Excal Users FYI

[Bootyhunter1971]

I was getting ready for a trip (6 hours away, 5 day stay) at the beach so I have 2 Excal Battery packs. Charged the one on the detector then put the spare on the charger the night before the trip. Got about 3 hours into my drive and remembered the charging battery , put the thing on charge Monday afternoon, got it off the charger when I returned home the following Saturday night around Midnight. Happy to report that I didn't find any damage and the charger wasn't even very hot. Put that battery on and have hunted an hour with it and it worked as usual. Still have to see how long it will last though but overall looks to be no damage. Do I advise doing this? No, but just thought I would share the results of this "accidental" experiment. HH to all.

 

[Killer Angel]

Glad no damage done. And lucky for you the metal detecting industry isn't up with some others in battery technology. Had that battery been a LIPO your house woundn't have been there. More than one RC enthusiast had found that out the hard way.

 

[Aurora64blue]

Hi Captain L3

For my Tesoro Cibola, I use rechargeable 9 volt batteries.

Now since the 9 volts batteries won't trigger the auto off on my battery recharger. I decided to plug the main charger into a pre - set timer, this way the charger will get automatically turned off by the separate timer that the battery charger plugs into.

It's the same type of timer that you might plug a free standing light into, in order for them to come on and off when your on a vacation, or when you want a light to come on when you wake up in the morning.

I normally set it for 8 hours, this way it stops the battery from getting fried when you forget about it and suddenly remember that you had a battery recharging 2 days later!

A reasonably cheap solution for what may be a fairly common occurrence. $3 - $5 bucks at any Wallmart store would probably cover it.


Cheers, and good hunting!

Ralph

 

[Buried Crap NJ]

Th reason for no damage is that Minelab and other use a Thermistor very cheap way to do this!

Thermistor

Thermistors are circuit devices whose resistance varies with temperature. PTC thermistors have a Positive Temperature Coefficient in that their resistance increases gradually with temperature and over a limited range the resistance can be considered linearly proportional to temperature. Similarly NTC thermistors have a Negative Temperature Coefficient and their resistance decreases as temperature increases. These components are used extensively in monitoring and protection circuits to provide a voltage analogue of temperature or in control circuits designed to provide temperature compensation. They may be used to terminate the charge (dt/dT) or to disconnect the battery from the charger in an over-temperature condition when the temperature cut off point is reached, or they could be used to turn on cooling fans.

In some applications the thermistor may be the only means of communication between the battery and the external world.



Thermistors can also be used by the charger to determine starting environmental conditions and prevent charging if the battery temperature is too low or too high.