4V phone charger

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Joseph
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4V phone charger

Post by Joseph » Wed Jul 15, 2020 7:38 am

Hi, I noticed that on my last phone, leaving it on charge too long ruined the battery because the battery's voltage range for longest life is lower than the fully charged level. I thought of trying to find a charger that puts out only 4.somethingV instead of the more common 5V. I've been turning this phone's maximum battery saving mode on to reduce the charge/discharging, but that has drawbacks because then I can't use the battery alarm app to warn me when a certain charge level gets reached, and only a small number of apps work in power saving mode.

I'm searching for a charger with all the same form factors as a standard 5V charger for a non-Apple phone, but with an output somewhere below 5V.

I'd consider the possibility of removing some insulation from the charger wires and placing a simple shunt regulator across the plus and minus wires, but that would take some time and money.

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dacflyer
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Re: 4V phone charger

Post by dacflyer » Thu Jul 16, 2020 5:04 am

you could also ad in diodes, simpler to do. they drop the voltage a bit. maybe you just need 2 or 3 in series.

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Joseph
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Re: 4V phone charger

Post by Joseph » Thu Jul 16, 2020 12:19 pm

I didn't think of diodes. Maybe diodes in series with a kind of high power white LED. Then I wouldn't have to cut the charger cord wires, just remove some insulation, which on other things I've done by melting with a lighter
Although just adding diodes in series needs only one wire bared but also cut.

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haklesup
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Re: 4V phone charger

Post by haklesup » Thu Jul 16, 2020 1:23 pm

using the charger that came with the phone is the best way to get the most life out of the battery (its the only one you can count on as being engineered to work best), also keeping it cool as much as you can helps. Your old phone, I don't know about but battery management and battery technology in newer phones has come a long way in every model year. Reducing voltage is likely to only make charging take longer, most phones now have a buck boost regulator built into the charge circuits and what you put on the USB connector may have little relation to what's applied to the internal battery terminals.

What model phone are you using now? there are forums that may shed more light on battery issues for a particular model. Look for a teardown web page for example.

FYI
https://www.thebatteryshow.com/en/home.html

If you ask me, Its easier to just buy a replacement battery with higher capacity than the original and put it in when it gets to be 3 or more years old. Opening a phone if not as hard as it looks if you study a few youtube videos first.

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Joseph
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Re: 4V phone charger

Post by Joseph » Thu Jul 16, 2020 2:28 pm

I have a Samsung Galaxy J7. I've tried different chargers, and haven't noticed much if any difference even, with trying one of the Samsung chargers here. I don't know which one came with the phone, probably a (Samsung) 2A one.

The way it seems to work, it could be helpful to me if the power input from the adapter happened to be just enough to keep the phone in charge/discharge equilibrium while in normal mode. Then if I put it in power saving mode it would be able to charge. It doesn't have to charge very fast.

I tried a small charger rated 600mA for when I was using a hotspot for Internet, thinking it would put out less power, but I haven't noticed it charging any slower than a Samsung 2A one.
Some of the Samsung chargers I have could be counterfeit though.

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haklesup
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Re: 4V phone charger

Post by haklesup » Tue Jul 21, 2020 10:17 am

you'll drive yourself crazy if the only thing you are observing is how long it takes to charge, you need to start measuring charge voltage and current directly to learn more about the relationship in the context of your phone and what critical cutoff points are if you try to make the voltage variable. Just search amazon or ebay for "USB current meter" you will find many with low cost, get one that has a lot of features and works for more than 5V (some older models are limited)

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Weaver84
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Re: 4V phone charger

Post by Weaver84 » Fri Aug 28, 2020 11:08 pm

4V voltage, will the charging time be extended?

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