Rechargeable Batteries

[viking33]

The date thing is a good tip. Chris suggested it too. Funny thing is that I'm already a fanatic about dating the user doc or manual that comes with anything - computer drive, vacuum cleaner, etc.

But I've not thought of doing it with batteries, except in my cell phone 'cause it's larger and rectangular. I do believe I'll start though.

I've got an el-cheapo voltmeter around here someplace. I think I better hunt for it... Thanks Bob!

That will work fine.
I also do the date bit on user manuals and how many times do you ask yourself, now WHEN did I buy this?

[Bigaldoc]

... and how many times do you ask yourself, now WHEN did I buy this?

Not very many. I've been doing it for about 40 years now. When Billie and I first "set up housekeeping" (as they call it here in Kentucky) and bought our first appliances, TV, sewing machine, etc. I started writing the purchase date in the manuals. Been doin' it ever since.

Since the days of the internet, I also keep an email file for web purchases that goes back to 1997.

[Bigaldoc]

Yep, you're ready to freeze

Wellll, I don't what's happenin' but I'm gonna cool it until morning and see!!!

I just pulled the four AA batteries out of the freezer and put 'em in my charger. When I plugged it in, I saw the normal behavior where the four lights blink red, one at a time for a cycle or two.

BUT then something strange. All four lights are BLINKING red continuously where that is NOT the norm for this charger. Usually, after a round of blinking, one light at a time, all four come on solid red and stay that way until the lights turn green.

So, I don't know if the batteries are defunct (which I suspect), the charger is bad (I have a better replacement on order) or the FREEZING is causing this unusual behavior. I'm gonna leave 'em until morning and if the lights ain't green, I'll throw all four in the bin.

So goes another day in the world of technology...

[BobL]

Hey Al, just to step in here, since I was the original 'recommend-er' from the original thread back when...
The re-chargeable batteries I bought were Sony, with the Sony Charger. Back in April 2007 if my records are correct. At that time I recommended any rechargeable that had a rating of 2200 mah or higher. Do note that I am still using those same rechargeables that I bought back in 2007 (these are 2500 mah rated) and they are still running hard. May not last quite as long as the 2 weeks I needed them back in 2007, but they are still a workin...
From your experience, I'd say you were due for a new set of batteries...?

[viking33]

Keep a close eye on that charger unit, Al.
Might be tuned for smoke, as we used to say.
I don't know if I would trust leaving it unattended over night. The four blinking lights might be saying......warning....warning!

[Bigaldoc]

Uh Oh, I've got TWO Bob's to reply to!!!

Other Bob: I think you're right. I guess I just expected them to last longer as yours seem to be doing. Back then, I bought both 2450 and 2900 mAh, thinking I was doing a good thing. And, I guess I did 'cause until recently, they all gave me good service. Truth is, the 2900 mAh ones ARE still performing OK. I guess I'll never know if it's the charger or the batteries. But, I will have learned a little from this experience. The eight I have on order are also 2900 mAh and I WILL put a date marker on them when they arrive.

Bob Viking: You're probably right on AGAIN! Before I go to bed tonite, I think I'll rule it a lost cause and unplug the charger and file-13 the four batteries. The last thing I need is a possible fire!!!

[ChrisGreaves]

I also do the date bit on user manuals and how many times do you ask yourself, now WHEN did I buy this?

Right back at yer!
http://www.chrisgreaves.com/SUFE/How%20To%20Find/PostageStampSheetBorders.htm

[ChrisGreaves]

Before I go to bed tonite, I think I'll rule it a lost cause and unplug the charger and file-13 the four batteries. The last thing I need is a possible fire!!!

Why not make better use of your resources?
Leave the charger plugged in, but put it directly under your smoke-detector; that way, if you wake up in time, you'll know that that battery doesn't need recharging.

[viking33]

Before I go to bed tonite, I think I'll rule it a lost cause and unplug the charger and file-13 the four batteries. The last thing I need is a possible fire!!!

Why not make better use of your resources?
Leave the charger plugged in, but put it directly under your smoke-detector; that way, if you wake up in time, you'll know that that battery doesn't need recharging.

Check the batteries in your smoke detector first!

[BobH]

Sorry to be so late to this party. Blame on the iPad.

If complete discharging is the desired goal, there ought to be a device that will put a load on them to drain them. I seem to recall that we such an animal at the office 12-15 years ago for use on cell phone batteries because they were so expensive and hard to come by but we all had to be a phone call away. They probably don't bother for AA/AAA rechargables because they figure they are disposable.

Anyone else remember this?

[ChrisGreaves]

Check the batteries in your smoke detector first!

I always put my smoke detector in the freezer before going to bed each night.

[ChrisGreaves]

there ought to be a device that will put a load on them to drain them.

Wouldn't a dud charger, with a wrire connecting each terminal, drain the batteries pretty quickly?
I imagine one could do a pretty fair job with a small metal base, a wire soldered to an alligator clip.
Stand the cell on the base, hook the clip to the upper terminal?

[StuartR]

...I imagine one could do a pretty fair job with a small metal base, a wire soldered to an alligator clip.
Stand the cell on the base, hook the clip to the upper terminal?

I think you need to add a resistor to this circuit, very fast discharge is bad for any battery.

[Leif]

I imagine one could do a pretty fair job....

Under NO circumstances, short circuit a battery unless you are 100% certain it has no energy left.

As Short circuit - Wikipedia states: "A large current through a battery can cause the rapid buildup of heat, potentially resulting in an explosion or the release of hydrogen gas and electrolyte (an acid or a base), which can burn tissue, cause blindness or even death."

[ChrisGreaves]

Under NO circumstances, short circuit a battery unless you are 100% certain it has no energy left.

Hi Stuart and Leif.
Hence Bob's point "a device that will put a load on them to drain them"
Thanks for the warning!
What about a flashlight bulb in the circuit for those AA/AAA batteries?
I suspect it would be too small to be of much value in discharging a laptop battery.
What about, say, a 100W household lamp bulb?

[Leif]

Personally, I do not think it a good idea to completely discharge a rechargeable battery - i.e. to the point at which there is zero voltage across its terminals - and particularly not for an extended period.

Devices that use rechargeables, such as mobile phones and laptops, have built in circuitry to switch off when the battery voltage drops below a certain level, and this is to protect the battery as much as anything else. Torches that use rechargeable batteries can have either a filament bulb or LEDs. Because a filament bulb is essentially just a resistance, leaving it switched on indefinitely can terminally damage the battery, but LEDs require a minimum voltage to operate and can therefore never completely discharge a battery and it should be safe to leave them on. Other devices, such as wireless mice and radios, will have a minimum working voltage which may or may not cause total discharge of the battery. In other words, if the device has no battery monitoring intelligence, it can be easy to damage a rechargeable through over-discharge.

So, for example, leaving a laptop running on its batteries until it switches itself of would be the ideal level of discharge required for that battery in my view.

Having said that, you will find people that have their own preferred methods, and if you can use them to good effect, then good! Bear in mind though that there is more than one kind of rechargeable battery, and they all have differing properties. If you know the type, do a Google for "get the best out of rechargeable <battery type> battery" and you'll come across articles like How To Get the Most Out of NiMH Rechargeable Batteries - Tested.

[Argus]

Around here the most popular chargers seem to be either timer controlled (the cheaper ones) or with a combination of timer and "negative delta V cut-off" (for slightly more adv. and faster chargers), all often combined with some trickle charging. (Negative delta V, i.e. a drop in voltage from peak, fully charged.)

[stuck]

The positive electrode is typically made of nickle

I hope their advice is better than their spelling.

Ken

[Leif]

The positive electrode is typically made of nickle

I hope their advice is better than their spelling.

Ken

Well, according to Wikipedia, "Nickle, another name for the European woodpecker", so perhaps they're recycling Piculets that have been placed in the freezer overnight for electrodes?

[ChrisGreaves]

perhaps they're recycling Piculets that have been placed in the freezer overnight for electrodes?

:knockonwood: !