rechargeable 9v battery

[sqwaby]

Rechargeable 9v batteries are available in different rating of 7.6volt, 8.4volt and 9.6volt. and various mah ratings. Obviously you want the highest mah, so that is not a issue. I emailed Tesoro technical about the voltage ratings though. Their reply was that the 8.4v and or the 9.6 would be ok. They did say that with the 9.6v there might be a small increase in speaker volume but other than that its fine to use. Just wanted to pass this on as some people have discussed switching to rechargeable batteries.

 

[MatthewS]

This is because the Tesoros, and many other detectors regulate the voltage internally to a much lower figure that you supply it with.

That said, the regulator would like to see at least a volt higher than it's intended regulation. For the sake of the battery meter(s) on any models reading correctly, try and feed it 9v. If you feed it less your meter readings will be off to begin with, but will still indicate low voltage properly, so no harm there.

The MAH rating is essentially the amount of current you can demand from the cell for a period of one hour before it reaches 80% of its cell death. Obviously the higher the rating, the longer the runtime in the same unit.

You will not find a lot of 'true' 9v rechargable cells on the market today. My favorite is the PowerEx 9.6v 230mah units. You can find them on ebay, etc. be advised though that you will need a charger capable of the extra voltage they want to peak charge. I run them in my prism 5, killer batteries!

- Matt

 

[JHM]

I tried the 9.6V and liked it really well

 

[chuck101]

Don't discuss batteries here,all tesoro guy's,more so with skiwhiz,they like, AK batteries only,hay matt,were do you get the prism 5 charger.Chuck.

 

[MatthewS]

The prizm has no charging jack, and I didn't add one. If you meant charger for the batteries? I have a stand alone charger that does all battery types and allows me to set the peak voltages. It's good up to 12v. They sell a speed charger for the PowerEx batteries on Ebay though.

- Matt

 

[chuck101]

Thanks,matt i got you now,i now have all powerex nmh batts for both of my detectors,but i have the large,charge all,UltraLast charger,but i can not set peak volts,i am going to check about the peak volt charger for my 9.6v,thanks for the tip!.Chuck.

 

[sqwaby]

Thanks for the input MatthewS, I'm looking at getting the lithium polymer batteries with a 520mah rating. Should give a lot of hunting time. I switched my cordless tools to the lithium type about 2 years ago, I'm very impressed with them, I don't think I'll be buying Nicads or the others again.

 

[MatthewS]

I believe you meant li-on or lithium ion... Lithium polymer (li-po) is a beautiful animal that I am very intimate with. But it is greatly misunderstood and not suitable for this application. The one common they have though is that the cells are rated @ 3.7 volts each peaking off at about 4.2 when full charge. When packe are built using lithium cell thechnology you will notice the voltages can all be divided by 3.7. A 2 cell in series can make 7.4 volts averaged, and a 3 cell series configuration can make 11.1v respectively. Unless the market demands a 9v li-xx battery in that form factor, you will not see it. Look at the voltage ratings on any of your lithium cells, or even your cell phone battery. 3.7 volts or a multiple of it.

Although there are several forms of lithium technology, the li-on mentioned above that you use in your tools will not be making it's way into a 9v battery anytime soon. So don't get your hopes up

- Matt

 

[tvr]

There are a number of chargers available that auto sense voltage and capacity and set up peak charge for a large range of cells and cell packs for both NiMH and NiCad. The one I have is about 8 years old now and it is possible to damage batteries with it if not set up correctly. I got it to charge battery packs for electric powered model airplanes. Since then the prices have come way down and the algorithms for automatic peaking the batteries and making sure you don't charge too fast or to too high a peak have gotten much better.
tvr

 

[MatthewS]

I agree. I use the triton charger for model RC for everything. The point I tried to make was that some off the shelf autochargers for 9 volts, etc won't supply a high enough voltage at the taps to peak those particular cells. Grade has nothing to do with it either as I have a cheap harbor freight multi-cell charger and it supplies 14v to the 9v taps during a charge cycle. The other concern is 'fasle peaking' when you charge high rate. The later is why I recomended the fast charger made by PowerEx for those batteries. They peak charge very fast without fasle peaking when using this charger because it's designed around the cells chemistry reactions. For low charge rates, a lot of off the shelf chargers will do. I would just verify the output voltage at the taps is sufficient. For anyone curious, you need to measure the voltage at the taps while you have the battery installed in charge mode.

- Matt

 

[tvr]

Matt,
Yes!!! Good follow up ... a generic 9 volt charger may only be able to fully charge the 8.4V and not the 9.6V batteries, measuring it will let you know what you have. .
tvr

 

[SkiWhiz]

Don't discuss batteries here,all tesoro guy's,more so with skiwhiz,they like, AK batteries only,hay matt,were do you get the prism 5 charger.Chuck.

Thanks for the compliment Chuck. I'm proud to be called a Tesoro guy!!! I have nothing against rechargeables, I just stated that one nine volt alkaline battery lasts a long time in a Tesoro so I don't feel the need for a rechargeable. But if anyone wants to use them thats great too. Steve.

 

[chuck101]

Hay Skiwhiz you know i just had to mention your name today!,seen your ordeal with brand x detector,at least you tried!,good infor about batteries,matt is a battery man!,liked the way he knew the only way to really know for sure what true otput of charger is,by measuring volts with bats in charger!,because then the charger is under a load,if measured not in charger, the charger is not under a load,good job MATT.Chuck.

 

[MatthewS]

Steve,

There is nothing wrong with that position. But allow me to attempt to appeal to your inner sense of reason and logic, with math and money.. I am using the PowerEx just as an example.

- Duracell alkaline 9v battery - $2.99
- lasts 20-30 hours in your detector, then you toss it.

- PowerEx 9.6v rechargable - $13.99 shipped to your door
- Lasts 22-32 hours in your detector, then you recharge it.

Now assume the initial investment of 32.99 to have a 4 port PowerEx charger shipped to your door as well, thats a total initial investment of $46.98. The absolute WORST your going to do with that battery is 500 charges. The actual lifecycle is on average about 1000 charges. So now we have;

- Powerex package - $46.98
- Reuse the battery 500 times
- Replaces 500 Duracells

- Cost of 500 Duracells - $1495.00

- 500 hunts @ 20 hours, worst case = 10,000 hunts.
- 10,000 hunts @ 20 hours, worst case = 200,000 hours of detecting.

So basically, you pay $46.98 and you never buy another 9 volts for that detector for THE REST OF YOUR LIFE...

$46.98 will get you about 16 hunts buying Duracells. Thats 320 hours of hunting, worst case. If you think your going to live to see more than 320 hours more hunting, it's cheaper to buy the PowerEx package now and get it over with.

Because of this simple math, I no longer buy Alkalines for anything other than emergencies. I keep a stock of C and D batteries just in case the SHTF one day and the power outages are greater that the expected life of the rechargable. Rechargables lose their appeal when you no longer have power to recharge them with

Think it over..

- Matt

 

[chuck101]

Thanks MATT,and if detector manufactures would take a break on the I D SCREEN, and instead use that large screen area available,could embed small solar panel in that area,for hunters walking and hiking,such as a gold hunter,hiking to distant hunt sites,detector would have a chance to recover charge while hunting!,think of the possibilities!,some hunters have to hike distance,and not having to carry all those battery's would be great!.And the small solar panel would not be to big or heavy,something like calculator panel x 3 or 4.Chuck.

 

[MatthewS]

Thanks MATT,and if detector manufactures would take a break on the I D SCREEN, and instead use that large screen area available,could embed small solar panel in that area,for hunters walking and hiking,such as a gold hunter,hiking to distant hunt sites,detector would have a chance to recover charge while hunting!,think of the possibilities!,some hunters have to hike distance,and not having to carry all those battery's would be great!.And the small solar panel would not be to big or heavy,something like calculator panel x 3 or 4.Chuck.

Impractical... Nobody manufactures a product and gives up a feature for something you can have second hand - Portable solar battery chargers.

If your that concerned about green energy, buy a solar battery charger and set it up at home.

- Matt

 

[sqwaby]

Matt, just to clarify the 9v batteries I found on line For my Tesoro are lithium polymer not the lithium ion. The lithium ion are the ones I use for my corless tools.

 

[bayoukid]

you're not talking about fire alarms systems not backed up by constant recharging.

Today's rechargeables have rendered alkalines totally obsolete for most applications.

My Tejon uses AA's and the rechargeables last about 3 times longer per charge than fresh dollar store alkalines.

I've used fast charge systems and the over night setups and they both work equally well.

Rechargeables are the only way to go for metal detectors.

--kid

 

[MatthewS]

Matt, just to clarify the 9v batteries I found on line For my Tesoro are lithium polymer not the lithium ion. The lithium ion are the ones I use for my corless tools.

I see that now, apparently I was alseep while they snuck this into the market! But you need to heed my footnotes on the technology and here's why not doing so bites you in the rear.

http://www.batteryjunction.com/ipowerus-9v-500.html

For example. Now scroll down to the description and look under;

 

[sqwaby]

Well I have to ask since you make a good point about the volitale nature of lithium polymer bats. Is the lithium ion a better choice or is it the same. Thanks for all the info. Sqwaby