ka6aru (Jim) Posted January 8, 2005 Share Posted January 8, 2005 Has anyone done any research on rechargeable AA batteries in a GPSr? I was reading a log about someone who couldn’t find a cache until after they changed their batteries that went dead… I know that NiCad’s have lower voltage then standard alkaline batteries… Might that have something to do with me being 70 ft off from a cache sometimes? And I have had people tell me that the coordinates of my caches are a ways off… I have used NiCad’s in my GPSr for a long time… Jim Quote Link to comment
Neo_Geo Posted January 8, 2005 Share Posted January 8, 2005 (edited) Has anyone done any research on rechargeable AA batteries in a GPSr? I use NiMH batteries in mine all the time. A good number of us here do it as well. Might that have something to do with me being 70 ft off from a cache sometimes? Nope. Not a chance! It may have something to do with why you're always changing batteries all the time, but they won't affect accuracy at all. I have had people tell me that the coordinates of my caches are a ways off…...70 ft off from a cache sometimes? Are you using a Magellan by any chance? (yeah - I know I'm pickin' a fight... but it's Friday night!) Edited January 8, 2005 by Neo_Geo Quote Link to comment
peter Posted January 8, 2005 Share Posted January 8, 2005 I agree with NeoGeo. There have been a few reports where people attributed poor performance to low batteries. So I decided to check if there was such an effect in my GPS receivers (III+, 12, eMap - all Garmin). I took a set of brand new alkalines with a measured voltage under load of 1.55 V and a set of nearly exhausted NiMH cells with a voltage of about .95 V. I tried them in the different receivers and switched back and forth between the high and low-voltage cells to check if there was any consistent pattern in either the number of received satellites or the reported position. I wasn't able to see any repeatable change in performance that matched the battery voltage. So at least for my receivers I'm convinced that the performance is independent of battery voltage as long as there's enough to keep them turned on. I used NiCd cells for quite awhile and they worked fine, but only had about a third the capacity per charge of today's NiMH cells. Quote Link to comment
+NightPilot Posted January 8, 2005 Share Posted January 8, 2005 GPS receivers have internal voltage regulating circuitry, and the supplied voltage to the receiver is constant as long as the batteries supply enough voltage to keep the power supply on. Then the unit shuts off, which is why you cannot completely drain batteries in the GPS. Urban legends die hard, though, and weak batteries often get blamed when it's really operator headspace, by blocking the antenna with the body, head, hand, or something else, or else thick, wet foliage. Quote Link to comment
ka6aru (Jim) Posted January 8, 2005 Author Share Posted January 8, 2005 Has anyone done any research on rechargeable AA batteries in a GPSr? I use NiMH batteries in mine all the time. A good number of us here do it as well. Might that have something to do with me being 70 ft off from a cache sometimes? Nope. Not a chance! It may have something to do with why you're always changing batteries all the time, but they won't affect accuracy at all. I have had people tell me that the coordinates of my caches are a ways off…...70 ft off from a cache sometimes? Are you using a Magellan by any chance? (yeah - I know I'm pickin' a fight... but it's Friday night!) It may have something to do with why you're always changing batteries all the time, but they won't affect accuracy at all. MY BAD!!! I do use NiMH... Sorry... Are you using a Magellan by any chance? Nope... A Garmin eTrex... Old Yellow... Quote Link to comment
ka6aru (Jim) Posted January 8, 2005 Author Share Posted January 8, 2005 (edited) I agree with NeoGeo. There have been a few reports where people attributed poor performance to low batteries. So I decided to check if there was such an effect in my GPS receivers (III+, 12, eMap - all Garmin). I took a set of brand new alkalines with a measured voltage under load of 1.55 V and a set of nearly exhausted NiMH cells with a voltage of about .95 V. I tried them in the different receivers and switched back and forth between the high and low-voltage cells to check if there was any consistent pattern in either the number of received satellites or the reported position. I wasn't able to see any repeatable change in performance that matched the battery voltage. So at least for my receivers I'm convinced that the performance is independent of battery voltage as long as there's enough to keep them turned on. I used NiCd cells for quite awhile and they worked fine, but only had about a third the capacity per charge of today's NiMH cells. Cool... That's what I wanted to hear... TNX Edited January 8, 2005 by ka6aru (Jim) Quote Link to comment
ka6aru (Jim) Posted January 8, 2005 Author Share Posted January 8, 2005 GPS receivers have internal voltage regulating circuitry, and the supplied voltage to the receiver is constant as long as the batteries supply enough voltage to keep the power supply on. Then the unit shuts off, which is why you cannot completely drain batteries in the GPS. Urban legends die hard, though, and weak batteries often get blamed when it's really operator headspace, by blocking the antenna with the body, head, hand, or something else, or else thick, wet foliage. Thanks for that info also... Quote Link to comment
alwaysbeezee Posted January 8, 2005 Share Posted January 8, 2005 QUOTE (ka6aru (Jim) @ Jan 7 2005, 04:26 PM) I have had people tell me that the coordinates of my caches are a ways off… ...70 ft off from a cache sometimes? Are you using a Magellan by any chance? What if someone is using a Magellan? Are that bad on batteries? Do you have to reset something every now and then. Thanks Bernie. Quote Link to comment
Neo_Geo Posted January 8, 2005 Share Posted January 8, 2005 What if someone is using a Magellan? Are that bad on batteries? Do you have to reset something every now and then. Thanks Bernie. No, the implication was that Magellans are just bad GPSrs. I was half-kidding of course. Quote Link to comment
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