We get a lot of questions regarding this topic so figured it was time for an article on the topic. A GPS charger comes in three different flavors: AC, DC and hardwired. We will cover all three but first a discussion about the types of adapters.
Most GPS units manufactured over the past five years use a Mini USB ending on the charger (the most popular line which is the Garmin Nuvi has used Mini USB for over five years). Now before you go and purchase a cheap cable made for an older mobile phone, be aware that Mini USB cables are not all made equally. Turns out that the GPS manufacturers use different pin settings versus a phone. If you try to use a cell phone cable, your GPS unit is likely to go into what is called data mode. This mode is triggered when you attach a USB cable to your GPS when loading map updates from your PC. Your GPS will not display a map in data mode but will charge up just fine. Since you are likely looking to use your GPS while powering it with a charger, these cables are unlikely to work well for you.
Be sure to purchase a charger that is made for your brand of GPS. There are plenty of brands of cables out there, and you do not necessarily need to buy one that is made by the manufacturer although you can be sure there will not be a compatibility issue if the cable is made by Garmin, TomTom or Magellan. If you choose to go the non-manufacturer route, be sure to buy one that is made specifically for your brand and one that will push out the proper amperage for your unit. Many of the newer units will require 2 AMPS but many of the older cables only send out 1 AMP. So check before purchasing.
Garmin is somewhat unique in embedding traffic receivers into the charger, so if you have traffic, you need to get a traffic charger. These aren’t cheap and the cables are only made by Garmin. A generic power cable will power your unit, but will not give you traffic.
When charging up your unit at home, select an AC adapter that has the Mini USB ending and pushes out the proper AMPS to your phone. I like to keep my cable on the kitchen counter and keep my unit charged when I bring it inside. If charging your car using your car’s power outlet, you will use a DC adapter. There are a lot of different ones out there. I always recommend a cable length of at least six feet and avoid the coiled cables. Remember that you will need enough length to get from your power outlet to the GPS which is likely to be suctioned to your windshield. I avoid coiled cables because they tend to pull the GPS towards the power source and you never are able to experience the full length of the cable as a result.
We have written a “how to hardwire” article and have it posted here. A hardwire cable is typically used on a motorcycle but you can use it on a car too. The hardwire cable will have a Mini USB on one end and bare wires on the other. They typically are 6 feet in length and have a fuse and power regulator in the middle. We have heard from people that take an AC or DC cable, but the plug off one end, strip the cables and then wire the end to their battery. Please don’t so that. You need a fuse in the middle and something to step the power down. Most DC and AC cables have that ability in the part that you just cut off. Buy a cable that is specifically made as a hardwire.