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New Li-ion Battery charging

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VictorPS

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Why for new Li-ion battery, for first charging will advice to charge at least 8 hours to achieve 100% capacity?

Later on, just 4 hour is enough for full charge?

What happend if fail to do so? And why?

Thank you,
 
battery needs periodic full discharge and charge because any part of the cell/plate without activity results to sulfation.
 
penoy_balut said:
battery needs periodic full discharge and charge because any part of the cell/plate without activity results to sulfation.
Sorry, but you are wrong.
This is a lithium-ion battery. You are talking about a lead-acid battery. They are completely different.
Both are destroyed if they are completely discharged. A lead-acid battery has lead plates that get sulfated from the sulfuric acid if it is discharged for a long time. It should be kept charged.
 
VictorPS said:
Why for new Li-ion battery, for first charging will advice to charge at least 8 hours to achieve 100% capacity?

Later on, just 4 hour is enough for full charge?

What happend if fail to do so? And why?

Thank you,

I have heard it for Nicad and Nimh cells.
Li-Ion and Li-Polymers use special chargers which controls both the charging voltge and current for the battery, The max charge rate recommended is 1C . because the voltage of the charger must be the same with the nominal voltage of the battery so if you charge your battery at 1C then it would be charged in 2 hours Max and if you charge your battery at 0.2C then 10 hours is need for the battery to be charged...
 
epilot said:
I have heard it for Nicad and Nimh cells.
Li-Ion and Li-Polymers use special chargers which controls both the charging voltge and current for the battery, The max charge rate recommended is 1C . because the voltage of the charger must be the same with the nominal voltage of the battery so if you charge your battery at 1C then it would be charged in 2 hours Max and if you charge your battery at 0.2C then 10 hours is need for the battery to be charged...
This is what I know too, but if you read user manual of your handphone, or eletronics devices that use battery power, you will notice the manufacturer is suggest double charging time for first use.

However, the intelligent Li-ion charger will cut off the battery if it already fully charge, so it seem like meaningless if we leave the battery in charger for double time for first use, or it is working in trickering mode?

But manufacturer suggest that must be a reason behind, or they never change/update their manual and think it is still NiMh battery?

It is conflicting and confusing to me...
 
audioguru said:
Sorry, but you are wrong.
This is a lithium-ion battery. You are talking about a lead-acid battery. They are completely different.
Both are destroyed if they are completely discharged. A lead-acid battery has lead plates that get sulfated from the sulfuric acid if it is discharged for a long time. It should be kept charged.

i don't know if others experienced the same, i have a Li-ion battery that i keep on charging even if its just 10 or 20% discharged, it did not last a year while my new one which i use up to full discharge (low enough to operate the device) before recharging works up to this time at approximately two and a half year.
 
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VictorPS said:
Why for new Li-ion battery, for first charging will advice to charge at least 8 hours to achieve 100% capacity?

Later on, just 4 hour is enough for full charge?

What happend if fail to do so? And why?

Thank you,


my guess is its like a "break-in" or something.. i used to play tamiya and ive learned, tho i was using ni-cad, that you can train your batteries.. the way they discharge/use up the energy stored.. i guess thats what its for..
 
penoy_balut said:
.... my new one which i use up to full discharge (low enough to operate the device) before recharging.
A full discharge is to a very low voltage, usually 0V. Then a Li-Ion battery will be ruined. A voltage that is still enough to operate the device is usually fine, since the device is probably smart enough to shut-off before the battery is ruined.

Batteries are different. One might not last but another might last many years. It also depends if the charger over-charges which is bad for batteries.
 
penoy_balut said:
i don't know if others experienced the same, i have a Li-ion battery that i keep on charging even if its just 10 or 20% discharged, it did not last a year while my new one which i use up to full discharge (low enough to operate the device) before recharging works up to this time at approximately two and a half year.
Usualy isn't OK to top-up a batery (discharge it before to at least .4XC). This problem apears because the cristals inside the bat grow biger and that lowers the active surface. This situation is a PIA:D esp for NiCd but afects LiIon&LiPol.
Once in a while (like 6 months or so) u might want to discharge the bat to 60-70% of nominal voltage to reduce the size of those cristals. Do not cros that 60% limit!
 
li-ion cell voltage must not go outside the range of approx 2.3V~ 4.3V. discharging or charging outside those limits may result in permanent cell damage or in the case of overcharge....thermal runaway and cell explosion. That's why they have safety circuits that keep the cell within this operating voltage range.

Not sure why mfr would recommend 8hr charge the first few times....unless they are charging at a very slow rate and don't want an impatient consumer to pull off charger early and complain about short discharge times.
 
Surely its a fact that most rechargeable batteries lose their capacity if they are kept near fully charged most of the time.
They seem to need the exercise of a dicharge every so often to the point that the equipment fails to work. It seems like they need the exercise.

I always let my shaver discharge to near its end point, which results in a fortnightly stubble but the batteries last for years.
 
Last I heard it's usualy best to keep a pack within 40% or so of a full charge. Discharge to 'empty' actually stresses out the cells chemistry. Putting something back on the charger after only a brief use is probably just as bad such as a shaver, but it's probably the infrequent charge cycle that's makeing it last longer.
 
Much of what's being suggested here is pretty far off.

First off, NEVER try to charge a li-ion/li-polymer batt manually. The charging algorithm is very specific, generally it is a fixed voltage (current limited though) until the current drops below a particular threshold for that cell type and then the power MUST be cut off. It's also more complicated for series cells. Failure to shut off at the right time will overcharge the cells. Lithium technologies are very sensitive to overcharge relative to any other rechargeable. At best, this will permanently damage these particularly expensive cells. At worst, it will catch fire- this is not hard at all to do with li-ion.

Now back to this comment on longevity. Li-ion should never be run totally dead (near 0v), but no "proper" device will do this. They will shut off when the voltage drops below a specified threshold and this is what your camcorder calls "dead".

Storage. Li-ion/li-po are actually degraded by time left at full charge, completely opposite from lead-acid. Calendar lifespan is dramatically increased by storing at like 1/2 charge or less. Unlike lead-acid, the number of complete deep cycles doesn't have much effect on its lifespan. The time spent with a full charge, or near to it, is the big factor.

There are some who maintain that a particular battery type's performance can be improved by conditioning it early on. In some cases this may be true, but if so it's not a really significant effect you should concern yourself with. Just go by mfg's instructions.
 
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