With all the gear we have that use batteries for power, I'm wondering if anyone has seen results of tests that show the miliamp/hours of power available from different battery options, for example AA alkaline, AA Lithium, and maybe the so-called Ultra Duracells? It will probably vary with different rates of drain. Some results for rechargeable batteries might be interesting, also. I've noticed that the Garmin GPS 12 really eats batteries-almost too much to use it for constant operation. I usually just turn it on for a location/distance or speed check while in currents. It also has the annoying habit of switching on in a waterproof case unless you tape something into place to shield the on-off switch from accidental contact. Regards, Jay *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
On Wed, 14 Mar 2001 <jaymtb_at_amigo.net> wrote: > With all the gear we have that use batteries for power, I'm wondering if > anyone has seen results of tests that show the miliamp/hours of power > available from different battery options....It will probably vary > with different rates of drain. Yes it does vary with rate of drain. Many people do not seem to understand this. In particular, alkaline batteries perform quite poorly in comparison with rechargables in high-drain devices. This becomes immediately obvious to anyone who has done real-life comparisons between alkalines and high-capacity rechargables in devices such as camera strobes. In such devices, good rechargeables last much longer than alkalines even though they have a lower rated capacity. As Garmin data shows, even VHF radios can benefit from high-capacity rechargables if the use cycle involves much transmitting (which places a high drain on the batteries). Note the following test results from Garmin for their VHF725 radio, which can use both an alkaline tray and a high-capacity NiMH rechargeable: Tested using 5% TX (high 5W), 5% RX, 90% standby duty cycle Alkaline(6 AA): 5 hours NiMH: 13 hours (source: http://www.garmin.com/products/vhf725/spec.html) You can get dramatically improved battery life if you transmit on low, and if you do not leave the radio on continuously. Using a lower transmit power also decreases the performance advantage that high-capacity rechargeables have over alkalines. Again, note the following test data, this time using the Garmin VHF720's 3W transmit power: Tested using 5% TX (****high, 3W****), 5% RX, 90% standby Alkaline(6 AA): 19 hours NiMH: 24 hours (source: http://www.garmin.com/products/vhf720/spec.html) If you only transmit on low power, the numbers increase even more, and alkaline batteries will actually do a bit better than high-capacity rechargeables (although the difference is small). If you do not leave the radio on and transmit primarily on low, you can easily get a week or two out of a good rechargeable battery or a set of alkalines. I have quit carrying my alkaline battery packs, and now carry spare rechargeables. Two 1200mAh rechargables easily last for two weeks (in fact I usually only need one), but I carry three just to be on the safe side. I only leave the radio on when my group is split up, or when I am using it to get weather forecasts or radio checks. I cannot stand listening to radio chatter when I am paddling. I also do not like it when other paddlers leave their radio on, as this creates noise pollution that can travel surprisingly long distances over the water. Jay also wrote: > I've noticed that the Garmin GPS 12 really eats batteries-almost too > much to use it for constant operation. You obviously have a very old one. The G12's newer hardware platforms (available for the past few years) with the most recent software update (available for the last year or so) provides up to 36 hours of battery life on battery-saver mode (again, this requires a software update), or 24 hours in standard mode. I regularly get 30 hours from el-cheapo alkalines. A lot of the older G12s with the 10-12 hour battery life were sold by retailers long after the newer hardware platform came out. A lot of customers were "ripped off", in the sense that they have paid far more for their GPS (including battery costs) than was necessary. If you want to keep up on such things and avoid getting ripped off buying obsolete equipment, read the sci.geo.satellite-nav newsgroup. Dan Hagen *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
This archive was generated by hypermail 2.4.0 : Thu Aug 21 2025 - 16:33:21 PDT