Alarm clock explodes 9V battery backup?

Hi,

Did the manual / sticker mention 9V battery or rechargeable one (7,2V) ?

The clock must have been made to use a chargeable battery. I have seen this before!

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JANA _____

Hello, This is a odd question but I have two new digital alarm clocks model: 3038 Green LED cheapos bought from wal-mart. Yesterday I set both of them up; both appear to be working fine...but last night while slepping I heard a loud POP! and saw smoke puff out of one clock I opened the battery compartment and saw the 9V battery was bloated with corrosive crap leaking out. I looked at the other clock and it is doing the same thing!!! This is a fire hazard; right? I measured the battery connector red/black wires (inside the clock) with a voltmeter and reads: 7 volts...any ideas?

-- quietman

Unless any manual (if it exists or is in readable English) says to only use a rechargable 9V, all I can say is: Cheap Chinese CRAP from WalMart. You get what you pay for.

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It should say it on the battery cover or inside the compartment.

--
*I'm already visualizing the duct tape over your mouth 

    Dave Plowman        dave@davenoise.co.uk           London SW
                  To e-mail, change noise into sound.

Forget contacting the manufacture, I doubt the Chinese firm would even care. Contact Walmart corporate and the consumer product safety commision. The cpsc.gov has an online form you can fill out. If you really are concerned about others safety, get some picture of both units and the batteries that you can send to them. If you call the cpsc on Monday, the cpsc might even want you to ship the defective units to them for evalution.

The battery is not rechargeable (normal 9V Duracell Alkline) and the clock isn't suppose to act like a battery charger. I had a electronic repair guy look at them and he said a diode was shorted which caused the power from the clock's transformer to the battery connector both clocks have the same problem. I'm thinking of buying a couple more of these to see if they are doing the same thing and then I'll take all four of them back to the store. I'll contact the manufacturer tell them about it. This is a fire hazard!!!

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quietman

Must be rechargable battery.

9V rechargeables are not terribly popular. I can't recall a single piece of equipment that uses them.

Most likely, the alarm clock had a diode between battery and power supply and it shorted causing the battery to be charged.

I would think in two brand new units that either the manufacture installed the diode wrong, or decided to cut corners and messed up the design.

That would be a neat trick to accomplish. What size hammer would it take to get the male side of the connector to mate with a male and the female to mate with the battery's female?

I'd guess a 2 lb sledgehammer would be sufficient, although you'd be likely to smash your fingers in the process. ;-)

- Mike

Take them back to Walmart and get a refund and then buy higher quality radios at Walgreeens

H. R. Hofmann

connected the battery backwards?

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Real Programmers Do things like this.
http://webpages.charter.net/jamie_5

The isolating diode is shorted, might be a solder bridge, return the clock and get a different one, or solder a diode into one of the battery wires.

Just for the record...

Kenwood/trio TR-9130 VHF amateur radio transceiver uses one for memory backup.

Regards

Francesco IS0FKQ

To charge a 7.2 volt battery, you need more than 7.2 volts. The poster stated non rechargable. I have made devices and applied a very slight voltage to the nonrechargable, so it has no drain of any type. These batteries should last years, especially carbon. My not cheap Sony has a rechargable battery inside, but it could be a cap holding a charge. There is no 9 volt replacement battery as all should be. Can you inaging how much money I have saved using the clock for over 15 years and all that worry about changing batteries. Perhaps in the posters device another battery type was specified in the design. The other clocks I have had using alks. I had to replace the battery every year or else the warning light came on. No good.

I have to replace 9 volt rechargables on a regular basis. They are in handheld pippetors. There are at least two types of rechargables, there are 7.2 volters and there are 8.4 volters. greg

I've modified all my clock radios to use one by adding a resistor across the isolating diode, got sick of the 9v being dead every time I needed it.