Lang Elliott wrote:
> At our local Target store, I just purchased a Ray-o-Vac one-hour quick
> charger for NiMH batteries. It comes with an AC adaptor and also a 12 volt
> plug for use in an automobile. One hour charge time seems pretty fast.
>
> I haven't been following all the postings about NiMH batteries, but am I
> right in assuming that my 1850 mAh Energizer NiMH cells when fully charged
> will outperform Energizer alkaline cells??
The short answer is yes.
The manufacturers do a lot of handwaving to avoid giving us a mAh value
for alkalines, partially as it's dependent on discharge rate. So easy
comparisons are tricky. I've estimated AA alkalines as somewhere in the
vicinity of 1000 mAh. It may be less.
The portadisc manual, for instance rates alkalines as running it for 2.5
hours of recording. With it's original 1500 mAh NiMH that is over 3
hours. I can get three full 74 minute disks with 1800's.
As I noted, NiMH start at a lower voltage than alkalines, but maintain
their voltage through much more of their discharge. The alkalines will
fall below the NiMH at about 40-50% used up. And NiMH will keep the
voltage pretty steady out to 80% of full charge, after that they fall
off fairly fast. It's best to recharge at about the 80% level or even
before. They don't have memory problems can be recharged at any level.
I'm using 1800 mAh NiMH in my MP2, I did get over 5 hours estimated out
of 1 charge, and that was running the MKH-20's. I'm not sure what I can
count on as a routine matter yet. Not enough use to tell. But it's
definitely above alkalines.
The 1800's were demoted from the Portadisc, where I'm now using 1900's.
One hour is fast, really a bit too fast. But you will probably find
that's for the lowest capacity rechargables, which are something like
1200 mAh. Your higher capacity ones will take longer. If not used to
charging NIMH, you will be surprised at how hot they get when charging.
I use the Maha chargers, which are a smaller package than the older
Ray-o-Vac one I have. They also come both AC and car charging. The older
Maha's I have also have a conditioning/discharge cycle available for
nicads. That's the MH-C240F's. I have some of the newer pulsed chargers
the MH-C401FS, which use a pulsed charge system to do it at lower
temperature. They can also do a single cell, the others minimum is 2
cells. But they don't have a conditioning cycle. And for fancy stuff I
have a Maha MH-C777Plus, which has metering for measuring cell capacity,
discharge cycle, and can handle nicad, NiMH battery setups from 1 cell
up to 12 cells or 1-4 cells for LiOn pacs. With alligator clip
connectors and pin contactors for camera pacs it's very versatile.
Walt
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