9V NiMH batteries, high capacity, any good deals?

J

Joerg

Jan 1, 1970
0
Hello All,

At church we are using Ansmann 9V/250mAh NiMH batteries, lots of them.
After a few years they are gradually reaching the end of their useful
life. Looking around I found they now cost about $13 a pop and up. Amazon even lists them for a whoppping 20 bucks. Yikes. Maybe because of the falling Dollar. Is there any other brand from Asia that's a good deal? I'd rather not buy from some of the east coast photo dealers anymore because last time I experienced, ahem, not so honorable behavior. Oh, and to those who develop portable gear: Do _not_ design around 9V batteries ... J Joerg Jan 1, 1970 0 Tim said: Nickel-Cadmium, Nickel Metal Hydride, and LeClanche (dry) cells all have a useful life that extends down to about 0.9V / cell (this is more debatable with Ni-whatever, as the knee is pretty sharp after 1.1V/cell -- dry cells tend to peter out, rather than dying off suddenly). Dry cells will give you more time above 7.2V than NiCd or NiMH, but if you die off at 7.2V you're cheating your customer out of half of his battery capacity. So go ahead and design _properly_ for 6-cell NiCd, NiMH or dry cell use -- just remember that means you should run correctly from a hair over 9V (fully charged dry cells) down to 5.4V (just about crapped out all of above). You can get away with 6V at the low end, hurting your dry cell customers more than you Ni-whatever customers. But I'd go all the way down... I did some designs with 9V. Grudgingly, and only because the customer insisted on it. They sell their own 9V custom batteries and didn't want to switch. It's been too long ago but AFAIR we did go to well under 6V. Can't do that with NiMH or you'd kill them really fast. One cell reversal and it's over. Three reasons I do not like 9V at all: First, the energy density is lowish. You get 9V/250mAh in about the space of a 1.5V/2600mAh, not a good deal. Then, 9V batteries are freaking expensive. >>$10 for NiMH
whereas a AA cell costs less than two bucks. Same with dry cells. You
cannot get a decent quality 9V battery under a buck while it is easily
possible to buy quality AA dry cells for under 30c. Last but not least
the dreaded contact buttons. I lost count how often either the battery
contact ripped out or, worse, the pad that connects to the battery tore.
IMHO this whole 9V block battery concept was ill-conceived from the
beginning.

But what can ya do? All the church wireless stuff runs on those 9V
batteries. But I'll make darn sure that anything we buy for the future
will use AA.

J

Jan 1, 1970
0
first hit on ebay is pack of four 9v/300mAh buy-it-now US$12.60 Well, yeah, the green ones from some unnamed manufacturer in China. Doesn't even say whether it's a 6-cell or 7-cell design. http://cgi.ebay.com/4-x-Ni-MH-300mA...emQQptZLH_DefaultDomain_0?hash=item33566cf34f We'd really prefer a brand name. Our experience with no-names was not very good over the years. Pastor's mike quitting in the middle of the sermon is sort of the worst case. Last Sunday the pulpit mike quit in the middle of the 2nd bible reading. *POCK* ... congregation a bit startled ... RF carrier gone :-( J Joerg Jan 1, 1970 0 Jim said: Make your own adapter ? We don't have enough nerds at church to be sure they don't then just jam them into the usual chargers J Joerg Jan 1, 1970 0 linnix said: How much current is the device drawing? What is the charge/discharge pattern? How about supercaps? I have seen someone building 9V boxes with supercaps. I'd say about 50mA continuous, for about 1-1/2 hours per stretch. It's all wireless mikes, four Sennheiser EW-series and one older Shure Marcad system. Ideally we don't like to change because 1st service, education hour and 2nd service run almost back to back. Super caps would never hold. J Joerg Jan 1, 1970 0 Spehro said: Don't knwo about the 250mAh rating, but I've had good luck with GP (GoldPeak) batteries. Eg. http://www.budgetbatteries.com/gp-b...-9-volt-rechargeable-batteries-bb-000494.html Some battery capacity ratings are a bit optimistic anyhow. 170mAh won't work well for us. Back then, probably about 3-4 years ago, I tested various 150mAh, 170mAh, 200mAh and those Ansmann 250mAh rechargeables against each other. Essentially by placing them inside a wireless mike and let it run until battery voltage cutout. The Ansmann clearly won, big time. But AFAICT they are slightly non-standard in size, meaning there may be situations where you can't squeeze them in without undue force. M Martin Riddle Jan 1, 1970 0 Joerg said: Hello All, At church we are using Ansmann 9V/250mAh NiMH batteries, lots of them. After a few years they are gradually reaching the end of their useful life. Looking around I found they now cost about$13 a pop and up.
Amazon even lists them for a whoppping 20 bucks. Yikes. Maybe because
of the falling Dollar.

Is there any other brand from Asia that's a good deal? I'd rather not
buy from some of the east coast photo dealers anymore because last
time I experienced, ahem, not so honorable behavior.

Oh, and to those who develop portable gear: Do _not_ design around 9V
batteries ...

We used to use Vartas, many years ago. I'm sure they have NIMH now.

Search, seems to be $7-$10 per battery.

Cheers

J

Joerg

Jan 1, 1970
0
TTman said:
How about 2 cell LIPO ? 8.4V

We'd need all new charge stations then, plus we need the 9V battery form
factor.

J

Joerg

Jan 1, 1970
0
Martin said:
We used to use Vartas, many years ago. I'm sure they have NIMH now.

Search, seems to be $7-$10 per battery.

They have a few, between 170mAh and 200mAh, but no 250mAh :-(

http://www.filmtools.com/varaculnimre.html

The capacity really made a difference when I tested various brands a few
years ago.

J

Joerg

Jan 1, 1970
0
RogerN said:
I'm considering ordering some of these:
http://www.amazon.com/pieces-250mAh-capacity-rechargeable-Battery/dp/B001CON7PS/ref=pd_rhf_p_t_1
The reviews look mostly favorable.

Two of the reviews on Amazon are a bit disconcerting. In the test below
they didn't quite reach the Ansmann battery performance but we could
live with the 10% less they delivered:

http://www.rechargeable-battery-rev...attery-tests/9v-nimh-battery-performance.html

At least the R&D seems to be in the US:

http://www.tenergybattery.com/index.php?option=com_frontpage&Itemid=1

Thanks, Roger, we will give those a shot.

?

_

Jan 1, 1970
0

Some time ago i built a 9v source out of an odd-sized cell (2/3 c maybe?)
and one of those little smps kits. After I re-located the cap to fit
inside the toroid it and the cell just fit in a 9V space. The cell was
something like 850 mAh - probably could be double that with today's NiMh
cells.

Cost was small, but you'd have to build a special dock for charging it;
obviously just shoving 9v back through the smps would not work. Contacts
on the bottom with a cap on 'em perhaps.

Even though the smps is inefficient, some decent % of 1500 mAh is way
better.

P

Phil Allison

Jan 1, 1970
0
"_" = a bleeding idiot
Some time ago i built a 9v source out of an odd-sized cell (2/3 c maybe?)
and one of those little smps kits. After I re-located the cap to fit
inside the toroid it and the cell just fit in a 9V space. The cell was
something like 850 mAh - probably could be double that with today's NiMh
cells.

Even though the smps is inefficient, some decent % of 1500 mAh is way
better.

** Way better than a 250 mAh, *9* volt battery ??

No fucking way.

9 time 0.25 = 2.25 watt hrs.

1.2 times 1.5 = 1.8 watt hrs.

...... Phil

N

Nico Coesel

Jan 1, 1970
0
Joerg said:
Hello All,

At church we are using Ansmann 9V/250mAh NiMH batteries, lots of them.
After a few years they are gradually reaching the end of their useful
life. Looking around I found they now cost about \$13 a pop and up.
Amazon even lists them for a whoppping 20 bucks. Yikes. Maybe because of
the falling Dollar.

Is there any other brand from Asia that's a good deal? I'd rather not
buy from some of the east coast photo dealers anymore because last time
I experienced, ahem, not so honorable behavior.

From my experience: at one of my former employers we found a supplier
of relatively cheap 9V recharchable batteries after some experimenting
(that was NiCd). We sold a lot of those to churches. If you are
willing to experiment a bit you could find batteries that offer the
best performance.

J

Joerg

Jan 1, 1970
0
Nico said:
From my experience: at one of my former employers we found a supplier
of relatively cheap 9V recharchable batteries after some experimenting
(that was NiCd). We sold a lot of those to churches. If you are
willing to experiment a bit you could find batteries that offer the
best performance.

Yesterday I asked our church to order some of the Tenergy batteries that
Roger had suggested. Around five bucks a pop with shipping, that would
be very reasonable if they work out. So we'll get four now, test the
heck out of them, and then if ok replace all the others.

J

JosephKK

Jan 1, 1970
0
Yesterday I asked our church to order some of the Tenergy batteries that
Roger had suggested. Around five bucks a pop with shipping, that would
be very reasonable if they work out. So we'll get four now, test the
heck out of them, and then if ok replace all the others.

I have used Tenergy before and was pleased with them. I hope your
experience is the same.

J

Joerg

Jan 1, 1970
0
JosephKK said:
I have used Tenergy before and was pleased with them. I hope your
experience is the same.

I'll let you guys know when we've had them through the paces. I hope I
remember ...

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