+Bloencustoms Posted February 12, 2003 Share Posted February 12, 2003 I am considering using two 6V lantern batteries in series (12V) and a cigarette lighter socket in a fanny pack to use as an external power supply for my vista. My thinking is that I can just plug the car adapter cord right in and go. I just wanted to see if anyone could think of a reason this might harm the unit, and would it void my warranty? Also, If anyone can give an estimate on how much run time I could expect using the lantern batteries, that would be great. Get off the cellphone and DRIVE! Quote Link to comment
crr003 Posted February 12, 2003 Share Posted February 12, 2003 quote:Originally posted by BloenCustoms:I am considering using two 6V lantern batteries in series (12V) and a cigarette lighter socket in a fanny pack to use as an external power supply for my vista. My thinking is that I can just plug the car adapter cord right in and go. I just wanted to see if anyone could think of a reason this might harm the unit, and would it void my warranty? Also, If anyone can give an estimate on how much run time I could expect using the lantern batteries, that would be great. Get off the cellphone and DRIVE! I don't have a Vista, but in the on-line manual it states (pg 58 or 59) you need to use the 12-3V converter cable - other things will void the warranty. Now as long as you are using the authentic Garmin cable, I don't think whether the 12V comes from a car battery or 2 6V batteries matters. Nil Satis Nisi Optimum Quote Link to comment
Tickridge Photo Posted February 12, 2003 Share Posted February 12, 2003 I'm presently using a 12 seal lead acid battery that I've attached a lighter plug to. The battery is easily recharged and I have lots and lots of use time. Can use it almost non-stop for 3 days without a charge. Bought the battery and charger from radio shack. Used a small camera case with strap to put battery in for ease of carrying. Brian Tickridge Photography Where we "Line'em up and Shoot'em all" Quote Link to comment
Tickridge Photo Posted February 12, 2003 Share Posted February 12, 2003 Sorry that should have said "12 volt" Tickridge Photography Where we "Line'em up and Shoot'em all" Quote Link to comment
+apersson850 Posted February 12, 2003 Share Posted February 12, 2003 I made my own 12 VDC converter for my Vista, by modifying a drive unit for an obsolete analog Ericsson cellphone. Doing it yourself is more fun! Anders [This message was edited by Anders on February 12, 2003 at 07:47 AM.] Quote Link to comment
+Desert_Warrior Posted February 12, 2003 Share Posted February 12, 2003 quote:Originally posted by BloenCustoms:I am considering using two 6V lantern batteries in series (12V) and a cigarette lighter socket in a fanny pack to use as an external power supply for my vista. OK. First a question. Do you really want to carry the weight of TWO batteries when one will do? Mose cheap voltage regulators only need 1 to 2 volts above the regulated output to maintain a regulated output. If the input voltage drops below the needed input, the output voltage also goes lower, but never higher. I cannot believe that Garmin put a lot of work into it. Of course, it could be a simple resistive voltage divider. So try hooking the cable (not GPSr) up to just ONE battery, and use a volt meter to check the output. It should work. In fact, please let us know. quote: Also, If anyone can give an estimate on how much run time I could expect using the lantern batteries, that would be great. Get off the cellphone and DRIVE! See my post at the end of this thread: Battery life. Of course, you would need to know the capacity of your battery, as well as the drain your GPSr uses. I hope this helps. Please. let us know what you learn with the one-battery on the cable. Good luck. Mike. Desert_Warrior (aka KD9KC). El Paso, Texas. Citizens of this land may own guns. Not to threaten their neighbors, but to ensure themselves of liberty and freedom. They are not assault weapons anymore... they are HOMELAND DEFENSE WEAPONS! Quote Link to comment
Cracker. Posted February 12, 2003 Share Posted February 12, 2003 Hmmm....Maybe I'll try this with a NiCD 7.6V RC car battery.....very slim, contained package. Easily recharged, also... I just need to figure out the circuit for a voltage regulator, and I can ditch the cigarette lighter plug, and go with a smaller set-up. Art www.yankeetoys.org www.BudBuilt.com http://www.ttora-ne.mainpage.net/ Quote Link to comment
AKap Posted February 12, 2003 Share Posted February 12, 2003 Vista specification says it likes 3V input? How about two D-cells, some wire, and a little tape to hold the wires to the power pads on the Vista? WATCH THE POLARITY!!! Might void warranty. I tried it on my Garmin eMap and it worked. For a little more of a professional look, buy an eplug from Larry (search yahoo Larry eplug). Quote Link to comment
+Desert_Warrior Posted February 12, 2003 Share Posted February 12, 2003 quote:Originally posted by Cracker7M:Hmmm....Maybe I'll try this with a NiCD 7.6V RC car battery.....very slim, contained package. Easily recharged, also... I just need to figure out the circuit for a voltage regulator, and I can ditch the cigarette lighter plug, and go with a smaller set-up. It doesn't get any easier than this!!! NTE Electronics 3.3 volt regulator. 4.5 VDC to 16 vdc in, 3.3 vdc out. This makes it SO easy! Mike. Desert_Warrior (aka KD9KC). El Paso, Texas. Citizens of this land may own guns. Not to threaten their neighbors, but to ensure themselves of liberty and freedom. They are not assault weapons anymore... they are HOMELAND DEFENSE WEAPONS! [This message was edited by Desert_Warrior on February 12, 2003 at 09:27 AM.] Quote Link to comment
mikeacrossamerica.com Posted February 12, 2003 Share Posted February 12, 2003 leave your guns at home. This is peaceful Geocaching, I choose to weild this weapon for peace. Mf I like nachos. Quote Link to comment
+EScout Posted February 12, 2003 Share Posted February 12, 2003 Get a 12V Gell Cell battery. These are the type used in UPS and alarm system backups. Hook up a cigarette socket and plug in your car adapter. Avantages: 1. Easily charged in your car by directly hooking up to your cigarette socket. 2. Also easily charged at home with a typical 12V DC wall-wart. 3. The battery will power other devices such as cell phones, lanterns, radios, TVs. 4. The battery will recharge cell phone and other batteries that have a car adapter charge cord. Look for the smaller 1.2, 2 or 4 AHr sizes. Quote Link to comment
+Desert_Warrior Posted February 12, 2003 Share Posted February 12, 2003 quote:Originally posted by 20belowZero:leave your guns at home. This is peaceful Geocaching, I choose to weild this weapon for peace Mf I like nachos. I too am peaceful. A more peaceful person you will most likely never meet while geocaching. Most retired combat veterans are, we did enough back then, nothing more to prove. And I did, and still do, carry a weapon for peace. However, times being what they are, being able to defend yourself and / or family is not only a prudent thing. It is also a constitutional right, it is legal, I am license, and those who don't like it just need to get over it. Now... having said that.... If you really like nachos, come on over. We will hop the border to Mexico, and I will show you some really GREAT nachos. Taco Bell doesn't make it here. I make you this offer because I am a peaceful Texan, and Texas is a friendly place. BTW, it is also sunny and warm today, over 60F already, and still coming up. We get our snow on postcards. Mike. Desert_Warrior (aka KD9KC). El Paso, Texas. Citizens of this land may own guns. Not to threaten their neighbors, but to ensure themselves of liberty and freedom. They are not assault weapons anymore... they are HOMELAND DEFENSE WEAPONS! Quote Link to comment
Cracker. Posted February 12, 2003 Share Posted February 12, 2003 quote:Originally posted by Desert_Warrior:It doesn't get any easier than this!!! http://www.nteinc.com/specs/1900to1999/pdf/nte1904.pdf 4.5 VDC to 16 vdc in, 3.3 vdc out. This makes it SO easy! Oooo....All that in one little MOSFET....Hmmm...I'll have to see if that is offered in a SMT DPAK package....Maybe make a little PCB package with a power LED & some other small gizmos... Actually, this one might be a nice choice....I think i read that a typical Magellan sucks 140mA's with the backlight on.. http://www.nteinc.com/specs/1900to1999/pdf/nte1900.pdf Art www.yankeetoys.org www.BudBuilt.com http://www.ttora-ne.mainpage.net/ Quote Link to comment
+Desert_Warrior Posted February 13, 2003 Share Posted February 13, 2003 quote:Originally posted by Cracker7M:Actually, this one might be a nice choice.... Click Here Yes, that one IS a good choice. I selected the other because it is a very simple hookup. I, and probably you, and others I am sure can do the voltage divider or zener on the base. But I wanted to put one up that ANYONE could do. 3 wires is too simple. That's my story and I am sticking to it!!! Mike. Desert_Warrior (aka KD9KC). El Paso, Texas. Citizens of this land may own guns. Not to threaten their neighbors, but to ensure themselves of liberty and freedom. They are not assault weapons anymore... they are HOMELAND DEFENSE WEAPONS! Quote Link to comment
dave and jaime Posted February 13, 2003 Share Posted February 13, 2003 quote:Originally posted by Cracker7M: quote:Originally posted by Desert_Warrior:It doesn't get any easier than this!!! http://www.nteinc.com/specs/1900to1999/pdf/nte1904.pdf 4.5 VDC to 16 vdc in, 3.3 vdc out. This makes it SO easy! Oooo....All that in one little MOSFET....Hmmm...I'll have to see if that is offered in a SMT DPAK package....Maybe make a little PCB package with a power LED & some other small gizmos... Actually, this one might be a nice choice....I think i read that a typical Magellan sucks 140mA's with the backlight on.. http://www.nteinc.com/specs/1900to1999/pdf/nte1900.pdf Art http://www.yankeetoys.org http://www.BudBuilt.com http://www.ttora-ne.mainpage.net/ according the a magellan tech i spoke to the 300's draw 160mAhs without the backlight and 250mAh's with the backlight on. he also said the the merdians were only slightly more power hungry and that a fuse of 500mA would be fine between the gps and a homemade power supply. Quote Link to comment
Dale_Lynn Posted February 13, 2003 Share Posted February 13, 2003 How about considering all those Makita batteries for power tools... 9.6 volt, recharge in 30-45 min... Even has a 12 volt auto recharger.... Now if I can just figure out how to squeese it into the Meridian case.... Dale -------------------------------------------------------- I'm Diagonally Parked, In A Parallel Universe. -------------------------------------------------------- Quote Link to comment
jfitzpat Posted February 13, 2003 Share Posted February 13, 2003 I can't help but think - even one lantern battery is the weight of a heck of a lot of AA's... I must be the only person alive who actually gets 10 or so hours of operation out of my Vista! -jjf Quote Link to comment
Steak N Eggs Posted February 13, 2003 Share Posted February 13, 2003 One 12v batt in the pack works great with my headlight, gps, flashlight, and 2 meter HT for caching at night. A little heavy but works great for me..... "My gps say's it RIGHT HERE". http://www.w6hy.org KF6VFH TOYOTA To Often Yuppies Overprice This Auto Quote Link to comment
+PDOP's Posted February 13, 2003 Share Posted February 13, 2003 If you want to get max life from a 12 VDC battery when using the GPS car adapter cord you might consider disabling the power LED on the adapter. My measurements show it alone ups the power consumption by about 10%. Quote Link to comment
+fizzymagic Posted February 13, 2003 Share Posted February 13, 2003 Everyone who is carrying a 12V battery to run a GPS off of is wasting a lot of power. That's because the GPS typically uses a much lower voltage. When you're running off the cigarette lighter socket in the car, the wasted power is inconsequential, but when you're trying to maximize battery life it's another matter altogether. There are a couple of ways to improve things: first, you can measure the voltage put out by the regulator in the 12VDC adapter cable you have for your GPS. Typically there is a voltage regulator in these things, so all you have to do is get a battery with a slightly higher voltage than the regulator output, and it will work fine with much less power wasted. An alternative solution is to make a custom cable and hook it straight into a battery. To find the minimum voltage needed to run the GPSr, try a variable voltage power supply and note at what voltage the power indicator goes from "battery" to "external." This will typically be somewhat lower than the voltage the regulator puts out. A battery with a voltage between this minimum and the regulator voltage will be quite safe and efficient. For my SporTrak Pro, the crossover occurs at about 3.5 V. Thus, I could externally power the thing with anything higher. A 6V lead-acid gel cell would be pretty good, I'd think. Half the weight of a 12V and the same running time. So: to the original poster: try it with one 6V lantern battery and see if it works. I bet it will. You've just cut your weight in half! Quote Link to comment
Dale_Lynn Posted February 13, 2003 Share Posted February 13, 2003 Why not just pair of "D" cell rechargables in a 2 cell battery holder (radio shack) and wired to external power connection on GPS.... No line regulators needed (if GPS is a 3 volt powered unit). Dale -------------------------------------------------------- I'm Diagonally Parked, In A Parallel Universe. -------------------------------------------------------- Quote Link to comment
+Bloencustoms Posted February 14, 2003 Author Share Posted February 14, 2003 I want to make sure to use the Garmin 12VDC power adapter to get the "juice" to my unit. If for no other reason than the warranty issue. It does make sense that the regulator doesn't require a full 12V input to supply 3v out. Although, a 12V gel cell would have the ability to charge from the car batt. Hmmm. I'll try it out on my yellow etrex first. If all goes well, I'll hook up the Vista. Thanks again for all the input (12V or otherwise). Get off the cellphone and DRIVE! Quote Link to comment
crr003 Posted February 14, 2003 Share Posted February 14, 2003 You're welcome! Nil Satis Nisi Optimum Quote Link to comment
+Bloencustoms Posted February 14, 2003 Author Share Posted February 14, 2003 I know Radio Shack used to sell an adjustable regulator in what I believe was a TO220 case. It only had three pins coming out of it. The beauty of the thing was that it detcted the output voltage externally, so you could us a larger transistor and detect the voltage after the emitter. The little regulator would drive the base of the big transistor. I tried this with a nice big 3055 in a power supply for a CB radio I wanted to use indoors. That made a reg. that was only good for an amp or so handle 6 or 8 amps! Get off the cellphone and DRIVE! Quote Link to comment
+apersson850 Posted February 14, 2003 Share Posted February 14, 2003 That's the standard procedure to beef up a linear voltage regulator. Anders Quote Link to comment
Tazzmann Posted February 14, 2003 Share Posted February 14, 2003 quote:Originally posted by jfitzpat:I can't help but think - even one lantern battery is the weight of a heck of a lot of AA's... I must be the only person alive who actually gets 10 or so hours of operation out of my Vista! -jjf This strikes me as a voice of reason in the darkness. AA's are light, and cheap. Why in the world would anyone want to go through the trouble of doing all this and end up carrying a lot more weight when they're finished? A couple of extra sets of AA's weigh less and are less bulky than most of the alternate solutions I have seen here, as well as being cheaper. Now, if it the answer to "Why are you doing this?" is simply "Because I can", or "To see if I can", or something like that, fine. Experimentation is hella fun. Tazzmann Quote Link to comment
+Bloencustoms Posted February 14, 2003 Author Share Posted February 14, 2003 Well, I suppose the urge to tinker has taken over. Really, I want to be able to go on a looong hike without having to keep recalibrating the compass every battery change, and maintain a lock on the WAAS signals. My GPSr is a toy to be played with. I have a lot of fun with it and while I don't NEED to have hours upon hours of uninterrupted reception, I don't NEED a GPSr at all. So, this little project will give me something to do untill bikini clad vixens come thronging to my door. Get off the cellphone and DRIVE! [This message was edited by BloenCustoms on February 14, 2003 at 12:25 PM.] Quote Link to comment
Cracker. Posted February 14, 2003 Share Posted February 14, 2003 The voltage of the source is almost irrelevant. Of course, you want to make sure you supply just over the devices' resuired voltage input. Anything over that IS wasted, as its regulated down anyway. What IS more important is the current discharge rate of the battery. This is why a 1.5V AA Alkaline can relatively last longer than a NiMH, and more so than a NiCD. They are all 1.5V, but have different current capacities/discharge rates. What you need is to match a battery to the current draw of your GPS. Art www.yankeetoys.org www.BudBuilt.com http://www.ttora-ne.mainpage.net/ Quote Link to comment
+Bloencustoms Posted February 14, 2003 Author Share Posted February 14, 2003 The way I understood it, batteries capacity is expressed in amp hours (or milliamp hours for small batteries). If a device draws one amp, it will discharge a 500 milliamp hour battery in half an hour. Or if the device draws 250 milliamps, it will discharge a 2000 milliamp battery in 8 hours. If I have two 2000mah batteries in series, I get two amps for one hour at 3 volts. Those same batteries in parallel give me two amps for two hours at 1.5 volts. Or alternatively, I could be totally wrong. In any case, most linear regulators use some kind of heat sink because wasted energy is converted to heat. So, ideally I would find a 3v, rechargeable, high capacity battery that weighs less than a lantern battery. The search is on! Get off the cellphone and DRIVE! Quote Link to comment
crr003 Posted February 15, 2003 Share Posted February 15, 2003 I think you're close enough - the discharge time is not a simple ratio. A 1AH battery (spec'd to give 1A for 1Hr) will give more than 2 hours at 0.5A discharge rate - similarly it will give less than 0.5 Hr at 2A. Spec sheets for large batteries have tables to show what discharge time you'll get if you discharge at different rates. Also the temperature will cause a change in the discharge time for the same current - colder gives less time. But I think for the discussion, you are going to be close enough. I'm sure there'll be some more insightful posts coming along. Nil Satis Nisi Optimum Quote Link to comment
Markulous Posted February 15, 2003 Share Posted February 15, 2003 I use an external battery pack of 2 x 3 AA = 3.6v rechargeable NiMHs, the logic being my Magellan SporTrak Pro and Fuji camera use them internally so I need AAs anyway. How & end result: http://web.newsguy.com/markulous/gpscable Mark Quote Link to comment
+PDOP's Posted February 15, 2003 Share Posted February 15, 2003 Nice design and web page Where do you by the battert holders? Also, the Back to Previous link on your photo page is not working. quote:Originally posted by Markulous:I use an external battery pack of 2 x 3 AA = 3.6v rechargeable NiMHs, the logic being my Magellan SporTrak Pro and Fuji camera use them internally so I need AAs anyway. How & end result: http://web.newsguy.com/markulous/gpscable Mark Quote Link to comment
Markulous Posted February 15, 2003 Share Posted February 15, 2003 Got battery compartment in Maplins. Keep meaning to complete website and rewrite the GPS cable section - chucked it on one evening as I had requests to show how I did it! Mark Quote Link to comment
cachethenation Posted February 16, 2003 Share Posted February 16, 2003 quote:Originally posted by Cracker7M:The voltage of the source is almost irrelevant. Of course, you want to make sure you supply just over the devices' resuired voltage input. Anything over that IS wasted, as its regulated down anyway. What IS more important is the current discharge rate of the battery. This is why a 1.5V AA Alkaline can relatively last longer than a NiMH, and more so than a NiCD. They are all 1.5V, but have different current capacities/discharge rates. My NIMH rayovak 1800 mAh batteries from wal-mart give me about twice as long as any alkaline I've used plus I got the one hour charger with a free car adaptor from wal-mart so recharge time is nothing. I usually got about 18-20 hours on a sportrak pro on a single set using the backlight for 2-4 hours of this time. Nathan & Anne Quote Link to comment
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