Why do my AA Hybrids take a higher capacity when charged at 150ma compared to 350ma? My really old Energizer wall chargers have a 150ma output and the newer ones are 350ma. Does this mean that my old chargers are better to use? I guess my main question is, Can a NiMh battery store more energy when charged at a slower and lower rate?
How Charger output and rate effect capacity?
- Thread starter fishx65
- Start date
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ElectronGuru
Flashaholic
+1
me too - does the turtle win the race?
me too - does the turtle win the race?
VidPro
Flashlight Enthusiast
umm, yes and no.
the turtle should team up with the hare, and have the best of both worlds.
it would be best if there was a high current at the first of the charge, but intermittant so as to not have a lot of heat. so a 50-50 pulse works good, at as high as 2C (1C averaged)
but when it gets near full, and more of the chemicals are converted over, and there are few things left to change to charged, it is best to go a little slower, because you have so much waste heat, not much of the energy being input is going into the charge. There is still stuff that can be charged, going slow enough to counter the heat issues.
sooo, potentially a slow charge can "put more in" without destroying the cell, but a slow charge doesnt nessisarily cycle the chemicals as well, slap things back into place, reform things, break up crystals, or whatever.
so the answer is BOTH
fast to an 80-90% then slow to finish up.
so much for giving you a definitive answer there
the problem is how do you get a charging device to do all that, it takes a sofisticated tracking and observation and monitoring and all, and all the things that Can be tracked, are also subject to changing when the temps are different, when the capacity is different, when the battery resistance is different, or just a few chemicals here and there in it are different.
so if it takes a $200 charger to extend the life of $30 worth of battery, Only to have the user reverse charge it in a device. then the consumer isnt winning nothing.
not to menation making a simple thing more complex than it needs to be.
when you have a larger investement in batteries, or competitions, or just money to burn, then the $200 charger AND the knowlege to use it is a good idea.
so untill you fork over mass funds for a charger, slow is fine as long as it stops , and fast is fine, and its Nessisary that it stop or slow down, and lightweight topping charges at the end of charge cycles are just fine, to squeese out the last drop.
but even if you get say 1-2% more capacity, its all gone in the first 30 seconds anyways dont sweat over 40ma, its a waste of time.
if your battery is getting 95% , then its still deserves an A
the turtle should team up with the hare, and have the best of both worlds.
it would be best if there was a high current at the first of the charge, but intermittant so as to not have a lot of heat. so a 50-50 pulse works good, at as high as 2C (1C averaged)
but when it gets near full, and more of the chemicals are converted over, and there are few things left to change to charged, it is best to go a little slower, because you have so much waste heat, not much of the energy being input is going into the charge. There is still stuff that can be charged, going slow enough to counter the heat issues.
sooo, potentially a slow charge can "put more in" without destroying the cell, but a slow charge doesnt nessisarily cycle the chemicals as well, slap things back into place, reform things, break up crystals, or whatever.
so the answer is BOTH
fast to an 80-90% then slow to finish up.so much for giving you a definitive answer there
the problem is how do you get a charging device to do all that, it takes a sofisticated tracking and observation and monitoring and all, and all the things that Can be tracked, are also subject to changing when the temps are different, when the capacity is different, when the battery resistance is different, or just a few chemicals here and there in it are different.
so if it takes a $200 charger to extend the life of $30 worth of battery, Only to have the user reverse charge it in a device. then the consumer isnt winning nothing.
not to menation making a simple thing more complex than it needs to be.
when you have a larger investement in batteries, or competitions, or just money to burn, then the $200 charger AND the knowlege to use it is a good idea.
so untill you fork over mass funds for a charger, slow is fine as long as it stops , and fast is fine, and its Nessisary that it stop or slow down, and lightweight topping charges at the end of charge cycles are just fine, to squeese out the last drop.
but even if you get say 1-2% more capacity, its all gone in the first 30 seconds anyways
dont sweat over 40ma, its a waste of time.if your battery is getting 95% , then its still deserves an A
Last edited:
Curious_character
Flashlight Enthusiast
- Joined
- Nov 10, 2006
- Messages
- 1,211
This is a peculiarity of the chargers, not the cells. Very few chargers charge a cell completely up to its capacity. I compared a number of chargers I had, and the amount they put into the cells varied a lot. Your old charger simply does a better job of more fully charging the cells. It has nothing to do with the charge rate, but only the way the charger decides when to terminate the charge.
Actually, there's a charge rate below which you can't fully charge a NiMH cell regardless of how long the charger is connected, but it's less than C/10.
c_c
VidPro
Flashlight Enthusiast
thats right, there might be a timer on some of that stuff.
