What to do with a bunch of slightly depleted 9V batteries?

[Dave Britten]

For the next few months, I have to give myself a 12-hour IV every night (nutrition via IV, basically; look up "TPN" if you're curious about the details). The IV pump I was given runs on a single 9V battery. I am instructed to use a fresh battery every night, and am provided with them accordingly.

It looks like the batteries have about 8V left on them once the run has finished in the morning. Rather than chuck out ~120 batteries with useful life in them, I'd like to find something interesting to use them in. Calculators, computers, portable video games, whatever. Off the top of my head, I've got a couple things that run on a 9V:

TI-30
Sinclair Cambridge Programmable
Psion Organiser II (a few of 'em)
Milton Bradley Microvision (pretty sure this uses a 9V)

What else should I go hunting for on ebay, knowing that I'll pretty much never have to buy any batteries for it out-of-pocket?

[eried]

You can connect 2 of them and make a little hand warmer for a while. Why don't you use a DC adapter for that device? 1x fresh 9V per day sounds quite wasteful

[Paul Dale]

(08-08-2014 04:28 AM)Dave Britten Wrote:  For the next few months, I have to give myself a 12-hour IV every night (nutrition via IV, basically; look up "TPN" if you're curious about the details). The IV pump I was given runs on a single 9V battery. I am instructed to use a fresh battery every night, and am provided with them accordingly.

I'd use a plug pack instead. They can be bought with a 9V battery tab.

Alternatively, rechargeable nine volt batteris are available. I'm not sure how their voltage compares with a real one -- I'd imagine 9.6 or 8.4 volts.

You could open them up and extract the AAAA batteries that are often inside. Not sure what you could use them for though.

Finally, I wish you a full recovery from whatever caused this treatment.


- Pauli

[Dave Britten]

(08-08-2014 06:08 AM)eried Wrote:  You can connect 2 of them and make a little hand warmer for a while. Why don't you use a DC adapter for that device? 1x fresh 9V per day sounds quite wasteful

I totally agree, but there are two things to consider. First, the pump uses a very proprietary power connector, and there's no way I'd find anything that fits. Secondly, though I may be a tinkerer at heart, when it comes to medical devices, I stay far, far away from unofficial modifications! Thus I'm trying to make up for the waste on the back end. If that requires buying something cool from eBay, so be it.

(08-08-2014 06:34 AM)Paul Dale Wrote:  I'd use a plug pack instead. They can be bought with a 9V battery tab.

Clever idea, but then I'd be stuck to the wall for the full 12 hours, and my bladder definitely can't take that! Th pump supports an external power supply and battery pack, but alas, I was not provided with either.

(08-08-2014 06:34 AM)Paul Dale Wrote:  Alternatively, rechargeable nine volt batteris are available. I'm not sure how their voltage compares with a real one -- I'd imagine 9.6 or 8.4 volts.

Could be an option, but again, I'm extremely reluctant to use anything besides what's given when it comes to medical devices. Particularly with something as crucial as an IV pump.

(08-08-2014 06:34 AM)Paul Dale Wrote:  You could open them up and extract the AAAA batteries that are often inside. Not sure what you could use them for though.

Yeah, I'll probably give this a try at least once.

(08-08-2014 06:34 AM)Paul Dale Wrote:  Finally, I wish you a full recovery from whatever caused this treatment.

Thanks. It's just more BS from the Crohn's disease, same thing that had me in the hospital a couple months ago writing a bunch of 48GX and WP-34S programs to stay busy/sane. Essentially, I'm unable to eat a sustaining diet for a few months, so this is taking it's place. The good news is I can redirect the grocery budget to more calculators/computers/video games. My wife will be thrilled, no doubt.

But what to do with all these batteries I'll be receiving...

[kusmi]

I would go for this ;-)

https://www.youtube.com/watch?v=8hwLHdBTQ7s

[Katie Wasserman]

(08-08-2014 09:45 AM)kusmi Wrote:  I would go for this ;-)

https://www.youtube.com/watch?v=8hwLHdBTQ7s

I was going to suggest some higher voltage experiments but not that high. The person who did these experiments is lucky to be alive he was extremely careless in almost everything he did.

Using about 15 batteries in series (since you say they measure 8 volts each) will give around 120 volts so you can power some items that you would not think of as portable, a string of old-style, incandescent Christmas tree lights for example. Neon bulbs are fun to play with using medium-high voltage DC; you can make some nifty oscillators by adding resistors, capacitors and diodes. Along the same lines, you can power some Nixie tubes circuits with these discardable batteries, but you'll need to up the voltage for this a bit.

[everettr]

(08-08-2014 03:32 PM)Katie Wasserman Wrote:  Neon bulbs are fun to play with using medium-high voltage DC; you can make some nifty oscillators by adding resistors, capacitors and diodes.

If you don't include a series resistor in the circuit, neon bulbs make great short circuits! I learned about current-limiting as a child when I poked the leads of a bare neon bulb into an electrical socket. There was sound and heat, and as the spots slowly faded from my vision, I remember being slightly puzzled by seeing how short the leads had become.

[Dave Frederickson]

(08-08-2014 06:40 PM)everettr Wrote:  If you don't include a series resistor in the circuit, neon bulbs make great short circuits! I learned about current-limiting as a child when I poked the leads of a bare neon bulb into an electrical socket. There was sound and heat, and as the spots slowly faded from my vision, I remember being slightly puzzled by seeing how short the leads had become.

As I recall my experience, it was a 2W resistor that didn't seem to have any purpose being in my nightlight.

[Joe Horn]

(08-08-2014 07:34 PM)Dave Frederickson Wrote:  

(08-08-2014 06:40 PM)everettr Wrote:  If you don't include a series resistor in the circuit, neon bulbs make great short circuits! I learned about current-limiting as a child when I poked the leads of a bare neon bulb into an electrical socket. There was sound and heat, and as the spots slowly faded from my vision, I remember being slightly puzzled by seeing how short the leads had become.

As I recall my experience, it was a 2W resistor that didn't seem to have any purpose being in my nightlight.

I first learned about electrical resistance by sticking a bobby pin in the AC socket, when I was a toddler. It melted and burned a hole in my hand. One of my earliest memories.

Back to OP: AAAA cells (extractable from 9V batts) are used in some elegantly thin laser pointers.

[John Smitherman]

Building on Katie's idea here is a link to an electronic Christmas tree kit that uses 9 volt batteries: Link

All the best,

John

[BobVA]

You definitely need a few of these:

9v Pak-Lite

[Dave Britten]

(08-10-2014 10:03 PM)BobVA Wrote:  You definitely need a few of these:

9v Pak-Lite

Those do look pretty slick. I wonder what the brightness/run-time would be like starting from an alkaline with 8V left in it.

[walter b]

Nice idea - quick and dirty position lighting. Is it rain-proof? Is there anything directing the light except the LEDs themselves?

d:-?

[BobVA]

Quote:Those do look pretty slick. I wonder what the brightness/run-time would be like starting from an alkaline with 8V left in it.

Mail me a battery and I'll tell you. I couldn't resist the red/white LED version. (You'd think I'd have outgrown my 10 year old kid fascination with flashlights by now.)

Walter: Looks like bare LED's, so I'd guess it's probably better as a close range/flood type light.