Battery Drain Mystery

[Ron P]

I have in my home a Microsoft wireless keyboard which uses 3 AA batteries. It transmits to a nearby receiver which is connected to a USB port on the computer. When the keyboard was new, the batteries would last for 7 or 8 months. For some strange reason, I'm now changing them monthly.

Recently, I was away for a week and the system was completely shut down. When I returned and booted up, the keyboard was lifeless. I tested the batteries, and they tested completely and totally drained on my meter. That's unusual, because they usually test just weak when I replace them. So, while I was gone and the system was off, something drained the batteries completely.

At first, I assumed it was the keyboard, so I replaced it with another one of the same model, an older one that I still had on hand. Same result, one month. Does this make sense to anyone? Thanks.

[Jim Yanik]

"Ron P" wrote in news:hrusec$m1h$ [e-mail]:

maybe a stuck key that causes the keyboard to constantly emit the IR signal? Or something pressing a key.... something laying on the KB? Or dirt/crud causing leakage that makes the KB emit the IR signal constantly. Idea;try using a digital camera to view the IR emitter to see if it's on when there's no keys depressed. Press a key to see what happens that way,too.

Maybe you should switch to those pre-charged NiMH rechargeables. They hold their charge much better than ordinary NiMH cells. Then you can recharge them every so often and not buy so many alkaline cells.

as a last resort,you could clean your KB in the auto dishwasher(alone,not with dishes..) and dry -thoroughly- with a hair dryer. use a gel detergent,not the abrasive powder detergents.

[Tony Hwang]

Hi, It may not be KB problem.

[Bob F]

Any good reason to use a wireless keyboard? They seem pretty pointless to me for most desktop usage.

[AZ Nomad]

The KB is the only device connected to the batteries and is solely responsible for battery drain. Like it or not, it's time to switch brands.

[jamesgangnc]

I use logitec's bluetooth wireless keyboard and it has an on/off switch. You can turn it off when it is not being used. It has a mouse pad on it as well. Great for use in an easy chair or couch. Works with my ps3 as well.

[Nonny]

I'd replace the batteries. Test the battery theory by just sticking in alkalines and seeing how they last. Just don't try recharging them. Most rechargeable batteries have a lower output voltage than alkaline batteries and as they age, it gets even lower. My guess is that the rechargeables in your keyboard are getting tired.

[ransley]

Good idea, My camera and digicam sees IR, that is how ive tested remotes that were dead.

[Ed Pawlowski]

I like mine and I'd never go back to a cord. Easily moved out of the way when I need more open space. YMMV

[HeyBub]

Rig a milliamp meter between the battery and the keyboard. See what's going on.

[Ron P]

Thanks, but I've always used new alkalines, not rechargeables.

[Ron P]

How is this done? I just now tried pointing my camera at the keyboard and hitting some keys. I didn't see any change in the display.

[greenpjs]

Many of them are RF (radio). There is no IR to see. All I can think of that would affect both your current as well as the older replacement keyboard are leaky capacitors that cause more current drain than the design called for. If that's it, it would be age related rather than usage related. Or, as others said, someone places something on your keyboard that presses a key continuously. You probalby would have noticed that. Good luck.

[J Burns]

Could the batteries be from a batch that was at some point stored in a hot environment?

[Ron P]

It is old, maybe 7-8 years, and you're right, it is RF. I should have realized that. I should probably get a new one, but I've yet to see one with a special key assortment/selection that I like as much. Plus, the Windows 7 drivers work well.

[ransley]

..

Rf ok , it wont work sorry I was thinking an IR led. could it be transmitting continously from a stuck key, maybe a real cleaning could help.

[Tony]

You tried another keyboard and the same thing happens? This is really odd unless it is a common problem for that model keyboard. Do the batteries go into the keyboard itself or another device?

[Jim Yanik]

"Ron P" wrote in news:hrv8up$usv$ [e-mail]:

you have to find where the IR port is. Should be a dark plastic window somewhere,most likely on the back edge of the KB.

You can check your camera's IR response with a TV remote. If you can't see the TV remote's LED with your camera,then the camera has a filter that blocks IR,and will not work for the keyboard test.

[Daniel Prince]

Rechargeable batteries are not a good choice for his keyboard because it uses three cells. If he leaves the rechargeable cells in the keyboard until it no longer works, one of the three cells will be reversed and ruined most of the time.

Some devices are designed to use rechargeable cells. They shut off when the voltage drops to around 1.0 to 1.1 volts per cell. Devices that use just one or two cells can not reverse cells.

-- I don't understand why they make gourmet cat foods. I have known many cats in my life and none of them were gourmets. They were all gourmands!

[Tony Hwang]

Hi, Keep in mind KB is two way device. I mean it is I/O device. Mostly input to the system but output from system to KB as well.