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9V rechargeable batteries and chargers?

Then you must have a very rich church :-)

But seriously, then this kind of stuff happens: We open our church to other groups, mostly for free and to commercial groups for a very modest fee or donation. Then they use a mike and put it back. Battery still in there. Now is that still good? Did they use it for a 10min pep talk or a

1-1/2h presentation? Did they turn off the mike during breaks or just put it under the pulpit?

Same for our own activities. Often a mike is used for just a few minutes, for example during the children's message, or announcements, or stage plays. In a church it is next to impossible to tally up all that so you end up throwing away lots of good 9V alkalines to the tune of a buck fifty each. We can't do that.

Now if the mfg had been smart and included a wireless batt status feedback to the audio booth this would be _much_ easier. But they didn't. Hint to all wireless mike manufacturers: Do that!

--
Regards, Joerg

http://www.analogconsultants.com/
Reply to
Joerg
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Nowadays all chargers are, unfortunately, fast chargers. Because fast sells. I wish there was a li'l switch that allowed slow charge which would be perfectly fine in places such as churches. But there usually isn't :-(

--
Regards, Joerg

http://www.analogconsultants.com/
Reply to
Joerg

I'll try to remember to give feedback in a year or so, then we'd know whether they really hold up. These batteries are not exactly cheap so they have to withstand at least a few dozen cycles. I'll never believe the 1000 cycle claims anyway, never seen one that truly did that, or even close.

With the Tenergy 9V NiMH I am not all that enthused either which is one reason for trying out another brand.

Sanyo doesn't seem to make'em in 9V. Plus we really don't need low self-discharge because they will be left on the charger at all times except when in use. Capacity is all that matters to us.

--
Regards, Joerg

http://www.analogconsultants.com/
Reply to
Joerg

Build a 1 hour timer into the mike... that's the very longest a sermon should last anyway ;-) ...Jim Thompson

--
| James E.Thompson, CTO                            |    mens     |
| Analog Innovations, Inc.                         |     et      |
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
| Phoenix, Arizona  85048    Skype: Contacts Only  |             |
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
| E-mail Icon at http://www.analog-innovations.com |    1962     |
             
I love to cook with wine.     Sometimes I even put it in the food.
Reply to
Jim Thompson

It wound up costing us probably $150 per year, but the priest didn't have a very strong voice, so failures were very noticeable. ;)

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510
845-480-2058

hobbs at electrooptical dot net
http://electrooptical.net
Reply to
Phil Hobbs

Oh, that must be a smaller church. We usually have at least three mikes going throughout two services plus an education hour. Pastor, vicar, pulpit mike, and sometimes a fourth for the DCE. Assuming two per mike per Sunday that's worst case eight per Sunday, plus on special days, say

60 sets a year, that's 480 batteries. At $1.50 that would be $720. Versus under $200 for the new Maha set which (hopefully) lasts us through two years. So we'd save $1200 over that time. That buys a ton of good food for the food closet which is always aching for more money these days. 
--
Regards, Joerg

http://www.analogconsultants.com/
Reply to
Joerg
[snip]

Wait until Obama gets reelected... then you're really going to need that food closet :-( ...Jim Thompson

--
| James E.Thompson, CTO                            |    mens     |
| Analog Innovations, Inc.                         |     et      |
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
| Phoenix, Arizona  85048    Skype: Contacts Only  |             |
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
| E-mail Icon at http://www.analog-innovations.com |    1962     |
             
I love to cook with wine.     Sometimes I even put it in the food.
Reply to
Jim Thompson

Even if money was no object, replacing the batteries after each use is a hassle. Much better if they can just pick the mic up from the charger and be ready to go. I wish I had a reasonable answer for you. All I can come up with is that it might end up worth the effort to modify all of the chargers, as horrible as that sounds. And it does sound horrible. :-(

Ed

Reply to
ehsjr

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Unfortunately these mikes have no cradle chargers. One must swap 9V batteries. However, Sennheiser has done a nice job in that you can swing them open in a way that the battery sails into your cupped hand while holding the new battery between thumb and index finger. Then plop in the new one, old one back on the charge station -> done. I've done this while crouched on the floor behind the choir so it won't disturb the service. Luckily we have a side entrance right there.

--
Regards, Joerg

http://www.analogconsultants.com/
Reply to
Joerg

LiPoly: a few% to 100% =3D [3.6V .. 4.2V]

That's 8.4V fully charged for two cells in series; 50% (nominal) for a two-stack would be 7.8V.

-- Cheers, James Arthur

Reply to
dagmargoodboat

A though if you have time for the extra work:

2 x 10440 lithiums can be packed in the same space as a 9v. Use one of those regulated (microchip make them) capacitor voltage doublers +90% efficiency (plus a bug cap for output surge current), a diode so it can be charged through the "normal" terminals and a 2.5mm recharge terminal in the base (plus build your own lithium recharger) and your done - 9v rock steady 350 - 400 ma hours.
Reply to
David Eather

That could just work. Not a whole lot of margin but maybe enough. However, we have ordered the 300mAh NiMH batteries already. I had looked at LiIon solutions but what scares me is that someone could unknowingly stick this into a regular charger. Probably the same danger with LiPoly.

There is a protection circuit in there, usually, but all this typically comes from China. And a guy in Germany has seen first hand what can happen there. A thermistor in a battery pack was economized out of the design and replaced with ... a 10k resistor.

--
Regards, Joerg

http://www.analogconsultants.com/
Reply to
Joerg

I can already see the headlines "Pastor's trousers caught fire" :-)

They do not have charge terminals and there isn't really any space to put charge terminals. These are pro-quality metal case units. Wireless mikes also don't have surge currents. They typically draw a steady

50-60mA because it's FM transmission. 
--
Regards, Joerg

http://www.analogconsultants.com/
Reply to
Joerg

[snip]

That could be quite effective if it happened during a sermon on Sodom and Gomorrah ;-) ...Jim Thompson

--
| James E.Thompson, CTO                            |    mens     |
| Analog Innovations, Inc.                         |     et      |
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
| Phoenix, Arizona  85048    Skype: Contacts Only  |             |
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
| E-mail Icon at http://www.analog-innovations.com |    1962     |
             
I love to cook with wine.     Sometimes I even put it in the food.
Reply to
Jim Thompson

Or a genuine fire and brimstone sermon :-)

--
Regards, Joerg

http://www.analogconsultants.com/
Reply to
Joerg

I didn't think the Lutherans were into hellfire and damnation.

Reply to
krw

I buy AAs at Lowes for $.20 each. I know times are tough, but there has to be at least a buck in the collection plate. ;-)

Take it out and pitch it, no matter how long it might have been used.

So don't.

The display probably cost too much.

Reply to
krw

How much do you pay for good quality 9V alkaline batteries? Duracell or similar.

That is costly with 9V cells and also not very good environmental stewardship. God gave us the earth and everything that's on it but he did not put a spare into the trunk in case we screw up with this one.

Hence our need for a good NiMH and charger combination :-)

Nope, and that is the sad part. The Sennheiser system already has a fairly luxurious display, backlit, the whole nine yards. It shows the frequency, the RF level and the audio level, so one alphanumeric string and two horizontal bar graphs. It would have been a piece of cake to add a battery alert but ... they didn't :-(

Even on the old Shure Marcad they could have done it. I mean, what's so difficult about letting the diversity lights blink? Or let the red audio overdrive LED blink. They are already there, costs nothing.

--
Regards, Joerg

http://www.analogconsultants.com/
Reply to
Joerg

True, but some of the sermons can be downright scary yet be an exact replica of what the bible says.

Some of our family are Catholic. Once we had a longer chat over the phone and they asked about the difference to us. "Well, for example, we Lutherans do not believe in purgatory because it's not in the bible" ... "Oh, ya well, they've long since discontinued that!"

I was almost laughing myself off the chair :-)

--
Regards, Joerg

http://www.analogconsultants.com/
Reply to
Joerg

You don't prefer the headline - 'Pastors preaching set the church on fire'?

I understand the objections. I would say that if you use 2 x 10440 batteries you have about 7 mm for some sort of socket. Thanks that you worked around the typos 'bug' for 'big' and 'a diode so it can be charged through' for 'a diode so it can't be charged through'

Reply to
David Eather

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