45w charger

[bigguh]

45 minutes from 0 to full charge would be a 1.33C charge, which would probably destroy the battery on the first charge. The battery is 4.3 Amps, so you can't charge it at more than 4.3 Amps and, since charging isn't 100% power transfer (nothing is), it takes over 1 hour from 0% to 100%. (No matter which lithium battery we're talking about, no matter which carrier, no matter what power in the battery. It's physics, and the fact that lithium batteries can't be charged at greater than their current rating.)

But discharging the battery to 0 kills it quickly, the best operating range is 45%-100%. Since the battery gets warmer as the charge in the battery goes up, it usually only fast charges to 70%, so it's only fast charging for the first 25% of the time (to a 70% charge, then it drops back to normal charge, to keep the phone from becoming a Note 7. It's still going to take normal charge time for the last 30% of the charge, even if they could charge it from 45% to 70% in a few seconds (which would leave tiny pieces of phone embedded in the walls).

Bottom line - the reason they can't speed charging up much more is the laws of physics.


1. Discharging it to 1% regularly will mean a battery replacement is in your very near future.

2. It doesn't fast charge from 70% to 100% as it is. If you charge it starting at 70%, no matter which charger you're using, the phone is only asking the charger for a normal charge.

I definitely agree with the general sentiment here. My research has shown me that these lithium batteries are most optimal between 40 and 80 percent. While I am not completely sold on it, the app AccuBattery does provide much useful information.

You said that fast charging stops at 70%. I have always seen the rate slow down once it reaches 80%, not 70%. Either way, the batteries like to remain between 40 and 80 and are considered to be safest (least volatile) between those percentages. This is why they are always shipped with around 50 or 60% charge.

Above 80% and below 25% they are considered to be in extreme operating regions. AccuBattery also provides estimates of battery wear based on your charging session. For example, I went from 20% to 57% and the app said the battery wear was just 0.05 cycles (5% of a full 0-100 cycle) even though I charged the battery 37%. As you get closer and go above 80%, that wear estimate goes up drastically. Going all the way to 100% increases the wear significantly. So, as I try to explain to my wife, leaving your battery plugged in overnight AND always charging to 100% are two of the worst things you can do for your battery...at least when it comes to how long the battery will last over the long term. You probably would have to keep the phone for about 18 months to really see degradation, but I know people who have seen changes in their batteries after about a year. Those are the same people that charge to 100% and leave the phone plugged in overnight. So, if you upgrade your phone every year, this is likely to matter very little to you.

Another observation, when below 20 or 25%, and when at 100%, I have noticed that the battery drops faster than when it is in the more optimal range.

 

[Mike Dee]

I definitely agree with the general sentiment here. My research has shown me that these lithium batteries are most optimal between 40 and 80 percent. While I am not completely sold on it, the app AccuBattery does provide much useful information.

You said that fast charging stops at 70%. I have always seen the rate slow down once it reaches 80%, not 70%. Either way, the batteries like to remain between 40 and 80 and are considered to be safest (least volatile) between those percentages. This is why they are always shipped with around 50 or 60% charge.

Above 80% and below 25% they are considered to be in extreme operating regions. AccuBattery also provides estimates of battery wear based on your charging session. For example, I went from 20% to 57% and the app said the battery wear was just 0.05 cycles (5% of a full 0-100 cycle) even though I charged the battery 37%. As you get closer and go above 80%, that wear estimate goes up drastically. Going all the way to 100% increases the wear significantly. So, as I try to explain to my wife, leaving your battery plugged in overnight AND always charging to 100% are two of the worst things you can do for your battery...at least when it comes to how long the battery will last over the long term. You probably would have to keep the phone for about 18 months to really see degradation, but I know people who have seen changes in their batteries after about a year. Those are the same people that charge to 100% and leave the phone plugged in overnight. So, if you upgrade your phone every year, this is likely to matter very little to you.

Another observation, when below 20 or 25%, and when at 100%, I have noticed that the battery drops faster than when it is in the more optimal range.

Addressing only your last paragraph.

The device is measuring a voltage drop and percentages are not really linear.

 

[james702283]

45w vs 25w comparison charge times are not drastic.

 

[Mr-Guy]

I have been using the 45w charger to quickly pump up the battery from say 65% to 85, in less than 30 minutes. That's convenient, but have not used it for regular charging. I have to think that hard charges all the time can't be good for long term battery health.

 

[eshropshire]

I have been using the 45w charger to quickly pump up the battery from say 65% to 85, in less than 30 minutes. That's convenient, but have not used it for regular charging. I have to think that hard charges all the time can't be good for long term battery health.

Have you tested the same amount using the 25w charger? I was considering getting a 45w charger, but the 25w is so fast I was not sure there would be much benefit.

 

[Mr-Guy]

Have you tested the same amount using the 25w charger? I was considering getting a 45w charger, but the 25w is so fast I was not sure there would be much benefit.

I have, and it definitely is faster at those levels. At 60% to 85% takes about 30 minutes at 45w...and well over an hour for the same with the 25.

 

[Mike Dee]

I have, and it definitely is faster at those levels. At 60% to 85% takes about 30 minutes at 45w...and well over an hour for the same with the 25.

Something isn't quite right if it takes an hour wirh 25w to go from 60% to 100% and even worse from 85% to 100%

 

[jhimmel]

True. 60 minutes from 60% to 85% on the 25W charger doesn't sound right. I think it would take me about half that.

Something isn't quite right if it takes an hour wirh 25w to go from 60% to 100% and even worse from 85% to 100%

 

[Mike Dee]

True. 60 minutes from 60% to 85% on the 25W charger doesn't sound right. I think it would take me about half that.

Mine is at 83% as I'm typing and its says 30 minutes with the 25W.

From zero if I recall correctly someone said it was a little over an hour.

 

[j_hansen]

Mine is at 83% as I'm typing and its says 30 minutes with the 25W.

From zero if I recall correctly someone said it was a little over an hour.

1h 5min for the 25w and 50min for the 45w

 

[DARK Vader777]

I just got the 45w charger. I wouldn't of bought it but it's here courtesy of my daughter.
I am not impressed with it. I thought I'd see this dramatic difference. It's faster, but not worth the money spent. I'll just keep using my 25w charger and throw this in my travel bag when needed.

I would never tell my daughter that but it is what it is.

 

[Mike Dee]

I just got the 45w charger. I wouldn't of bought it but it's here courtesy of my daughter.
I am not impressed with it. I thought I'd see this dramatic difference. It's faster, but not worth the money spent. I'll just keep using my 25w charger and throw this in my travel bag when needed.

I would never tell my daughter that but it is what it is.

I'm wondering if it was actually created for the Note or it already existed for some of their tablets or chromebooks. Because the difference in wattage is almost double of the stock one and certainly not needed to achieve that small gain.

 

[j_hansen]

I'm wondering if it was actually created for the Note or it already existed for some of their tablets or chromebooks. Because the difference in wattage is almost double of the stock one and certainly not needed to achieve that small gain.

Maybe it's just a matter of a later software update and we get the use of the chargers full potential

 

[Mooncatt]

Maybe it's just a matter of a later software update and we get the use of the chargers full potential

Unlikely. The only time you would see higher charge rates is when the battery is at a lower charge state. Once you get above about 50%, it moves to the constant voltage, variable current stage where the charging rate slows. Think of it like filling a bucket of water. If you don't lower the pressure as it fills, water will just splash out, but you can fill it to the brim if you slow the water flow as it nears the top. The same happens on a chemical level with Li-ion battery charging. Another quirk of them is the faster you charge in the first stage where, the longer the second stage will take. That's a chemical property of the battery itself, and not something a software change can overcome without increased risks of damage.

 

[j_hansen]

Sorry what I meant was more like that the charging is maybe capped at where it is now but that there is potential for more just not fully tested yet and therefore not released

 

[Mooncatt]

Sorry what I meant was more like that the charging is maybe capped at where it is now but that there is potential for more just not fully tested yet and therefore not released

My earlier comment would still apply.

 

[Mike Dee]

Maybe it's just a matter of a later software update and we get the use of the chargers full potential

I'm not certain charging at a higher rate would be a good idea. I haven't done the math, but if we let it charge at a higher rate or full throttle it might exceed the max C rate. @Rukbat might be able to explain it better or correct me if I explained it wrong.

 

[Rukbat]

I'm not certain charging at a higher rate would be a good idea. I haven't done the math, but if we let it charge at a higher rate or full throttle it might exceed the max C rate. @Rukbat might be able to explain it better or correct me if I explained it wrong.

A Quick charger, Dash charger, PD charger or any of the others won't supply more voltage than the phone asks for (and if the phone can't speak the charger's language, it gets a 5 Volt charge). The current being drawn by the phone is determined by the phone - the charger doesn't "push" charge into the phone, the phone draws current from the charger. (A 100 Watt light bulb - ~1 Amp at 110 Volts, still draws that ~1 Amp ... from a "charger" [your house wiring" that can supply 200 Amps].)

Bottom line - while it's doubtful that any phone has a software-settable charging chip. even if one did, the charge rate for the maximum charge seldom gets near 1C. (1C is a 3500mAh battery being charged at 3.5 Amps - or 3,500 mA.) The normal fast charge for a phone is about 0.5C between 40% and 70%. Below 40%, and above 70%, they still revert to slow charging. (Which could be exceeded in most cases. From 0% to about 20% it's best not to push it, but from 20% to about 90%, a 1C charge would be okay. More than a 0.5C charge as the battery is nearing full charge is no good - the charger [the chip] should have switched from constant current charge to constant voltage charge by then. That floats the battery at about 4.1 Volts until it's charged [during which time the battery draws almost no current until it reaches 4.1 Volts. At that point, since there's no difference between the charging voltage and the battery voltage, no charge occurs.])

 

[EMGSM]

I was considering getting a 45w charger, but the 25w is so fast I was not sure there would be much benefit.

My thoughts exactly. IMO the benefits don't outweigh the cost of the 45W charger. I'm sticking with the 25W unless I can get a good deal on the 45W.

 

[Mr-Guy]

Have you tested the same amount using the 25w charger? I was considering getting a 45w charger, but the 25w is so fast I was not sure there would be much benefit.

I have, and I use both. I only SUPER charge the phone @ 45w on a need to basis...usually when I am in a hurry and don't want to leave with the phone @ 60% or less. I didn't pay for the 45w charger so it was a no brainier.