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:usaflag:Dual Field Recharge-able Battery Mod!! :thumbup:
- Thread starter Cupajo
- Start date
imalookin2
New member
Lots of guys use AA rechargeable's. I do not like them since most do not give you 1.5 volts. Most are 1.25 volts. Even with a mod pack custom made you will be opening the latches more often. A loss of depth becomes apparent on my DF after 20 hours on good Duracell batteries. The first sign is when you dig a beach target and kick it on the sand it disappears or gets weak. Your machine will work with less than 1.4 volts on each battery but will suffer.
My buddies who do charge batteries charge every hunt or two. I don't want to open my DF latches that often. It is just not what I do with my DF but you may want to. I buy batteries and change them every 20 hours or less.
My buddies who do charge batteries charge every hunt or two. I don't want to open my DF latches that often. It is just not what I do with my DF but you may want to. I buy batteries and change them every 20 hours or less.
My experience is much the same as yours and that is why I am looking for a way to create a custom battery pack that will mount in a water-proof compartment attatched to the DF.
Then there is no need to open the detector housing to access batteries.
I also am searching for such an enclosure that would be suitable for the job. Excal battery units have been suggested, but I would rather use a smaller, boxier unit if I can find one.
It is a very worthwhile project if it can be put together.
Thanks for your insights and reply,
CJ
Then there is no need to open the detector housing to access batteries.
I also am searching for such an enclosure that would be suitable for the job. Excal battery units have been suggested, but I would rather use a smaller, boxier unit if I can find one.
It is a very worthwhile project if it can be put together.
Thanks for your insights and reply,
CJ
Critterhunter
New member
I've found in various devices for me that running 2500ma or larger capacity nimh AAs in them actually gives me much more run time than an off the shelf non-rechargeable store bought battery. The capacity of nimhs these days is pretty amazing. In various tests on the web, some claim in general a good high capacity nimh can provide up to 4 times more run time than store bought non-rechargeables. While much longer run times is well known in high current applications, there is some debate about a nimh's run time compared to non-rechargeables in low current applications.
For me I still seem to see longer run times with them even in low current applications. Shoot for the highest capacity (2500 or north of that) and you'll probably find either virtually no difference in run time that you can tell, or maybe even much longer run times. For instance, in my digital pocket camcorder my 2500ma Energizers give me more run time than good quality Energizer non-rechargeable batteries. I've never actually timed the run time but it's obvious they are giving me more run time when doing video recordings and such.
But, there is one string attached to that. Nimhs or nicads self drain in storage. For that reason run time may be effected if you don't frequently use your detector. If you are considering nimhs, there are now brands that claim low discharge for long storage when sitting on the shelf. Make sure you surf the web and see which passed various tests on this, because some have not lived up to their long term storage claims.
Modern detectors use voltage regulators to provide the circuit board with a steady, constant, non-changing voltage in order to keep things in proper specs. That means it doesn't matter if the voltage is say 10 volts or 12 volts for example, as the circuit board is still only going to see say 8V. The only time it *might* be possible to see a performance flaw is when a battery is so weak that it's voltage is sagging up and down under high power drain moments for split seconds at a time, but in fact high capacity nimhs or nicads have a much more better ability to handle higher amp draws than non-rechargeable batteries.
If you are going through the trouble of building an external battery box and using a custom battery source, I would look into lipo battery technology. All the rage in the RC crowd. MUCH lighter and smaller than the equivalent capacity in a nimh pack. I run a $7 three cell series Rhino lipo in my GT which is 12.6V at full charge (charged by a $20 computer charger that will charge many types of batteries) that is about 1/4th the size of 8 AAs, much lighter (beyond belief), and has further advantages such as 1 hour charge times that aren't pushing the battery (which can be the case with nimhs), and has almost zero self discharge when sitting on the shelf so that it's ready months or even years later if you ever went that long between charges. These lipos also hold their voltage very high until the very end of discharge, so in fact I find a 750ma pack gives me at least as long of run times as a 1000ma pack, because the faster dropping voltage of the nimh during discharge ends up tripping the low battery alarm faster for me.
However, there are special care instructions for lipos that a user should be aware of. Never puncture, never short, (which is pretty much true for nimhs or nicads too anyway), and a lipo will probably be ruined if drained below 3V per cell (9V total in a 3 cell series pack). While over discharing a lipo isn't dangerous (that's what you do to dispose of them), you should insure the device it is used in will sound a low battery alarm before it drains past 3V per cell. My GT sounds off at about 10.2 to 10.5V or so, so I have no worries about draining past 9V in total.
Incidentally, while nimhs might start out with a lower voltage than store bought non-rechargeables, over the span of discharge there will be a time when the store battery doesn't hold it's voltage as high as the nimh. High capacity nimhs have a much more "flat" discharge line in terms of voltage drop, so that further muddies the waters for people who just refuse to believe that lower voltage will get them the same performance than a higher one.
If you are interested in learning more about chargers, batteries, the charging process, and various other things you probably never wanted to know about rechargeable batteries visit the battery sticky thread in the Sovereign forum. We've linked extensive information to it found in various Findmall threads that goes well beyond specific charging information for the GT or Excal and can be applied to any detector's batteries. Much of this knowledge I've developed over years of building and flying RC electric planes. In the electric plane world if you don't know your batteries well and how to take proper care of them, it could very well cost you a plane. That's why many in RC make it their job to know this stuff, and also why battery technology in RC seems to be a good 10 to 15 years ahead of the curve in detecting circles. It's just not as vital to educate yourself on this stuff in detecting because it's not a life or death situation for the most part.
For me I still seem to see longer run times with them even in low current applications. Shoot for the highest capacity (2500 or north of that) and you'll probably find either virtually no difference in run time that you can tell, or maybe even much longer run times. For instance, in my digital pocket camcorder my 2500ma Energizers give me more run time than good quality Energizer non-rechargeable batteries. I've never actually timed the run time but it's obvious they are giving me more run time when doing video recordings and such.
But, there is one string attached to that. Nimhs or nicads self drain in storage. For that reason run time may be effected if you don't frequently use your detector. If you are considering nimhs, there are now brands that claim low discharge for long storage when sitting on the shelf. Make sure you surf the web and see which passed various tests on this, because some have not lived up to their long term storage claims.
Modern detectors use voltage regulators to provide the circuit board with a steady, constant, non-changing voltage in order to keep things in proper specs. That means it doesn't matter if the voltage is say 10 volts or 12 volts for example, as the circuit board is still only going to see say 8V. The only time it *might* be possible to see a performance flaw is when a battery is so weak that it's voltage is sagging up and down under high power drain moments for split seconds at a time, but in fact high capacity nimhs or nicads have a much more better ability to handle higher amp draws than non-rechargeable batteries.
If you are going through the trouble of building an external battery box and using a custom battery source, I would look into lipo battery technology. All the rage in the RC crowd. MUCH lighter and smaller than the equivalent capacity in a nimh pack. I run a $7 three cell series Rhino lipo in my GT which is 12.6V at full charge (charged by a $20 computer charger that will charge many types of batteries) that is about 1/4th the size of 8 AAs, much lighter (beyond belief), and has further advantages such as 1 hour charge times that aren't pushing the battery (which can be the case with nimhs), and has almost zero self discharge when sitting on the shelf so that it's ready months or even years later if you ever went that long between charges. These lipos also hold their voltage very high until the very end of discharge, so in fact I find a 750ma pack gives me at least as long of run times as a 1000ma pack, because the faster dropping voltage of the nimh during discharge ends up tripping the low battery alarm faster for me.
However, there are special care instructions for lipos that a user should be aware of. Never puncture, never short, (which is pretty much true for nimhs or nicads too anyway), and a lipo will probably be ruined if drained below 3V per cell (9V total in a 3 cell series pack). While over discharing a lipo isn't dangerous (that's what you do to dispose of them), you should insure the device it is used in will sound a low battery alarm before it drains past 3V per cell. My GT sounds off at about 10.2 to 10.5V or so, so I have no worries about draining past 9V in total.
Incidentally, while nimhs might start out with a lower voltage than store bought non-rechargeables, over the span of discharge there will be a time when the store battery doesn't hold it's voltage as high as the nimh. High capacity nimhs have a much more "flat" discharge line in terms of voltage drop, so that further muddies the waters for people who just refuse to believe that lower voltage will get them the same performance than a higher one.
If you are interested in learning more about chargers, batteries, the charging process, and various other things you probably never wanted to know about rechargeable batteries
visit the battery sticky thread in the Sovereign forum. We've linked extensive information to it found in various Findmall threads that goes well beyond specific charging information for the GT or Excal and can be applied to any detector's batteries. Much of this knowledge I've developed over years of building and flying RC electric planes. In the electric plane world if you don't know your batteries well and how to take proper care of them, it could very well cost you a plane. That's why many in RC make it their job to know this stuff, and also why battery technology in RC seems to be a good 10 to 15 years ahead of the curve in detecting circles. It's just not as vital to educate yourself on this stuff in detecting because it's not a life or death situation for the most part.Critterhunter
New member
I posted a thread in the modifications forum, so if anybody has any remarks it should probably be directed there in a forum that is meant for this kind of discussion.
http://www.findmall.com/read.php?22,1748161
I wanted to add though...
Warning: There is still much debate among many on the proper care and feeding of rechargeables, so it's up to you to take proper precautions when charging and using batteries, and you should educate yourself on the net as to just who and what you believe. Regardless of what type of rechargeable you use, always educate yourself as much as possible and charge and store your batteries in a fire proof location. I prefer to store mine in a metal box (lined inside to lesson any chance of a short) as well as to charge them in the middle of a cement floor where I can keep an eye on them. Never assume handling and use of any battery is completely safe.
For instance, many say to drain a lipo completely dead before disposal. Others, however, have reported fires when that happened. I think more than likely they were dead shorting the lipo or draining it at such a fast rate that the battery couldn't handle that fast of a discharge. Still, seek out answers on your own on the web and decide for yourself. I just know the sites I've read recommend draining it completely dead before disposal. Actually, some suggest cutting both battery leads off (ONE at a time! Cutting two wires at once can cause a short!) and throwing it into a bucket of salt water for about a week to insure it's been completely drained of all power.
http://www.findmall.com/read.php?22,1748161
I wanted to add though...
Warning: There is still much debate among many on the proper care and feeding of rechargeables, so it's up to you to take proper precautions when charging and using batteries, and you should educate yourself on the net as to just who and what you believe. Regardless of what type of rechargeable you use, always educate yourself as much as possible and charge and store your batteries in a fire proof location. I prefer to store mine in a metal box (lined inside to lesson any chance of a short) as well as to charge them in the middle of a cement floor where I can keep an eye on them. Never assume handling and use of any battery is completely safe.
For instance, many say to drain a lipo completely dead before disposal. Others, however, have reported fires when that happened. I think more than likely they were dead shorting the lipo or draining it at such a fast rate that the battery couldn't handle that fast of a discharge. Still, seek out answers on your own on the web and decide for yourself. I just know the sites I've read recommend draining it completely dead before disposal. Actually, some suggest cutting both battery leads off (ONE at a time! Cutting two wires at once can cause a short!) and throwing it into a bucket of salt water for about a week to insure it's been completely drained of all power.
Critterhunter
New member
Cupajo said:
I am just now posting a short response/idea for you to consider on that in the mods forum under the thread I started. See there for more...