Rapid charging good or bad for NiMH batteries?

In my research I found that some people say that rapid charging is good
for NiMH batteries and others say it's bad, so I'm confused.

Can anyone shed some light on this matter?

Thanks for your help.

"Bruce W.1" wrote in message
...
In my research I found that some people say that rapid charging is good
for NiMH batteries and others say it's bad, so I'm confused.

Can anyone shed some light on this matter?

Thanks for your help.

Now that you are confused, you will fit in well here.

Bruce W.1 wrote:
In my research I found that some people say that rapid charging is good
for NiMH batteries and others say it's bad, so I'm confused.

Can anyone shed some light on this matter?

Thanks for your help.

The conventional wisdom is that it's bad, but at less than $2.50 for 2300 mah
AA's, why use a slow charger? There may be a definitive analysis of the number
of recharges using fast vs. slow charging out there, but I haven't seen it.

That is what I say. When most cams take either 2 or 4 of the AA size and
you can get them and a charger for about$ 15 why worry about it. Not sure
about all the cams but even the non AA batteries cost about $ 20 for a new
one and usually last atleast a year.


"deacon" wrote in message
t...
Bruce W.1 wrote:
In my research I found that some people say that rapid charging is good
for NiMH batteries and others say it's bad, so I'm confused.

Can anyone shed some light on this matter?

Thanks for your help.

The conventional wisdom is that it's bad, but at less than $2.50 for 2300
mah
AA's, why use a slow charger? There may be a definitive analysis of the
number
of recharges using fast vs. slow charging out there, but I haven't seen
it.

Bruce W.1 wrote:

In my research I found that some people say that rapid charging is good
for NiMH batteries and others say it's bad, so I'm confused.

It reduces the number of cycles that the battery will last. I'd get the
Maha MH-C401FS which has a selectable charge rate. You can slow charge
overnight, or do a fast charge when needed. Then there are the
"ultra-fast" chargers, which should be avoided. These are like 3.4A
charging rate.

See: http://nordicgroup.us/chargers/

Bruce W.1 wrote:
In my research I found that some people say that rapid charging is
good for NiMH batteries and others say it's bad, so I'm confused.

Can anyone shed some light on this matter?

Thanks for your help.

I don't have the facts on it, but I work under the expectation that slow
is better but fast is not a problem IF they don't overheat. I don't expect
either to be a real problem and I have never lost any sleep over it.

--
Joseph Meehan

26 + 6 = 1 It's Irish Math

"Bruce W.1" wrote in message
...
In my research I found that some people say that rapid charging is good
for NiMH batteries and others say it's bad, so I'm confused.

Can anyone shed some light on this matter?

Thanks for your help.

Rapid charging, while convenient, is not good for any battery. Rapid
charging is accomplished by increasing the average current flow into the
battery in order to save time. Increased current flow means increased heat.
The increased heat will tend to boil off more of the chemicals in the
battery than slow charging. For every 18 degrees F increase in the
battery's temperature, the reaction doubles. This boiling off of the
chemicals in the battery will eventually lead to a decline in the battery's
storage capacity. That all being said many people do not care if they get
only 100 cycles versus 500 cycles of a Ni-MH battery and are willing to make
the trade off.

In article ,
"Harvey" wrote:

Rapid
charging is accomplished by increasing the average current flow into the
battery in order to save time. Increased current flow means increased heat.
The increased heat will tend to boil off more of the chemicals in the
battery than slow charging. For every 18 degrees F increase in the
battery's temperature, the reaction doubles.

Which is why the fast Ansmann chargers have an automatic fan that comes
on automatically to maintain the optimal temperature in the cell while
charging a 2500 mAh NiMh cell in 10 to 40 minutes. Naturally, being a
smart charger, it switches each sell to trickle charge mode as that cell
reaches full charge.

http://www.ansmann.de/en/index.htm?v...description&pr
2id=&appid=

--
To reply no_ HPMarketing Corp.

Bruce W.1 wrote:
In my research I found that some people say that rapid charging is good
for NiMH batteries and others say it's bad, so I'm confused.

Can anyone shed some light on this matter?

Thanks for your help.

Some batteries, and chargers, are made in a special way for fast
charging. If using those, it probably doesn't cause any harm. Fast
chargers are likely to cause the batteries to warm up more than is good
for them, and may shorten there useful life. But with NIMH batteries
running less than $1 each, why worry about it?


--
Ron Hunter

"Bob Salomon" wrote in message
...
In article ,
"Harvey" wrote:

Rapid
charging is accomplished by increasing the average current flow into the
battery in order to save time. Increased current flow means increased
heat.
The increased heat will tend to boil off more of the chemicals in the
battery than slow charging. For every 18 degrees F increase in the
battery's temperature, the reaction doubles.

Which is why the fast Ansmann chargers have an automatic fan that comes
on automatically to maintain the optimal temperature in the cell while
charging a 2500 mAh NiMh cell in 10 to 40 minutes. Naturally, being a
smart charger, it switches each sell to trickle charge mode as that cell
reaches full charge.

http://www.ansmann.de/en/index.htm?v...description&pr
2id=&appid=


Interesting. You need to use special fast charge batteries with that unit.