I have a garmin nuvi 250 and when i plug into the cigarette lighter it says accessory not supported but it is the lead that came with the nuvi when new. It is also stuck in mass storage mode. Will not charge from the lighter adapter in the car but charges ok from lap top. i have had this over 2 years from new

The Garmin will tell you 'Low Battery' if its alternative power source is not available for some reason, so the battery is not being charged. Depending how the Garmin has been programmed, the display on some models will become slightly brighter when a power supply, other than its own batteries, is detected. Check for this.
It is likely that the lead you use to plug into the car is not supplying voltage to your Garmin set. If it plugs into a cigarette holder, check that the cigarette lighter works, or plug in another device to see if there is any electricity to the receptacle. Obviously ensure that the ignition switch is on. If the plug-in bit of the power cable has a light on it, check the light is illuminated. if you have a sensitive tongue, you should be able to put the end of the lead that plugs into the Garmin onto your tongue and you will feel a very slight tingle on your tongue if power is getting to the end of the lead. If not, then there is probably a break in the lead inside the plastic insulation or a problem with the supply plug.
If the plug in lead proves serviceable then you should change the batteries in Garmin as one or more may have failed and will not charge. Check for this by leaving the unit on after unplugging the external supply lead. Depending on the Garmin you have, the unit should remain functioning for at least 30 minutes. The internal batteries will degrade rapidly if the unit has not been use for some time and the batteries were not fully charged before you put it to bed.

Sounds like a bit of a stretch... (nah).

"Lighter" is a GREAT OUTLET...
Has been for decades.

Perhaps it is just time to consider some BATTERY MAINTENANCE... cable and terminal cleaning
or even A REPLACEMENT battery.

I ASSURE you a cigar/cigarette lighter ELEMENT
pulls a lot more power than your Garmin Nuvi 1450LMT.

Get your JEEP battery checked...!!

Carnac the Magnificent

Yes.

There is a battery in the satnav but it's not user replaceable. It can only be replaced by returning it to Garmin. Before sending it away to replace the battery you could check the following;

• Have you the satnav connected to the charger?

• If it's connected to the charger is the cigarette lighter socket working. You can check by plugging in another device to see if it works
• If the cigarette lighter socket is working and the battery of the satnav is not charging it's possible that the fuse in the plug, that goes into the cigarette lighter socket, is blown.

To change the fuse;
Unscrew the ring that's at the end of the plug and the plug comes apart. Be careful not to lose the silver coloured tip. When the plug comes apart you can take out the fuse and get a replacement at any car accessory shop or a shop that sells garmin satnavs.

If you have to return your satnav to garmin you can find their contact details at http://www.garmin.com/garmin/cms/home/support/supportcontact

It's strange if the plug doesn't fit the cigarette lighter socket. They can be a tight fit so if you find it a little big for the socket try putting pressure on it to push it in. If it absolutely won't fit you can buy cigarette lighter plugs in car accessory shops. If you can get one that does fit you can cut the one that's on the lead off and fit the new one.

If you cannot get any plug to fit you can get the lead wired permanently into the car. Any garage would be able to do it for you.

You can get accessories including the car charger from http://www.gpsnow.com/Garmin_nuvi_255_Accessories.htm
However it's likely that if the car charger is not working that the fuse is blown. The fuse is in the plug that goes in the cigarette lighter socket. To get at it unscrew the ring at the end of the plug. Be careful not to lose the small metal tip. When you unscrew the ring the plug comes apart and you'll see the fuse. You can get replacement fuses at any shop that sells garmin satnavs or car electrical accessory shops.

Before changing the fuse make sure your cigarette lighter socket is working by testing it with the cigarettel lighter or some other accessory.

the car cigarette lighter adapter has a fuse at the silver tip of plug, unscrew CAREFULLY its spring loaded, chech fuse and replace if blown.

Check the fuse in the charger plug. The plug that goes into the cigarette lighter socket has a ring up near the end of it. To open it you unscrew the ring. You'll find the fuse inside and it probably needs replacing. Otherwise it may be the cigarette lighter that's not providing power.

maybe it is not charging
does the charging light come on?
both on the unit and on the car power plug.

does your cigarette lighter in the car power other things?

you can charge it with a mini-b usb cable connected to a computer.

The most obvious answer is a possible blown fuse in the cigarette lighter socket or the in the tip of the charger plug. Most charger plug fuses are accessed by unscrewing the metal tip. Check both for good fuses.

If this doesn't solve the problem, make sure the points of contact between the charger, cradle and GPS are all free of dirt and grime. Don't forget to vacuum the cigarette lighter socket - especially if it is used as a lighter, too.