Screwy Louis Stewart claims that the slower you recharge your cell phone , the slower it will run down.

Very short full chargers will run down much faster.

The capacity of the battery is the same no matter the rate of charge.

What slow charging may do is to extend the life of the battery.

Faster charging will reduce the lifespan of the battery. Lifespan as in the number of charge/discharge cycles it will handle. It would be easy to misinterpret if screwy Louis said your battery won’t last as long if you use the fast chargers.

Also only charging to 80% will extend the life of the battery.

The slower you recharge your cell phone, the slower the battery will degrade.

Apparently, it's true. My iPhone when I plug it at night before going to bed says something like Optimal battery charging scheduled to complete by 8 am.

When I charge it during the day, it charges pretty quickly.

I also learned that keeping a battery charged between 30% to 80% will prolong its life.

When I got a new phone a few months ago, I found that it wouldn't charge at all with most of my old chargers. The guy at the store said some newer phones need a higher amperage charger. I got a couple and darned if he wasn't right. He also said that keeping the charge at about 80% or lower would give longer life.

Slower charging rate over a longer time brings batteries up to snuff better than the reverse. It does not change the rate at which the battery discharges. This applies generally to all batteries.

Hence the modern smart battery chargers for vehicles, unlike the old ones you would set the charge rate at fixed settings like 2A trickle, 10A chanrge, or 20A fast charge. The lower the setting the better for preserving the life of the battery. The new ones with firmware built in are able to charge auto batteries using various charging algorithms, for smarter charging and reconditioning from batteries that have been deeply discharged, etc.

My cell phone hardly holds a full charge for a day, probably exactly for this reason.

Thanks,

There is some “truth” to the statement that a faster charge will result in a faster discharge. Battery indicators are not like fuel indicators, which can actually physically measure the amount of fuel in a tank. A battery indicator estimates the amount of charge based on the battery voltage, which increases as the battery charges.

If you fast charge a battery the voltage may get to a level that indicates full charge, but as soon as it comes off the charger, the voltage begins to drop and thus the charge level appears to drop more quickly.

In other words, the result of a fast charge may be a battery that indicates fully charged when in fact it has not gotten to an ideal fully charged state.

quote:

Originally posted by wcb6092:
Also only charging to 80% will extend the life of the battery.

For those with Pixel Phones, you can set it to not charge more than 80%.

Goto Settings, Battery, Charging Optimization, set Charging Optimization to ON and limit to 80%. I use a wireless charger in my car and, when the charge gets to 80%, the battery stops charging. You need a certain level phone and OS but it works great.

On the latest upgrade it will charge to 100% after the upgrade. That sets the battery level then it charges to the 80% automatically.

Also, since batteries are less than 100% efficient, some of the charge current is converted to heat. The faster the charging rate, the warmer the battery gets and heat tends to reduce battery life (whether charging or discharging).

quote:

Originally posted by SPWAMike0317:
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For those with Pixel Phones, you can set it to not charge more than 80%.
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Mike, thanks for that tip. I've had to replace several batteries in phones/tablets over the years (some with very difficult dis-assemblies involved.

The fewer battery replacements, the better!