Oxyride AAA's are rechargeable!
Joe Horn
You know how the 49g+ eats alkaline batteries when you do a lot of
writing to flash memory? Well, never buy alkalines again!
The good news is that Panasonic's new "Oxyride" AAA batteries (also
called "NoOx" by Duracell, or "Nickel Oxy Hydroxide" in general) work
just fine in the 49g+, even though they start at 1.7 volts. They cost
about the same as regular alkalines, but last twice as long (IF you do
a LOT of writing to flash memory). And they have the same multi-year
shelf life as alkalines. So even if that were the end of it, it'd make
sense to stop using alkalines and go with oxyrides immediately.
However, there's even better news! If you have a NiMH recharger that
pumps 200mA or less through the calls (e.g. the Rayovac PS1, but NOT
the "One Hour" Rayovac PS4), you can use it to RECHARGE oxyride AAA
cells, even though everybody says that it cannot be done, or if
attempted will cause explosions, fire, and general pandemonium. But I
do not believe that to be true, unless the cells are raised to a high
temperature by attempting to "fast-charge" them.
Anecdotal evidence: I ran a set of Panasonic oxyrides down to 1.05 volt
each, then put 'em in the Rayovac PS1 overnight. The charger didn't
reject them, trickled juice through 'em for a few hours, and turned off
when the "delta V" went negative. Their unloaded voltage measured 1.6V
at that point. After a few hours of sitting idle, they measured 1.5V
and didn't drop any further during the subsequent 24 hours. They then
ran a 49g+ approximately as long as they did when new.
When they ran down to 1.05 volts again, I charged 'em again... and the
same thing happened: They charged to 1.6V, settled down to 1.5V, and
gave a full run in the 49g+.
This was repeated a third time, and just now I'm finishing up a FOURTH
iteration.
Since the PS1 is a gentle charger, the cells only get slightly warm,
not hot. There has been no leaking, nor any swelling of any of the
cells that's measurable with ancient Sargent-Welch school-lab calipers.
:-) Even if they could only be recharged ONCE they'd impress me far
more than Rayovac's leak-prone "Renewal" rechargeable alkaline cells.
Bottom line: If you use port memory in your 49g+ a lot, use oxyride
batts. You'll save money even if you don't recharge 'em. If you don't
use port memory a lot, use oxyride batts and recharge 'em. Even if you
only charge 'em once and then throw 'em away, you'll be saving money.
Either way, don't buy alkaline AAA's ever again for your hp49g+.
Similar experimentation on Energizer "non-rechargeable" Lithium 1.5V
AAA's will commence when these oxyrides either fail to recharge or
start to leak.
Disclaimer: Your mileage may vary. Different brands of "nickel oxy
hydroxide" batteries might differ in performance and rechargeability. I
do not guarantee anything, nor do I own stock in any battery companies
(or any other companies, for that matter).
Since saving money and the environment is important to us all, please
share with us your own experiences with Oxyride batts. All info,
whether pro or con, is helpful. Thanks!
-Joe-
Joe Horn
Typo. Make that "NiOx".
-jkh-
Brandon Del Bel
manjo
"Brandon Del Bel" <nesci...@gmail.com> wrote in message
news:1143054740.9...@j33g2000cwa.googlegroups.com...
> Bummer, my Rayovac PS3 puts out about 310mA.
hello, you may be interested in posts in
49G+ and USB LED lights....
threed
manjo
rsch...@comcast.net
Joe Horn wrote:
> Good news and better news for hp49g+ users!
>
> You know how the 49g+ eats alkaline batteries when you do a lot of
> writing to flash memory? Well, never buy alkalines again!
That sounds great Joe, I think my Radio Shack 14 hour charger will do
the trick ;-)!
It sounds even better for my DSLR cameras!
Scott
The Phantom
Here one can find the spec sheet for the AAA Oxyride cell:
http://industrial.panasonic.com/www-data/pdf2/AAC4000/AAC4000CE219.pdf
and here is the spec sheet for a AAA NiMH cell, 850 mAh rating:
http://data.energizer.com/PDFs/nh12-850.pdf
and here is the spec sheet for an ordinary AAA alkaline cell:
http://data.energizer.com/PDFs/E92.pdf
---------------------------------------------
There is a review of Oxyride performance here:
http://www.nytimes.com/2005/04/07/technology/circuits/07pogue.html?ei=5088&en=0534c863e76a3718&ex=1270526400&partner=rssnyt&pagewanted=all&position=
The reviewer found that for low drain applications, regular alkaline
cells beat Oxyrides. Comparing the "Constant Current Performance" graph
for the ordinary alkaline to the "Discharge Characteristic 20" graph for
the Oxyride would seem to indicate that the Oxyride is certainly no better
than an ordinary alkaline at low drain. But, at high drain, the Oxyrides
win, a conclusion also supported by the graphs. This means that there must
be a crossover point; a discharge rate at which the performance of the
Oxyride and the ordinary alkaline are equal.
Now have a look at the 850 mAh NiMH spec sheet. The "Discharge
Characteristics" graph showing the performance with 170mA drain (this is
close to 250 mW) indicates that the cell will supply 170 mA for about 3.8
hours. The Oxyride can supply 250 mW for a little over 3 hours. (The
Oxyride endpoint is .7 volts vs. the .9 volts customary for NiMH cells, but
the Oxyride curve is nearly vertical by the time it reaches .9 volts, so
this difference in endpoints won't materially affect our conclusions).
The 100 mW curve shown for the Oxyride is comparable to the 85 mA curve
for the NiMH cell. The Oxyride lasts for about 780 minutes vs. the 600
minutes of the NiMH cell. So somewhere between 100 mW and 250mW discharge
rates, the NiMH cell gives the same performance as the Oxyride cell.
At www.thomasdistributing.com one can buy AAA NiMH cells with 1000 mAh
capacity, and the crossover point would be at an even lower power drain.
At discharge rates higher than 175 mW (estimated) the 1000 mAh NiMH cell
will outperform the Oxyride.
I made some measurements of the current consumption of the HP49G+ with
standard alkalines installed:
Condition of Current
measurement drain
Calc on, doing nothing 18 mA
Calc on, holding ON down 75 mA
Calc running a program 65 mA
Calc on, pressing RED key 30 mA
Calc on, pressing BLUE key 30 mA
I didn't measure the drain while writing to FLASH memory, because I don't
have a FLASH memory for the calculator. However, notice that 65 mA drain
amounts to nearly 100 mW from a 1.5 volt alkaline cell. I would assume
that writing to a FLASH memory would consume substantially more than this,
and therefore would be on the high side of the performance crossover point
for the Oxyride vs. NiMH comparison (1000 mAh NiMH for sure; even 850 mAh
NiMHs would be better if the consumption is >= 250 mW).
So it would seem that for those high battery consumption situations, it's
best to use high capacity NiMH cells; they're even better than Oxyrides.
However, looking at the "Milliamp-Hours Performance" graph on the first
page of the Alkaline spec sheet, it looks like you could expect about 1000+
mAh at a current drain of 65 mA. For ordinary calculating, alkalines will
give the same or better performance than the NiMH. (The Oxyride is not
significantly different in performance compared to the ordinary alkaline at
65 mA drain according to the spec sheets.) And the alkaline won't
self-discharge in a few months of non-use, leaving you with a dead
calculator just when you need it!
Teddy Chiang
reccommend rechargeable NiMH battery. I'm very satisfied
with current NiMH battery. The low battery alert always came
out as battery voltage lower than 3.3V with NiMH battery
(I forgot the actually value). So that I'm sure it could work
with49g+ very well.
Another information: When put the used NiMH into battery
charger and discharge it. It will stop to discharge withing 1 min.
So 49g+ is suposed to use the battery up.
Joe Horn
> I didn't measure the drain while writing to FLASH memory,
> because I don't have a FLASH memory for the calculator.
Unless I'm mistaken, the built-in "Port 2" is flash memory. "Port 1"
was regular memory in the 49G, but seems to be flash memory in the
49g+. Measurements of current consumption writing to the various ports
would be useful.
Brandon Del Bel wrote:
> Bummer, my Rayovac PS3 puts out about 310mA.
It might still work. The problem is not the actual output power, but
rather the propensity of "fast chargers" to refuse to recharge anything
but NiMH or NiCd. But be careful; if the cell gets very hot, abort
before it leaks or explodes! >:-O
Joe Horn wrote:
> Similar experimentation on Energizer "non-rechargeable"
> Lithium 1.5V AAA's will commence when these oxyrides
> either fail to recharge or start to leak.
The AAA Oxyrides endured 6 complete cycles (heavy use to 1.05V,
recharge to 1.6V) before having a shorter life per charge. None leaked
or bulged.
Scott wrote:
> It sounds even better for my DSLR cameras!
If you use your digital camera infrequently, you'll love the long
shelf-life of Oxyrides. NiMH's in a neglected camera die of boredom,
which forces you to swap the batts after every photographic hiatus.
Oxyrides wait patiently in an unused camera without losing their
charge, which means the camera is always ready when you need it.
However, if you use your camera frequently, NiMH is the best way to go,
since the number of shots per charge is comparable to Oxyrides but they
can be charged hundreds of times, not just six. NiMH's short shelf-life
is immaterial when you drain 'em faster than they drain themselves.
-Joe-
Scott Chapin
"Joe Horn" <joe...@holyjoe.net> wrote in message
news:1143229919.8...@j33g2000cwa.googlegroups.com...
> Scott wrote:
>
> > It sounds even better for my DSLR cameras!
>
> If you use your digital camera infrequently, you'll love the long
> shelf-life of Oxyrides. NiMH's in a neglected camera die of boredom,
> which forces you to swap the batts after every photographic hiatus.
> Oxyrides wait patiently in an unused camera without losing their
> charge, which means the camera is always ready when you need it.
>
> However, if you use your camera frequently, NiMH is the best way to go,
> since the number of shots per charge is comparable to Oxyrides but they
> can be charged hundreds of times, not just six. NiMH's short shelf-life
> is immaterial when you drain 'em faster than they drain themselves.
>
> -Joe-
>
I think where they might shine in photographic work, is to keep them as
backup/standbys, as this thread describes them. If your NiMH batteries crap
out in the middle of a shoot, the NiOx batteries could be a godsend. NiMH,
NiCad, and Li-Ion batteries give out at the darndest times, and it's not
reassuring to have like batteries in reserve.
Scott
The Phantom
>Phantom (in addition to lots of great data) wrote:
>
>> I didn't measure the drain while writing to FLASH memory,
>> because I don't have a FLASH memory for the calculator.
>
>Unless I'm mistaken, the built-in "Port 2" is flash memory.
Is that what you were referring to when you spoke of writing to FLASH? I
thought you meant a removable FLASH card.
Joe Horn
> Is that what you were referring to when you spoke of writing to FLASH?
> I thought you meant a removable FLASH card.
Ah, good point. I had assumed that writing to the SD card would be no
different from writing to built-in flash memory... but they must be
different because the SD card has its own electronics, and different SD
cards runs at different speeds and using different amounts of power.
Phooey.
-Joe-
The Phantom
>Phantom (in addition to lots of great data) wrote:
>
>> I didn't measure the drain while writing to FLASH memory,
>> because I don't have a FLASH memory for the calculator.
>
>Unless I'm mistaken, the built-in "Port 2" is flash memory. "Port 1"
>was regular memory in the 49G, but seems to be flash memory in the
>49g+. Measurements of current consumption writing to the various ports
>would be useful.
Copying a large backup object to port 2 took 65 mA until it was done when
the current blipped up to 75 mA for about .1 second.