How many mAh should my meter read?

[ship69]

Hello

I have a meter to measure how many mAh it takes to charge my Galaxy Note 3.
My Samsung battery has "3200 mAh" written on it.

Does that mean that ,if I first drain the battery flat, given that my phone needs to stay on during the charging process, does that mean that I would expect my meter to register at least 3200mAh, if it is in good condition?

Cheers

J

PS Fwiw, I am using an in-line USB tester called: "UNI-T UT658B USB Tester, Capacity Tester, Current Tester, Voltage Tester,Power Tester,Mobile Power Monitor"


EDIT: At what point should I buy a replacement battery? As last time I bought a battery it didn't seem to make much difference!

EDIT02: I had drained the battery down to "1%" and then charged it at c. 1 amp of current and the meter says "2389 mAh", and that is despite the phone being on an my making a couple of calls on it as I charged it... So, needs a replacement yes?

EDIT03: (I cant see how to reply to comments below so here goes!)
To get clear, if the phone is still on whilst it is being charged, and also if the phone & battery are inefficient, then surely the charger will need to deliver MORE not less charge.
i.e. If there are losses of any sort, one would surely expect the charger to need to deliver MORE than 3200mAh in order to fully charge up the battery, no?

 

[Itsa_Me_Mario]

Does that mean that ,if I first drain the battery flat, given that my phone needs to stay on during the charging process, does that mean that I would expect my meter to register at least 3200mAh, if it is in good condition?

I would it to read within 5-10% of 3200 mAh if it were brand new. Replacing the battery is up to you, but it's not uncommon to hear people loudly complaining about battery life when the capacity is reduced by 15-20%.

 

[Kodak2]

Hello

I have a meter to measure how many mAh it takes to charge my Galaxy Note 3.
My Samsung battery has "3200 mAh" written on it.

Does that mean that ,if I first drain the battery flat, given that my phone needs to stay on during the charging process, does that mean that I would expect my meter to register at least 3200mAh, if it is in good condition?

Cheers

J

PS Fwiw, I am using an in-line USB tester called: "UNI-T UT658B USB Tester, Capacity Tester, Current Tester, Voltage Tester,Power Tester,Mobile Power Monitor"


EDIT: At what point should I buy a replacement battery? As last time I bought a battery it didn't seem to make much difference!

3200mAh is the capacity of the battery. In Theory is has the capacity to deliver 3200mAh in 1 hour, although the phone would never need to use that much current. The charge rate is something completely different, the charge rate is governed by the phone charging circuit and the rate of charge will be faster initially then drop as it gets close to 100%. The charge current will start in the region of 2 to 3 amps depending on phone and charger, and can be higher if it's a phone with a turbo charge circuit.

 

[ship69]

3200mAh is the capacity of the battery. In Theory is has the capacity to deliver 3200mAh in 1 hour, although the phone would never need to use that much current. The charge rate is something completely different, the charge rate is governed by the phone charging circuit and the rate of charge will be faster initially then drop as it gets close to 100%. The charge current will start in the region of 2 to 3 amps depending on phone and charger, and can be higher if it's a phone with a turbo charge circuit.

Wait, surely "amp hours" is simply a measure of "electrical charge" that the battery can deliver whilst still staying over the official voltage rating for that battery.

And "electrical charge" is simply electric current (in Amps) multiplied by time (in hours).
i.e. Amps multiplied by Hours.

So it could either be 1 Amp (1000 milliAmps) for 3.2 hours OR 3.2Amps (3200 milliAmps) for 1 hour, no?

I have a new, supposedly fast charger but depending on which USB lead I use it seldom charges at much above 1 amp. I think 1.6amps is the record.

Either way, the maximum amount of "electrical charge" that comes out of the battery can only be whatever went IN to the battery, no?

And if I made some calls whilst the phone was charging, that would use up additional units of charge, no?

Either way my gut sense is that the charging process should have absorbed at least 3200mAh if the battery was in good shape, no??

 

[Kodak2]

You are assuming that the battery is 100% efficient, which it is not.

"So it could either be 1 Amp (1000 milliAmps) for 3.2 hours OR 3.2Amps (3200 milliAmps) for 1 hour, no?". Yes you can cut it any way you want.

 

[Mooncatt]

If you are checking battery capacity and using an external meter plugged into the USB port, then leaving the phone on would render any readings about capacity useless. That meter wouldn't be able to tell how much current is going to the battery and how much is being used to power the phone itself. For this reason, you should charge the battery with the phone powered completely off.

 

[ship69]

You are assuming that the battery is 100% efficient, which it is not.

"So it could either be 1 Amp (1000 milliAmps) for 3.2 hours OR 3.2Amps (3200 milliAmps) for 1 hour, no?". Yes you can cut it any way you want.

No, if the battery is less than 100% efficient, then it will require additional energy – i.e. additional 'electrical charge' in order to fully charge up the battery. So if the battery is being inefficient, then I would expect the battery to require MORE than 3200mAH in order to fully charge the battery. No?

 

[ship69]

If you are checking battery capacity and using an external meter plugged into the USB port, then leaving the phone on would render any readings about capacity useless. That meter wouldn't be able to tell how much current is going to the battery and how much is being used to power the phone itself. For this reason, you should charge the battery with the phone powered completely off.

Yes, I agree a more accurate reading would be to charge the phone whilst it is off (e.g. overnight)

However surely if the phone is using up electrical energy directly, surely the charger would be required to deliver MORE than 3200mAh rather than less. So the fact that my battery seems to be fully charged by delivering just 2389mAh instead of at least 3500mAh implies that battery is unable to receive 3500mAh and therefore (due to it not being 100% efficient, plus the phone itself using current) it is 100% definitely not able to DELIVER 3500mAh, no?

I shall repeat the experiment with the phone off when I can, but either way I am now told that ALL batteries for a Samsung Galaxy Note 3 phone will be several years old and that even if they haven't been used at all, they will have degraded and no longer be capable of deliverying 3500mAh.

Where can I buy a fresh, NEW battery for a Galaxy Note 3 that still has a decent capacity that is at least close to 3500mAh?

 

[Kodak2]

No, if the battery is less than 100% efficient, then it will require additional energy – i.e. additional 'electrical charge' in order to fully charge up the battery. So if the battery is being inefficient, then I would expect the battery to require MORE than 3200mAH in order to fully charge the battery. No?

If you would like to expand your knowledge on batteries and charging this is a very good web site and an excellent place to start.

https://batteryuniversity.com/learn/

 

[Rukbat]

Wait, surely "amp hours" is simply a measure of "electrical charge" that the battery can deliver whilst still staying over the official voltage rating for that battery.

And "electrical charge" is simply electric current (in Amps) multiplied by time (in hours).
i.e. Amps multiplied by Hours.

So it could either be 1 Amp (1000 milliAmps) for 3.2 hours OR 3.2Amps (3200 milliAmps) for 1 hour, no?

Not exactly, you forgot efficiency, which is quite low for lithium charging. Even charging at 3200mA, it should take about 90 minutes to fully charge from 0% (which you don't do, or the battery could disconnect internally and you need a new one. You don't charge a fully discharged lithium battery - it becomes an explosive device.)

I have a new, supposedly fast charger but depending on which USB lead I use it seldom charges at much above 1 amp. I think 1.6amps is the record.

A Note 3 should charge at about 1,200 mA. (That's set internally by the charging circuit in the phone.) Fast charging requires a phone that can take more than 5 Volts to charge - and the Note 3 can't. (The phone and the charger "negotiate" via the data leads to determine the fastest charge they're both capable of. Since the Note 3 doesn't do fast charging, the charger doesn't see anything on the dala leads so it charges at 5 Volts.)

Either way, the maximum amount of "electrical charge" that comes out of the battery can only be whatever went IN to the battery, no?

The maximum that can come out is less than what went in (efficiency, remember - and you don't take out more than a small percentage of the charge in the battery - explosive device?).

And if I made some calls whilst the phone was charging, that would use up additional units of charge, no?

Yes. If the phone can only draw 1,200 mA, and you're making a call, or even have the phone turned on, part of that 1,200 mA is going to run the phone - the rest will charge the battery.

Either way my gut sense is that the charging process should have absorbed at least 3200mAh if the battery was in good shape, no??

Yes - but draining it to 1% - even once - means that it's not "in good shape".

By the way, 1% doesn't mean that there's only 32 mAh of charge left in the battery - you can't drain it that low. 1% is determined by a calibration file in the phone that equates terminal voltage with percentage charge. 0% is somewhere around 3.2 Volts. (I've gotten batteries in that were drained down to 2.5 Volts [and a few even lower] - it takes a special charger, one that does a pre-charge, to charge them. Just putting them in the phone and plugging in a charger won't charge them. As I said, charging a lithium battery that's discharged too far is playing with a bomb. [Remember the Note 7?])

 

[Mooncatt]

Where can I buy a fresh, NEW battery for a Galaxy Note 3 that still has a decent capacity that is at least close to 3500mAh?

Unless you can convince a manufacture to make you one fresh (doubtful), my guess is nowhere. The market for that battery just isn't there anymore to be worth it for battery manufacturers to produce for that phone. You may get lucky and find an extended battery. I.e. One that started at 5,000mAh, but still has about 3,500 mAh capacity if you're lucky. Just keep in mind those would also suffer the same discharge and degradation issues as the stock battery, so even that one wouldn't last all that long.

 

[ship69]

Rukbat - I'm not sure where you are going with this. I agree with everything you say.

My point stands though that if the battery is supposed to deliver 3200mAh, then I need to be able to put at least that amount of "electrical charge" (ultimately is the flow of a certain number of electrons from A to B) into the battery, in order to have any hope of getting 3200mAh out again!

Due to the inefficiency of the battery the actual mAh that one will get ou will presumably be significantly less that the mAh that one put into the battery during charging. So I imagine that I am looking to put significantly more than 3200 mAh into my battery. (e.g. I am guessing say 3500, 4000mAh??)

If draining the battery so that my Galaxy Note 3 says "1%" genuinely damages or destroys the battery, then surely this is a hideous design fault in the Note 3. Why allow me to accidentally damage my battery just because I use my mobile phone for the purpose for which it was intended?


UPDATE: Last night I drained the battery down to "1%" (I know, but too bad!), turned the phone off and charged it over-night. According to my USB meter, the battery took just under _2,300mAh_ of electrical charge this time without the phone being on during the charging process.

 

[ship69]

Unless you can convince a manufacture to make you one fresh (doubtful), my guess is nowhere. The market for that battery just isn't there anymore to be worth it for battery manufacturers to produce for that phone. You may get lucky and find an extended battery. I.e. One that started at 5,000mAh, but still has about 3,500 mAh capacity if you're lucky. Just keep in mind those would also suffer the same discharge and degradation issues as the stock battery, so even that one wouldn't last all that long.

Last time I looked, any 5000mAh was physically significantly larger than the original 3500mAh battery, and will not fit into the battery cover. I would need a new cover and a new protective case for my Note 3, and it will be heavier & larger than I find acceptable.

 

[Mooncatt]

Last time I looked, any 5000mAh was physically significantly larger than the original 3500mAh battery, and will not fit into the battery cover. I would need a new cover and a new protective case for my Note 3, and it will be heavier & larger than I find acceptable.

That's the trade-off with extended batteries.

 

[ship69]

Unless you can convince a manufacture to make you one fresh (doubtful), my guess is nowhere. The market for that battery just isn't there anymore to be worth it for battery manufacturers to produce for that phone. You may get lucky and find an extended battery. I.e. One that started at 5,000mAh, but still has about 3,500 mAh capacity if you're lucky. Just keep in mind those would also suffer the same discharge and degradation issues as the stock battery, so even that one wouldn't last all that long.

UPDATE:
I have thrown caution to the wind and after contacting various suppliers, I have bought a battery from "All Batteries" here in the UK. They do at least claim to look after their batteries.

I'll let you know how I get on.

J

 

[Mooncatt]

UPDATE:
I have thrown caution to the wind and after contacting various suppliers, I have bought a battery from "All Batteries" here in the UK. They do at least claim to look after their batteries.

I'll let you know how I get on.

J

Good luck!