bluetooth vs. CF - battery consumption

DJAmbient · 08-16-05, 08:38 AM

Hi folks, I'm now at the point where I need to select the gps hardware. I am primarily going to be using this in the field and not for street directions.

My question is which would be more efficient from a battery perspective. Would an Axim x50v with a CF GPS use it's battery faster than having bluetooth on and communicating with a standalone bt gps?

I suspect the later is going to be less of a drain but then again the bt gps will need it's own power source and that's an issue. Might I be better off with just another spare battery or two for the Axim?

Is there any major difference in the drain on an Axim in units like the GlobalSat Compact Flash GPS at just $89 vs.. some of the higher end units?
thanks
DanD

JakeRich · 08-16-05, 09:37 AM

DanD, the specs normally say what the power drain of the CF card is. For the GlobalSat receiver at

http://www.globalsat.com.tw/english/...id=21&p_id=104

the power draw is about 90 mA. That is about 25% of the draw of the Axim itself, so your battery life will be reduced about 20-25% with that card in and operating over normal, non-BT operations. BT operations take, I am told, about 50 mA (No science in that number, just seem to recall reading it somewhere.) If that is correct, the net difference will be on the order of 10-12% shorter battery life with CF than BT. But most of us use a powered cradle to provide both support, power and audio amplification of some sort so the power consumption of the card vs BT is not really an issue in that case. The battery life of the X50v really demands an external power supply for any significant GPS work at all.

08-16-05, 10:04 AM

According to Haicom's website the 305N CF GPS pulls only 32mA. And you can get a bluetooth slipper for it if you do ever want to go bluetooth.

The numerix chipset was made for low power, although it is not as sensitive as a SiRF star III

Also the 2200 battery would sure help.

http://www.haicom.com.tw/hi_305n.shtml

srf506 · 08-16-05, 03:30 PM

Yeah, but like Jake said, most of the time we're using them hooked into powered-mounts in vehicles. Most of the mounts won't accomodate the extended battery. But since we're powered anyway who cares? If you're geosynching or something where you're dismounted you'll definitely need to carry a couple of extended batteries.

cherrylee14 · 08-17-05, 06:40 AM

I think CF vs BT gps all comes down to a personal preference. Here's why I chose BT GPS.
(1)Appearance: I don't like a CF card sticks out of x50v. Especially with CF GPS' antenna, that'd really bother me while driving. Some aruges that wiring BT receiver to a power source is ugly. But I rarely charge while driving as I describe below.
(2)Battery: For one simple charge, my BT gps recevier last for 16-20 hrs. I can simply recharge it at home overnight, or I can charge it while navigating as well. I see x50v is very power-hungry and in case of hiking for later use, I don't want my gps uses x50v battery.

DJAmbient · 08-17-05, 07:29 AM

Thanks for the opinions. While driving and external power connections are not the issue in this case, getting the info on battery consumption has helped a lot.
DanD

dlweston · 08-17-05, 07:32 AM

Originally Posted by srf506

Yeah, but like Jake said, most of the time we're using them hooked into powered-mounts in vehicles. Most of the mounts won't accomodate the extended battery. But since we're powered anyway who cares? If you're geosynching or something where you're dismounted you'll definitely need to carry a couple of extended batteries.

You do not need a couple of extended batteries. Just get a battery extender. Here is a thread on it:

http://www.aximsite.com/boards/showt...ttery+extender

I personally use this battery extender:

http://store.yahoo.com/semsons-inc/pdabatexpocp.html

It say it is not for the X50v, but if you ONLY use 4 x AA NiMh rechargable batteries, it works fine for me.

DJAmbient · 08-18-05, 08:45 AM

Any idea why they say it is not suitable for the x50v?

dlweston · 08-18-05, 11:35 PM

It is actually the X50, not just the v model. They are picky about the input voltage they will use. They offically use 5.4 VDC for charging. If the voltage gets above around 5.8 VDC, some people have reported they quite charging. Down around 5.0 VDC, they also quite charging. With 4 1.5 VDC alkaline batteries you will have 6VDC or actually even more. If you use 4 1.2 VDC NiMh rechargable batteries that is suppose to be 4.8 VDC, but my extender puts out 5.2 VDC. I also have a 5 VDC car charger that came with my bluetooth GPS unit but it measures a little over 5.1 VDC. I used it to power my X50v when in the car until I got my Seidio powered mount.