do lithium batteries really make a differnece in GPS units?

Lithium batteries have three to four times the energy density compared to an alkaline battery. They cost more, but they last longer. Also, they tend to be much lighter in weight.

–B.G.–

Hi, Dan.

I don't often use a GPS on backpacking trips, but I do use a mapping GPS unit for kayak expeditions. For kayak expeditions I leave my GPS on a good bit of the time, and I've found that lithium batteries do last quite a bit longer.

Lithiums last wildly longer. I hiked the PCT and CDT with GPSs on all day long. They're the way to go.

I think it will depends on the power requirements of the GPS unit and the power curve of the batteries you're comparing. I don't remember it making much of a difference in my eTrex Vista.

Lithium only in my foretrex 101.

yes they last a lot longer, the more in winter.

Alkalines are a lousy option because of how they respond to high current loads–voltage output drops quickly and progressively with time. Even though good alkalines and lithium cells have the same capacity (in mAH) at room temperature, alkalines drop below minimum operating voltage well before they're exhausted while lithiums hold their voltage until nearly exhausted.

I only use NiMH or lithium cells in my GPSs. Fresh NiMH cells will give me two to three trail days; I only use lithium on longer trips (because I'm cheap).

Note that most, if not all handheld GPSs have a battery setting to enable the power meter to give an accurate reading.

Cheers,

Rick

Yes

Cheers

Because you Didn't Ask…

I assume you asking about Lithium and not Lithium Ion?

Cause the first is not rechargable but does put out about 1.7 +/- volts, and is probably compatible with a typical AAAx2 or AAx2 voltage requirement.

The Lithium Ion is rechargable, but puts out 4.0 +/- volts, and will probably cook your GPS.

BTW, A Nickel Metal Hydride battery is the right voltage, and is rechargable.

Thanks for all the great responses everyone!

Greg, I am not aware of any handheld GPS receiver that uses a lithium ion rechargeable battery. Generally, when somebody refers to a lithium battery, they mean a lithium primary battery, and when they refer to a lithium ion battery, they mean a lithium ion rechargeable. Yes, lithium ion rechargeables tend to have a higher voltage, and that makes them incompatible for more normal devices.

One advantage of a lithium primary battery is that it can output huge amounts of instantaneous current. So, that makes them good for things like an emergency radio transmitter. They have a very long shelf life, maybe ten years, so that makes them good for some emergency device that is packaged and stored for a long time before use. They are lighter in weight, which makes them appealing to people here.

If I were using a GPS receiver for an hour or two per day, every day, and if I had a powered up charger for batteries, then the Nickel Metal Hydride rechargeables work good and are very economical.

It's all a matter of compromises.

–B.G.–

my gps wont work on any battery that is not ~1.5V. NiMH or NiCd put out 1.4+ V at first when overcharged, quickly drops down to 1.25 V or so under load, then hold that until about 90% discharged. The low voltage cutoff will turn my gps off thinking the NiMH or NiCd batteries are dead somewhere around 1.4V, only about 20 min after putting fresh ones in.

Lithium will work with no problem, and is lighter to boot.

I put a voltmeter on a new lithium AA battery, and I was expecting to see a no load reading of 1.6 or 1.7 volts. To my amazement, it read 1.8 volts. Under load, that will drop down a bit. It still seems hot.

NiMH and NiCd batteries normally last pretty good when they are new and properly charged. However, if they get funky over time, they still show a fairly normal 1.25 V or so under load, but the load current can be critical and they crap out soon.

Try some new ones that are properly charged and see if they don't do much better.

–B.G.–