Nine Volt Battery Mystery

[reddirtfisher]

Recently I found a 9 volt battery in some of my stuff. I tested it and it read 9.5 volts. I used it in my Compadre on my last hunt. About 10 minutes into the hunt,.... the detector went crazy !!!
It was acting like the battery was dead. I tested the voltage again and it still read 9.5 volts. So, I replaced it with the standard issue Panasonic 9 volt that Tesoro sends out. I put it in and turned on the detector and everything was normal again. What the heck??? The battery that I first used is called the Kidde "Gold Peak" 9 Volt Battery for Smoke Alarms No. 1604P. What do you think happened? Was it the extra 0.5 volts causing an overload? Some of you tech guys should know. Thanks RDF

 

[88junior]

I think it may be dropping voltage when put under a load from your detector .5 volts is not enough to cause an overload.

 

[wheatymike]

That or it was not in good. My Vaquero acted silly like that one time and the battery was not in good.

 

[tvr]

A standard 9 volt alkaline battery when brand new, should read 9.6 volts. 9.6 volts will not overload your detector. Many of the rechargeable 9 volt batteries that work with the detectors are at only 8.4 volts when fully charged.

Like mentioned above, either the battery was bad (couldn't deliver the current; dropping voltage under load) or the connection to the battery was not good.

Smoke alarms are very low drain for a long time. Metal detectors use more power (current) for a shorter total battery duration. I have one detector that does not perform well with Duracell batteries; it likes a battery with a little more instantaneous umph. Everready batteries make it happier and that detector burns through a new set of 9 volt Everreadies in about 8 hours of detecting.

The Duracells have worked just fine in the Tesoro detectors I own; Cibola, Tejon, Compadre and Sand Shark. I suspect any brand name general use alkaline battery would do well in the Compadre. Why do I mention Duracells? The nearest big box store sends out coupons and sells them in bulk for prices that are much better than what I normally find alkaline batteries on sale for. About two years ago, one of the home / construction stores had Panasonic batteries that they were nearly giving away. Those performed just fine too; except in that one detector that likes the Everready.
Cheers,
tvr

 

[John LA]

n/t

 

[TabMagnet]

I was tinkering with an old Coinmaster recently.. and replaced the AA batteries. Then I put in a 9 volt Duracell that was not new but still showed 9.5 volts. The battery meter showed it at about 40%. I replaced it with an Ultralife 9 volt lithium industrial model. It is slightly used but still shows 11.1 volts. Shows 100% on battery test. Anyone ever use something like this... at first I didn't think about the lithium aspect or the 11 volt issue.. but maybe this isn't a good thing? I haven't used the detector other than to test the G.E.B function on the bench.

 

[Rainyday101]

You can't test a battery with just a voltmeter. The battery has to be under load when tested to get an accurate reading. The battery will read high unless a load is placed on it. A battery tester will test the battery under load and you can get one at Radio Shack.

 

[TabMagnet]

I purchased a new Duracell 9 volt and replaced the Lithium 9 volt. The machine now has significantly deeper air readings on the bench. So there must be an over load of some kind with the Lithium industrial battery. Since you can't test batteries with a volt meter I would think that the higher voltage readings I took must be discounted and the issue being with the Lithium.

 

[foiled again tab hunter]

n/t

 

[reddirtfisher]

OK, I went and got a new Everready and a new Panasonic 9 volt. No problems with either one, ...but believe it or not I am getting about an inch more air test depth with the Panasonic. It is the same kind that Tesoro sends out with their new metal detectors. Maybe Tesoro knows this?

 

[tabman]

Reddirtfisher did the Compadre's battery checker give any indication that the battery was weak by giving a shorter tone when you turned it on?

tabman

 

[reddirtfisher]

The battery test on the Compadre was fine,...nice and long blast. I am beginning to think that the smoke alarm battery was loose in the compartment. It looks a little slimmer than most 9 volts and it popped in real easy.

 

[tvr]

but believe it or not I am getting about an inch more air test depth with the Panasonic.

Thanks for that observation. I will get some Panasonic's and try them in the HH Pulse ... (the detector that does not like copper tops).
Cheers,
tvr

 

[Ken/CO]

Here's the answer to the mystery:
Any battery operates with two factors; with Current and Voltage.
The battery may measure the proper Voltage and you would think it's OK.
But the Current may be to low to operate your detector.

Not all battery testers measure Current, just Voltage. And if they claim to measure the battery Current under load,
it may not be accurate. That is a different test to measure the Current accurately.

So if the battery measures the Voltage OK, but doesn't operate your detector properly, the battery is bad.

 

[tabman]

This was in my email today.

http://www.youtube.com/watch?v=Y_m6p99l6ME

I wonder if it's true. Has anyone tried the bounce test?

tabman

 

[reddirtfisher]

Wow,...sure enough,.... the 9 volt for the smoke alarm bounced all over the place while the new good one did not bounce. Who knew

 

[CWnut]

yeah, that looks like a tried and true method...but seriously, i will look into it a bit more

 

[Ken/CO]

Tesoro is aware that some of the 9 volt batteries that they send with their new detectors are bad.
The voltage checks out, but the current is insuffieient which is NOT measured on a standard battery testor.