9v battery terminal blanks?

As Michael pointed out, the same caps that Duracells ship with are available in aftermarket. Personally, I just use a piece of gaffers (duct) tape, line the cells up--terminals down, adhesive side up--then fold the tape down over the sides. That's enough to keep them from shorting together. Put in a drawer or box, they won't short to anything else.

YMMV...the goo from the tape is sometimes an issue.

jak

Now if it's AA/AAA/CR123 cells you want to protect, there are nice little soft plastic snap boxes available that work fine. Dealextreme sells a set of 3 4-cell AA boxes for < $2.50. Pricey for a few bits of plastic, but that includes worldwide shipping. I use them for NiMH AA cells. You often get them for free when you buy a set of 4 cells.

Just out of curiosity, what are you using that requires a 9V rechargable battery? Something special? Most occasional-use meters and such like are better off with a 9V primary cell because of the low self discharge rate of primary cells compared to NiMH.

Best regards, Spehro Pefhany

--
"it's the network..."                          "The Journey is the reward" 
speff@interlog.com             Info for manufacturers: http://www.trexon.com 

To be honest, I don't use them for anything. My comments referred to alkalines used in wireless mics and other sound equipment. I save the used batteries in the manner suggested above. 9v's are expensive. While I wouldn't use them again professionally, we change them at almost every opportunity, since the expense is trivial compared to a dead mic during a show or presentation. As such, they are still useful for less demanding applications.

I also wouldn't use rechargables for the application; but the size, shape and intent are close enough for the method to be useful to the OP.

jak

Surely the client effectively pays for them?

But if you're using decent quality batteries and equipment, the life should be pretty consistent. With mine, it's 9 hours so I change at 8. If I were using them for an all day presentation where they could only be changed at say the lunch break, good rechargeables *might* be worth it. Assuming your mics have an SMPS that can work on the lower voltage.

But as I said earlier, 'pro' batteries bought by the box already come with a clip on protector. Or do in the UK. And are cheaper per unit than buying retail - unless you're willing to use no name stuff. At the moment I'm using Energiser.

--
*There are two kinds of pedestrians... the quick and the dead. 

    Dave Plowman        dave@davenoise.co.uk           London SW 

When I say they're expensive, I'm speaking as a consumer. A card of two name-brand 9v's might be as much as $8 in a convenience store. That's a lot to pay for a backup battery in an alarm clock (the usual destination for my used cells), or a toddlers toy. Servicable cells are a perk of the job. I never buy them, either way (unless jobs with 9v's haven't come my way lately). Professionally, the client pays. Personally, I get free batteries.

Either way the cost (to me) is trivial.

The breaks don't always come at 8 hours. So, as you say, at lunch I'd change them, depending on the projected balance of the presentation. I'd also watch the reciever battery indicators like a hawk if they started to get low. I've been known to sneak up and change them on the fly.

I've never bught (my clients haven't, actually) anything but Procells. I don't--and I don't allow anyone to--put the protectors back on the cells, or put them back in a used box. In the box--or protector on--means 'new battery' to me. Too much trouble to keep track during the heat of battle. If the stagehands or anyone else want the used cells, they need to get them out of my sight.

I don't have time to check (or recharge) used batteries. I do check the mic's indicator whenever I change out the cells, though. I've never gotten a bad Procell; but there's a first time for everything.

jak

jakdedert wrote: I've never

I have! several times. PP3`s suffering sudden infant death - I always let radio mikes run for at least 15 minutes before a show where I can. I`ve never had a faulty AA, but as you say there`s always a first time. and I never ever use rechargables in radio packs.

ROn(UK)

Why? [if you wouldn't mind a newbie question...]

--
John English

My answer would be is you can virtually guarantee the performance of a decent make alkaline. And I sometimes use a great deal - my personal record for number of radio mics is 38 at once. It really is rare to get a faulty battery.

Trouble with rechargeables is they don't maintain the same performance throughout their life - which makes knowing when they must be changed rather hit or miss. Plus the fact that most give little warning of running out - unlike an alkaline - due to the different voltage discharge curves. So what might be a benefit on a high power demand device like a drill etc is a liability on a low current one.

Of course if you know they will only be used for a short time - like say a church service - rechargeables can and do make sense. But this isn't usually the case for film, TV and conference etc use.

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*Do infants enjoy infancy as much as adults enjoy adultery? 

    Dave Plowman        dave@davenoise.co.uk           London SW 

Then use the new type of NiMH, the pre-charged ones which don't lose power sat on the shelf. Take them out the packet and they are as good as alkalines. Only keep them for a fraction of their life if you want a nice long charge, and put them in a trickle charger when not in use.

--
http://www.petersparrots.com    http://www.insanevideoclips.com    http://www.petersphotos.com 

"It is generally inadvisable to eject directly over the area you just bombed." - U.S. Air Force Pilot training manual

There are three problems with them. The first is that they are supplied charged, but only about 80% charged. While they take longer to discharge on their own, if they sit on the shelf for a year or so, they very well may be flat.

The second is that they do not reach their full capacity when recharged until they have been through 3 or 4 recharge cycles. I have found with the ones I bought it took even longer, sometimes 10 cycles to get any useful life out of them.

The third is that they have a higher internal resistance which limits their output current. That is why the rechargeable alkelines that came out around

1995 never really took off. They were lower in capacity to the disposable ones (about 80%) to allow room for expansion, and they did not put out the current that nicads or regular alkelines did.

They also do not charge as fast. I charge mine in a 7 hour NiMH charger, but have to do it twice. Using the little fixed rate charger that came with a set, I have to charge then for at least 24 hours.

Geoff.

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Geoffrey S. Mendelson, Jerusalem, Israel gsm@mendelson.com  N3OWJ/4X1GM

Geoff,

Do you have any info that indicates that they can't put out as much current and/or have higher internal resistance (over time) compared with alkalines?

I have been using the Hybrio hybrid batteries in a Canon SX100IS digital camera for about a year now and I haven't noticed anything problematic about them. They last a LONG time without any special conditioning. I use a Maha MH-C401FS charger (set to 'slow').

I've used alkalines in several different cameras and have had horrible results with them.

Bob

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== All google group posts are automatically deleted due to spam ==

Sorry, I said two different things in the same paragraph and may have created some confusion.

First the slow self-discharge rechargable batteries have a higher internal resistance and lower output current than the "regular" ones of the same chemistry.

Therefore "slow" NiMH batteries have a higher internal resistance, lower output current and longer recharge times than regual NiMH batteries.

"Slow" alkeline batteries have a higher internal resistance, lower output current and longer recharge times than regular alkeline batteries.

I mentioned the alkeline ones as their high internal resistance was a deal killer for me. I could not use on HT's (handheld radios). They worked fine with 1 watt output (low power), but on high power (3-4 watts), they failed.

Going back to the NiMH batteries, I can't say how well they will hold up over time. I only use them on MP3 players that take a single AAA battery. So far it has not been good, the first batch to almost 10 cycles to have any usefull capacity. It may also have been my fault, because I charged them with the included charger which needed 24 hours or more to charge them.

The second batch has been charged only with a higher current charger and they seem fine.

Note that the players are low current devices, they discharge at about a rate of 100ma or less.

All alkelines have a higher internal resistance, which is probably why you have the problem with them. If you are a camera buff, that was one of the two differences between the Canon T-90 and EOS-1. The T-90 used AA batteries, the EOS used lithium. Canon was unable to get the current they needed for all of the electronics in the camera from AA batteries.

Geoff.

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Geoffrey S. Mendelson, Jerusalem, Israel gsm@mendelson.com  N3OWJ/4X1GM

Then how come I charge them in 15 minutes in a Uniross rapid charger?

What are slow alkaline batteries? No alkalines self discharge, so why ake slow ones?

I once got a large batch of dud NiMHs. They were non-slow Uniross batteries. They functioned normally for about 3 weeks with a few charges, then started self discharging so rapidly I couldn't leave them on a shelf for 2 days!

There are Lithium AAs.

--
http://www.petersparrots.com    http://www.insanevideoclips.com    http://www.petersphotos.com 

When is it ok for a man to hug another man? 

There are 1.5 volt lithium batteries, such as AA's. They are rare, and have extremely long shelf life, but I have never seen specs for discharge rate, etc.

The only ones I have ever seen were packed with a fan powered gas mask, but I think you can get them if you shop around.

Considering the shelf life of alkeline batteries sold here is less than a year, even the "name brands". It's almost a moot point. We no longer get any batteries from west of us, they all come from Korea, "China" (inside the PRC), Singapore or Hong Kong.

Even the Japanese brands (Sony, Panasonic, Toshiba) are made in China, and so are the famous US brands (EverReady, DuraCell). The only one missing is Ray-O-Vac.

Geoff.

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Geoffrey S. Mendelson, Jerusalem, Israel gsm@mendelson.com  N3OWJ/4X1GM

Search for lithium aa

There are loads of name brands.

LESS THAN A YEAR?!?!?! I have Duracells with a use by date of about 4 or 5 years in the future.

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http://www.petersparrots.com    http://www.insanevideoclips.com    http://www.petersphotos.com 

In light of the Madrid bombing, France has raised its terror alert level from "run" to "hide."   

So do I. They rarely last more than a year before they leak, and some brands even less. Before they changed from some anonymous Chinese manufacturer to GPT, the Office Depot brand sold here lasted 3-4 months.

Geoff.

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Geoffrey S. Mendelson, Jerusalem, Israel gsm@mendelson.com  N3OWJ/4X1GM

Ray-O-Vac is now called Energizer, i thought you were on the cc: of the memo.

An awful lot of the 'Duracells' you'll find in discount places, markets, etc. are chinese fakes. A genuine Procell PP3 has six cylindrical cells which look like a small AAA cell. The ripoffs I`ve seen have flat cells. You can barely tell the difference from external appearances alone - the price should be your guide.

Ron(UK)

They are actually AAAA cells.....

jak