All Batteries are NOT the Same!

Okay, almost every GPSr today uses AA batteries. However, just because two batteries are AA size doesn’t mean they provide the same amount of energy over time. Essentially, yes, all AA batteries will start out producing about 1.2 Volts, +/- .1 Volt. However, due to the chemical composition of the batteries they will have different discharge rates, or ‘lives’. To get the most out of your batteries (especially rechargeables), you’ll need to ‘team up’ your batteries. Here’s an analogy:  you are responsible for assembling a cross country train that will be hauling dozens and dozens of cars. Further, you’ll need two locomotives to haul these cars and you have different kinds available to you. If you’re wise, you’ll pick two of the same kind, and here’s why.

If you select two of the most modern diesel locomotives, they will produce the same horsepower, travel at the same speeds, and have (basically) the same ranges. Each locomotive will work in concert with the other.

Do you see a problem here? 

While the venerable puffer-belly had its day in the sun, it’s no longer a match for its successor. The steam engine has neither the strength, speed, nor the range of the diesel. As a result, the diesel will end up pulling all of the cars behind it AND must push the locomotive in front of it. As the steam locomotive finally loses steam (pun intended), it becomes nothing more than dead weight for the diesel. Not good.

We do the same anytime we put two different kinds of batteries in our GPS receiver. Firstly, batteries must be the same type (NiMH, NiCad, Li Ion, Alkaline, rechargeable Alkaline, etc.)  Nextly, the batteries should have the same CAPACITY. This is measured in mAh (milliamp hours). Now, I’m always on the look out for great deals in rechargeable NiMH batteries. As a result, I have a bunch of batteries with different capacities. Here’s a photo showing some of the different kinds I have:

If you look closely, you’ll see that one set of batteries have a 2000 mAh capacity, another with 2500, and the last with an advertised capacity of 2650 mAh. I stress the word ‘advertised’ as I’ve heard there really isn’t anything with greater capapcity than 2500 mAh. But…

Equally important to using the same kind of batteries together is CHARGING them together. Never charge different kinds of rechargeable batteries together, nor batteries with different capacities. While not necessarily dangerous in the case of AA rechargeable batteries, it can shorten their lives.