Using "off-brand" chargers

 

Well, based on favorable feedback we got here, we bought the Nuvi 3700 with lifetime maps. Is this unit slick or what? It's thinner than my iPhone and the screen resolution is far and away the best I have ever seen on a GPS unit.

The car charger it comes with outputs 5V/2A. It comes with no other charger.

My iPhone charger outputs 5V/1A, and I am fairly certain that it will safely charge my Nuvi, albeit slowly. It charged my old Nuvi 650 for a number of years, and that unit is still ticking away just fine.

My iPad charger outputs 5.1V/2.1A. I believe this would charge the Nuvi and at a faster rate.

But I have a question: is the fact that the iPad charger is .1V/.1A over the output of the Nuvi car charger something about which I should be concerned?

Am I safe/it is wise to charge the 3700 with then iPhone or the iPad charger or am I best advised to buy a Garmin, unit-specific charger.

Thanks in advance for any feedback or suggestions

--
Nuvi 3790T w. Lifetime Maps/Macintosh OS Lion/iPhone 4/iPad 1

~

You can use an iPad charger fine on an iPhone... so charging your 3700 with the iPad charger will be no problem.

--
*Keith* MacBook Pro *wifi iPad(2012) w/BadElf GPS & iPhone6 + Navigon*

Chargers

The difference between 5v and 5.1 volts is one of no consequence. In reality the two chargers will be rated the same. The difference in current is another matter. The current rating of a charger is the maximum current it can safely deliver. But that doesn't mean that it will ALWAYS be delivering that current. The supply determines the voltage delivered to the load (your GPS) while the load determines how much current it needs from the supply.

See if you can find the specs on your GPS, they should list the current draw. If the current requirement is under the iPhone charger's 1 amp then you will be okay. If the GPS draws more than 1 amp then I would find some other way to charge it.

Better safe

For only $15 you can buy a charger. Look at Amazon and see what they have. I would think it would be better to use what is made for it just to be safe, but I know nothing about electricity other than pluging it in!! grin

--
Mary, Nuvi 2450, Garmin Viago, Honda Navigation, Nuvi 750 (gave to son)

Clutter!

mgarledge wrote:

For only $15 you can buy a charger. Look at Amazon and see what they have. I would think it would be better to use what is made for it just to be safe, but I know nothing about electricity other than pluging it in!! grin

You may be correct, but if it were me I'd chance it and use the same cable just to reduce the clutter in my car.

Chargers

scott_dog wrote:
mgarledge wrote:

For only $15 you can buy a charger. Look at Amazon and see what they have. I would think it would be better to use what is made for it just to be safe, but I know nothing about electricity other than pluging it in!! grin

You may be correct, but if it were me I'd chance it and use the same cable just to reduce the clutter in my car.

^
DITTO. What he said

All USB are basically the same

All USB chargers are basically the same, they all put out 5V plus some minor deviation, with at lease 500mA.

The only difference is the charging time will be different. On the thirsty device like GPS, it will take much longer than the charger that came with the unit.

I use only one charger for all my electronic gadgets that accept USB (and mini/micro), and sent the rest to the storage pile. So far, I have not had any problem what so ever.

Using "Off-Brand" Chargers

Once again, I really appreciate the feedback on this topic.

Here's the feedback I got when I posted the same queation on a Mac List to which I subscribe:

*****
The GPS charger having a rating of 5V/2A indicates that the GPS will draw no more than 2A from a 5V supply. It may draw far less, but as a 5V/1A charger is cheaper than a 5V/2A unit it won't be much less.

What will happen when you charge the GPS from a 5V/1A charger will depend on the design of the charging circuit within the GPS and the over-current protection of the charger. If it works * and nothing gets hot * then they will probably continue to work fine together.

Similarly with the other combination. If it works and * nothing * get hot you're probably ok.

The problem is that there are possible designs of both charger adaptor and GPS charging circuit that together could cause one or the other to get hot and/or blow -either after a while or instantly.
*****

Now what worries me is the *and nothing gets hot* qualifier. One comments that comes up over and over again on the Amazon.com ratings of this unit is the issue of overheating. My wife has used this unit once (it was not attached to the car charger when she did) and she noticed no heat issues at all.

I charged it once with the iPhone 5V/1A charger, and the unit seemed warm, not hot, to me.

Given that I have been charging my old Nuvi 650 with an iPhone charger for years, trouble free, I think I am going to use the iPhone charger.

Again, most appreciative of folks taking the time to weigh in on this question.

--
Nuvi 3790T w. Lifetime Maps/Macintosh OS Lion/iPhone 4/iPad 1

Give It A Shot...

I've worked in electronics all my life, primarily in the installation, maintenance and repair of broadcast systems, and I can't imagine you'll have a problem. Most modern devices are smart enough to "know" when they need more current than the supply is capable of providing and they'll let you know, if that's the case, with a message of some sort telling you that the charger is incompatible. Even when they don't, the result is highly unlikely to be damaging to your device. Your hopes and dreams, maybe, but rarely your device.

Give it a shot! Chances are it will work just fine!

You won't notice the difference

**My iPad charger outputs 5.1V/2.1A. I believe this would charge the Nuvi and at a faster rate.**
This will be fine. It is a negligable amount of voltage/amps difference.

And, yes the 5v/1amp will charge slower than the 5v/2amp. But all devices will know when to stop charging. It will get a little warmer during charge also (5v/2amp).

--
Nuvi 2460LMT.

Switching power supply

A switching power supply keeps the voltage exactly to the specs regardless of the amperage load.

However, the older transformer kinds produce the 5 volts at a particular amperage load. Hook this up to a larger or smaller amperage load and the voltage might indeed be different.

Howard

Charger

Here are things to consider:

1- Voltage. You need the right voltage. This is very important. Yes, 5.1V is ok if the optimal voltage is 5.0.

2- Amperage (current). You need to be above the minimum current required by your GPS. If your GPS needs 0.5 Amp, you can buy any charger equal or above 0.5 Amp.

Note: a 2.5 Amp charger will NOT charge faster than a 0.5 Amp charger. It just means it can provide more current.

3- Polarity. This is not a problem with any USB-type adapter, but if you have a device with a pin-type plug, the positive and negative terminals are sometimes swapped from one device to another.

A note about switching power supply and linear power supply (from posts above)

If you look closely at their specifications, both type of power supplies will have a different voltage depending on the load (the amount of current) you put on them. Although switching power supplies will vary less, the variation in linear power supplies is generally low enough and it does not affect the circuit to which it is connected.

For example, a 5V linear supply may be at 5.2 volts when no load is connected to it and 5.0 volts at the optimal load. It may also be at 4.9 volts if the load current goes above the optimal specification. In all cases, the device connected to it should work properly.

About "things getting hot":

If the GPS uses a linear voltage regulator (which is not the case), the higher the input voltage the higher will be the dissipated power to bring it to the right voltage. You generally do not want to do that.

Most of the newer devices (which include GPS), use switching power supplies. They will convert higher voltage to the lower voltage needed by the device. For example, the 5V from a charger will be lowered to a 3.3V. The power dissipated will be very very low since most of these new components will have an efficiency of 90% or more (nowadays at least 93%). You could also use a higher voltage (like 6V), but if you go too high (like 12V), the efficiency can be lowered (75%) which may heat things up a bit. If you also go above the input voltage specification of the GPS switching supply, you may break the part. Some 5V to 3.3V switching supply may accept up to 6V and will be damaged if you go above 7V.

A slight correction

Turbocc and HowardZ, there 2 types of transformer power supplies, regulated and non-regulated. The cheaper type that used to be supplied with portable electronics were usually non-regulated. They have a transformer, rectifier and filter capacitor. Their voltage regulation was typically very poor but their current rating could be several amps.

The regulated type are as above with the addition of a 3 terminal solid state voltage regulator. They are typically rated at 1 amp or less but have very good voltage regulation.

Switching supplies are more common today because they are MUCH cheaper to build and have better specs. but they do produce RF hash which can cause problems for AM radios if not properly filtered.