop and damage it, but it forces you to only buy the correct Dell chargers, and when that chip goes, even if the charger is working – you no longer can charge, and you have a slower system (even my USB ports wouldn’t produce the correct power output when the Dell isn’t able to read the charger’s chip.)

  4. Steven

    You mentioned “most” are DC currents. I think you should caveat that with most “U.S.” I may have missed it, but I didn’t see that mentioned.

    The output of most power supplies and chargers is DC world-wide. The input is typically AC world wide, but with voltages that differ depending on where you are.


  5. Mike

    Very good explanation. Two other problems arise, though. The TYPE of voltage. While most chargers are DC, some are AC or pulsating DC, which just will NOT work place of the correct one. AC chargers are usually represented by a tilde (~), and pulsating DC chargers are indicated by a solid line over a dotted line, kind of like highway dividers where there’s no passing in one direction.

    The other problem is size of the coaxial connector, and the combinations are nearly endless. There is the I.D. or Inside Diameter, which is what size the pin will fit into, and then there is the O.D. or Outside Diameter, which is the outside ring that plugs into the device to be charged.

    Nothing more frustrating than to spend $10 – $25 on a replacement charger and find that it doesn’t fit at all. And often, none of the adapter fittings work, either.

  6. Jim Cooper

    Dell Laptops have that center pin, I forget what the interface is called, but it makes it likely that other chargers won’t work. I bought a higher amp Dell charger to replace my busted one, and it works great, but I had a Dell parts expert guide me to the right choice

  7. Yeppers

    Leo, what are the voltage and amperage ratings of a USB 2.0 port on a PC? I’m looking to purchase a USB recharger that plugs into the wall for use with a MP3 player when traveling without a PC. Do the rules you list in the Summary section apply to a USB wall recharger? (By the way, does the voltage and amperage output for each USB port decrease when you are using more than one USB ports at the same time? And are the power ratings for a USB 3.0 port different from a USB 2.0 port?) Thanks…

    I believe that USB provides 5 volts at 0.5 amps maxium per connection (that’s often whil you’ll find some devices that connec to two USB ports, because they need more than 0.5 amps but less than 1.0). Remember what the article said: the voltage remains constant, and the amperage is dependant on the device’s needs, regardless how many are connected. USB wall chargers have to provide the same voltage (like the article said, it’s fixed), but some are capable of providing higher amperage for those devices that can use it.

  8. Andrew Keir

    Many people are confused by amperage ratings and what they mean when it comes to power supplies and replacements.
    One easy way to look at it is this:

    Voltage is provided by (or pushed) by the power supply.
    Amperage is taken by (or pulled) by the device being powered.”

    – facepalm –
    Oh Leo, you’re a great IT guy but not so hot at getting electronics across to beginners. I could agree with your definition of Voltage – the ‘push’ on the electrons that tries to make them move and make a current, but not your definition of Current. The load / laptop / whatever does NOT pull – it lets the current through; faster if the resistance is low, slower if it’s high. Current is how fast the electrons (that carry the charge) are moving.
    But I thoroughly agree with your working rules; get the voltage exactly right, and only substitute a higher current power pack where a lower current one used to be.
    And if you use a different size plug you’ll be sorreee…

    I stand by the analogy (or is is a metaphor?). Of course it’s not technically correct, analogies rarely are. But in terms of making the concepts usefully understandable to people who don’t care about Ohm’s law I think it works.

  9. Steve

    For Mr. Keir. I prefer to think of current as volumn and voltage as pressure. An example being a water pipe with a pressure/voltage of 10psi and a diameter(volumn)/current of 1 inch allows so much water through. Increase the volumn/current to 2 inches and it lets 4 times as much volumn through. aka available wattage. ( I think I got that right) Its been a long time….

  10. Peter Mackin

    Leo, I agree with your analogy re power supplies. However, your statement that voltage is constant is not correct. If you load up a power supply, you will have losses in the wire that connects the supply (wall wart) to the device. Engineers like to refer to this as I^2R (I squared R) losses. The losses increase a the square of the current so a doubling in load will more than quadruple the I^2R losses in the wire. These losses cause a voltage drop in the connecting wire so that the voltage seen at the load drops when the current increases.

    As you said, if you get a supply rated at the same voltage as the one being replaced and with a current rating at least equal to your device’s requirements you will be fine with respect to I^2R because these losses will already be accounted for in the design of the power supply. I just couldn’t resist picking a nit. :-)


    Yep. And for the audience and use for which this article is targeted that nit is just unnecessary distraction. :-) (My degree is actually Electrical Engineering, so I do have a clue about how complex this can get. However my audience isn’t nor should they need to be. Smile)

  11. Hilary

    This is a great and *necessary* question-and-answer. At the risk of seeming politically incorrect, it may be more helpful to female computer users than male. In 2007, my terrific but three-year-old Lenovo laptop was fried after a now defunct, major electronics dealer opened a Kensington “choose-your-AC-tip” package, stuck it into the power supply, and “told me” it was right. The laptop fried within a week, and I resignedly concluded that its age was the problem. Several months later, packing the otherwise new Kensington adapter set to sell, I read the Instructions that came with it. I also noticed that the little baggie that held the color tip I *should* have used was unopened. In short, I settled with the retailer’s insurance carrier on the eve of its bankruptcy. Otherwise, I would have been out not only an excellent machine, but the amount I paid for the tips. I’m making this comment to warn husbands with non-electronic-savvy wives not to allow any “expert” to tamper with equipment on the basis of the (stereotypical) assumption that because an “expert” is male, he knows all about electricity and how it works. (I hope I don’t offend anyone, but I have seen other cases where female computer users just assume that men understand all about electricity.)

  12. Allen

    Very good article and comments. No mention was made about Lithium Ion batteries and their associated chargers. The little bit of reading I did on the topic scared me away from exploring substitute chargers for Lithium Ion batteries. Was I being too cautious?

  13. packrtz

    I’m not sure your answer about current rating is truly “exact”. When you refer to replacing a charger with equal voltage with equal or greater current rating you are “sort of correct’ -BUT — the issue of current is a bit fuzzy. IF you want to run the device off the charger it MUST have a current rating equal #or greater# – however if you want to CHARGE a battery a lower current is permissable! The HIGHER the current rating of the CHARGER the faster the battery will charge.

  14. A. Orcan

    Chargers come in many qualities. A 19V charger with lower quality may have 21-22V when no current is drawn. However, a charger intended for brand A with 1.6 Amp will have about 19V at full charge and operation simultaneously. With the battery charged, it will have about 19.5-20.5V output fed to a laptop and the battery will continue charging at a negligible trickle rate. When a more powerful charger with 2.5 Amp rating is used, intended for laptop B, with higher power consumption, its output with the laptop A maybe as high as 20-21V with full current drawn and higher after charging finishes. This will cause a higher charge to a battery, even after it is completely full and shorten its life and may even cause an explosion. The chargers are PWM regulated, and ideally such problems would be avoided, but to keep costs down, regulation is not 100% and compromises against costs are made. Exceptionally good chargers are not common and these cost very high. At home, I use a variable Voltage and current supply to monitor and adjust charging curve against time to match aging characteristics of the battery. Travelling, I use chargers with a display and Voltage adjustment slider to prevent overcharging at high levels for my two laptops.

  15. Sara

    Hi Leo … I need some help out here …

    I have a Vaio laptop
    the original charger which is gone now has :
    19.5 V
    Input: 100-240 V ~1.6 A 50/60 Hz
    Output:19.5 V … 3.3 A

    No here is the new charger I got :
    19.5 V
    Input:100-240 V ~1.3 A (1,3A) 50-60Hz
    Output:19.5V(19.5v)…. 4.7A(4.7A)

    the Amperage in new one is less input but higher output !!! compared to the old one .which one counts?
    I am worried it burns my laptop …

    The original Model is VPCEA42EG E series
    The new one is for model VPCEB42EG E series

    I am confused by this input output thing … the original model is not available since am in Iran n there is sanction… Is it safe I use the new one ? or I should ask someone bring me the original model from another country?
    Dear Leo plz email me your response …


    It’s only the output amperage you care about. The new one can supply MORE, which is perfect.


  16. Mark J

    As long as the output voltage is the same and the output amperage is the same or higher you should be good to go.

  17. Cletus

    Your explanation is correct. However would still like to know whether an original charger supplied with a new laptop does charging such that the charging current decreases as the battery attains its full voltage. I have a sony fz series. The ac adapter has an output voltage of 19.5 volts, 3.9 amps. The battery is li ion 11.1 volts, 4800 mAh. I have a regulated series power supply 0 to 30 volts adjustable to 19.5 volts and can supply 0 to 5 amps. Can I use this safely after setting the correct voltage.

  18. jay

    Thank you! This article provided me with exactly the info I needed (with a bunch of device-specific USB chargers at 5V, choose the one with the highest amperage to charge them universally), from a trustworthy source, in exactly the amount of technical detail needed for someone with only vague memories of highschool physics.

    I’m a bit miffed at google for not ranking this higher in the search results.

  19. Kay

    Hi there!

    I have an HP dv6 laptop that I’ve had for a little more than 2 years. The original power adapter started giving me a problem in that it wouldn’t always supply power to the laptop (the light next to the port wouldn’t always come on, when I plugged it in). I would try it unplugging and plugging it back it in a couple of times and sometimes it worked, others it didn’t.

    I found a replacement HP adapter online for $30 and bought it but it’s not exactly the same as the original one.

    Original (65 Watts)
    Input: 100-240V ~ 1.7A(1,7A) 50-60Hz
    Output: 18.5V(18,5V) — 3.5A(3,5A)

    Replacement (90 Watts)
    Input: 100-240V ~ 1.5A(1,5A) 50-60Hz
    Output: 19V(19V) — 4.74A(4,74A)

    I read this article and it mentioned that the voltage should be as close as possible. Since the voltage differs by half a volt, am I okay to use it or should I look for one that is exactly the same? Also, would the higher wattage harm my laptop or battery in any way?

    Thank you very much.

  20. Mark Jacobs

    Using a slightly higher voltage might have a negative effect on the life of your battery. As Leo says in the article “The device may work with voltages that are close, but often at the cost of shortening the lifespan of the batteries being recharged.” It’s a controversial subject and there are opinions on both sides, but I tend to the better safe than sorry approach.

  21. Rob

    My tomtom worked fine until I used wrong in car charger.Now it won’t start even after mains charge and resets.The charger is input DC=12v. Output DC=10.5v fuse 5A PositiveCentre pin. Tomtom label 5v DC 2A positive pin.Have I “cooked” the battery or worse?

    I don’t know about the battery, but putting 10.5 volts into a device that expects 5 volts is a Bad Thing and could have damaged the electronics inside.

  22. Mildred

    I am looking for an external battery pack for my laptop. I have seen they all say 19 volts but my laptop charger says 19.5volts=2A. Can i use the battery pack?


    Best I can say is “maybe”. It’ll probably work, but it may shorten the life of your computer’s battery by being off by half a volt.

  23. ELMon

    Hi Leo … I need help I have laptop
    19 V …2.15 A…is required power supply
    now my new adapter is 19 V …1.58 A

    it is ok to use that adapter to my laptop?..

    • It’s OK to use, but it may not charge as quickly, or if you’re using the laptop, it may not charge at all.

      • Maxim

        And also his new adapter could potentially overheat or even burn out the power supply, if I understood correctly from the article?

  24. Hermes

    Hi Leo,

    Can you please help me with this question. I am about to buy a jumper battery from called jumperpack. It soppoused to have a usb port with 2.1 amps. My question is can I charge my laptop that takes 19.5 volts at 4.6 amps ? providing that I have the right connection or adapter to go from a usb to my laptop charge connector. I am a truck and bus technician and use my laptop in order to do diagnostics so sometimes I am in a road test and all of a sudden it is a longer road test and my battery runs low and sometimes the bus or truck does not a 12 v power supply for my inverter TRIPP 400 watts. so It would be great that I can provide power to my laptop just to finish my job may be 30 minutes to an hour sometimes. would the 5 volts provide enough power to my laptop ?

    Thanks a lot

      • Lee

        You stated that USB provides 5Vout. You also stated that the power supply output voltage must equal the voltage of the device that you’ll be charging (or at least that’s how I interpreted what your article stated). So, does that mean that the batteries in our USB powered device has a voltage of 5V (i.e. USB voltage input to device = 5V and device battery that needs to be charged =5V)?

  25. cezar

    can i ask question leo i if the voltage is not same and the current is higher what is the effect?

  26. Ken C

    Leo, thank you, your article presents the required information in a way that is easy for those of us that haven’t had the benefit of technical training to comprehend and apply to our particular situation. I think many of us go through the joy of either upgrading or replacing our PC’s on a regular basis and there is just a lack of consistency in the power adapters on the PC’s on the market so we generally have to face acquiring a new back up adaptor to support travel. A great concise article thanks again.

  27. Dawn

    I have a Toshiba laptop that requires 19v and 4.74a. I have a replacement adapter that is 19v 3.42a. Can I use this replacement safely to charge my laptop or do I need to get the 4.74a?


  28. Matt

    So my power hungry smartphone’s charger has an output of 5V @ 1.2 amps, I got a power bank for it that has a matching voltage, but the output is 1 amp, or 2.1 amps. Charging from the 1 amp seems to do fine just takes slightly longer to charge. The 2.1 amp just kills the power bank faster with the same charge time as the wall charger that came with the phone.

  29. Joseph Okeowo

    pls I need help my Xbox 360 AC adaptor burned out by high voltage my question is that if it has affected my Xbox too
    pls reply as soon as possible

  30. param vyas

    Hi Leo, My dell studio 1450 has a 11.V=85Wh battery (TYPE: W358P) which says min 7.26 Ah
    Now the charger i had got with this 9 cell battery was a 65 W charger and hence the laptop would always prompt me to connect a 90 W charger, I did not pay heed and the charger is now dead and i need to buy a new 90W charger.
    But the problem is all the dell chargers up in the market in INDIA are of lower amperage than 7.26 (which the battery reads NOT my old charger).
    1. Does 7.26 Ah on a battery mean that the charger should be of 7.26 Ah or it can be lower? because all the ‘chargers’ read 19.5 V & 4.5A
    2. Does a 19V CHARGER be compatible with a 11.1 V 85Wh BATTERY ? ( your article mentions about matching the specs of the new charger with the specs of the old charger but in my case the old charger itself was faulty)
    Please help me with this.

    • Mark Jacobs

      The amperage should be at least the amperage of the battery. Too low and it might not charge fully and might cause to wear your battery out more quickly. Higher would be fine. The voltage should be as near to the required voltage as anything higher might damage the computer and anything lower might not work.

    • Volts MUST match what the computer expects, or you could damage the computer. 19V is not the same as 11.1V therefor would NOT work.

  31. lawrence

    i have a shaver power adapter from the US that i took to Europe, and plugged it right in….a few mns later…Pfffff (smoke) from the transformer.
    im now back in the US, and the transformer is gone. i.e. when i test is. no juice in the output adapter.
    the original adapter says 4.85v 800mA. i cannot find ANY adapters with the same voltage.
    the nearest i found is 5v 0.8A.
    Will this 0.15v difference fry my shaver or will it work?

  32. Marilyn

    Could someone please tell me if this is a good replacement adapter for my asus laptop:

    OLD ONE:
    INPUT: 100-240V ~ 1.5A (1,5A) 50-60 Hz
    OUTPUT: 19V – 3.42A (3,42A)

    NEW ONE:
    INPUT: 100-240V ~ 1.3 A 50-60 Hz
    OUTPUT: 19V – 3.42A

    Can I use the new one without any consequences on battery and laptop?

  33. Jocy John

    read all the article , one doubt.
    As mentioned earlier “Amperage is taken by (or pulled) by the device being powered”
    lot of cases we experience when the ampere in the power supply is more the device regulator or related component get faulty or burned out .
    one example ‘ go for a simple device mention power rating 12 v 1 amp . if we give a supply of 12 v 3 amp device get faulty “

  34. basilsikfang

    Input Voltage Range: AC 100V – 240V / Power Output: 6.25V 2.5A 16W

    I am looking for a replacement adapter for the Amazon Fire TV box. I bought a refurb off eBay and was trying to see if I can use an 6v/3a/18w adapter.

  35. P.L. Paz

    Hi. This is a very helpful article, but I have this scenario:

    My power bank’s rated power input is 5V , 1A. But when I am using a 5V 1A charger, the charger heats up fast. (And smells foul when I am very near it) When I tried using a 0.7 A charger, the heat is moderate, and on a 0.5A charger, the temperature is normal. What should I use then?

    P.S. All chargers mentioned are in good condition. The USB cables used are the same for every chargers tested.

    • Gene

      You really need to look at the device requirements (in this case your power bank – I guess). It is always possible that you have a “lemon” if your charger heats up fast.

      I am assuming that the “power bank” is the device you’re attempting to charge. I could be wrong.

      It is my understanding that the volts you are trying to input should be the same or less than the device you are charging. While the amps should be the same or they can be slightly higher than the device you are charging.

      I would just state the obvious, use the charger that has a normal temperature as long as it is not damaging the device you are charging. The fact that you’ve charged a device with .5A tells me that the device you’re trying to charge will not blowup and the requirement of that device requires at least .5A. But again, without knowing what your charging exactly it can vary with what device you are actually charging. I would recommend you either look for the fine print or google your device’s input power requirements.

      I hope this helps. Does anyone else have anything to add?

  36. Gene

    I have an interesting question.

    I have a Nintendo 3ds that requires 4.6 Volts and 900 mA (you might as well say 1 amp). Older Nintendo DS’s required 5 Volts so I was ok cutting the charger cable and making my own USB charger out of it so I can either charge it in the wall or with a portable charger.

    I had a vision about just buying an official Nintendo car adapter charger and then making a new cable that was USB to a cigarette lighter socket as a way to try to still use a portable charger.

    Of course I was excited to do it. My thought was that if the Nintendo car adapter charger steps 12 volts down to 4.6 Volts at 900 mA, then this new cable should step 5 volts down to 4.6 at 900 mA. But it did not work.

    I got to doing a little more research regarding USB ports and cables have different amperage capabilities. For example USB 3.0 does 900mA, while USB 2.0 does something like 500mA.

    Unfortunately the gauge of the USB 2.0 cable is really a high number (meaning that the wires are few and small). I’m thinking I should redo my cable and use a USB 3.0 cable because I think it may be able to handle the Voltage.

    When I took my multimeter and took a reading on the output of the car adapter from a 5V charger, it was reading 4.14V or 3.8V, and the Nintendo 3DS charger light would blink.

    Am I getting this concept wrong? Or is a special cable an impossible vision because the car adapter will only work if it is getting 12V and not 5V?

    I have a USB 3.0 cable, but if it is an exercise in futility then I’m just wasting money on a fantasy.

    If I knew what kind of resistor I can buy to solder in with a wire that would be about my only option.

    Thanks in advance,


  37. Hussain

    This is a great article and have all questions answered which I needed. Thanks Leo n keep up the good work!
    Hussain from Maldives

  38. Sally

    Nice article. I have Acer laptop with battery 10.8V – 4400mAh, 48Wh thats 4.15 ah.
    My AC power adaptor burned. I have 2 replacement options .Could someone please tell me which is a good replacement option:
    INPUT: 100-240V ~ 1.5A 50-60 Hz
    OUTPUT: 19V – 3.42A
    Option 1:
    INPUT:100-240V ~ 1.5A 50-60 Hz
    OUTPUT: 19V – 3.9A
    Option 2:
    INPUT:100-240V ~ 1.5A 50-60 Hz
    OUTPUT: 19V –4.74A

    • Mark Jacobs

      Either on should work as the voltages are both the same as the original and the amperages are not a little higher. Being of a closer amperage, I’d go with #1.

  39. Mo'men

    Help me Leo
    I have an infinix zero mobile the charger output is 5 V and 1 A
    i want to buy an asus power bank the output of it is 5 V and 2 A
    is that ok or what?

  40. Karen

    Hi there, wished I had googled this earlier.

    My Power adapter fried the other day, luckily I was at home and didn’t cause a fire!

    Anyway, I have sourced a non-genuine Adapter from fleabay. I know nothing about electronics, except plug them in you have power.

    So I searched high and low and found a replacement however the input is different from the one I had to the one I have purchased. Old one 1.5A, the new one 1.6A, the output matches as does everything else.

    Am I good to go….?


  41. Rahul Sharma

    I have Battery Car that requires 7V output to charge, can i charge that with 5V output charger., What would be the drawback if any. Thanks, your article has provided many insights.

  42. khan

    Dear sir
    Can i use charger of nexus 7 for zenfone 2
    Specs of zenfone 2 charger 5.2 v and 1.25A while as nexus has 5v and 2A
    Please help me i canor decide anything

  43. khan

    And also the company claims that a quick charger of 18w is compatible with this asus device
    but i need to know could it harm my device because i lost my charger and this charger us available right now

  44. Dare

    can i use 6v 10H battery to power my Huawei CPE internet modem with power rating of 12v 2A. though the modem has an in-built battery with a rating of 3.74 1.5A

      • Dare

        Thank you Mark Jacobs. May I please inform you that I read the article and all the comments from the beginning to the end, and if you read closely yourself you will see clearly that nothing in the above article and its many comments address my unique case. I want to power cpe modem of 12 v 2A with a closed lead acid battery of 6v! and 10AH (can you in anyway see the peculiarity of my matter?). If you do please advise appropriately and I will appreciate that! Thanks

  45. Raj

    Could someone please tell me if this is a good replacement adapter for my Sony laptop:
    OLD ONE:
    INPUT: 100-240V ~ 1.5A 50-60 Hz(90W)

    NEW ONE:
    INPUT: 100-240V ~ 1.5A 50-60 Hz(60W)

    Can I use the new one without any consequences on battery and laptop?

  46. mei

    OLD ONE:
    INPUT: 100-240V ~ 1.5A 50-60 Hz(90W)

    NEW ONE:
    INPUT: 110-230V ~ 1.5A 50-60 Hz(60W)

    Can i use the new one?


  47. I’m closing comments on this article since so many people are simply asking questions that are clearly answered by the article.

    Read the article. It’ll tell you what you need to know.

  48. Mark Jacobs

    Here is something related that I discovered. I have a cordless phone that needed a new set of batteries. I bought batteries with a hight amperage than the originals. They only lasted a few months, and it dawned on me that I made a mistake. Putting in batteries that are of a higher amperage than recommended can shorten battery life because the charger doesn’t supply enough amps to fully charge it.