Mobile phone as sat nav (gps on) is useless!!!

Ive been using my phone (samsung S2) as a bike sat nav when needed. My bike has a cig lighter socket fitted so I can use a car charger to charge the phone whilst riding.

Unfortunately every phone Ive tried uses more power when the gps is on compared to the amount being fed by the charger so in fact it's discharging at a slower rate.

So, I tried a higher amp charger but the phone will only suck a limited amount regardless of what you are feeding into it. This is guess is to preserve the battery recharge life.

 

worth checking the specs of the adapter as some, whilst rated at a higher amperage, do not short the data pins on the usb connector therefore the phone doesn't know that its connected to a "fast" charge charger, and assumes it connected to a standard usb port which supplies max 500ma . Also cant comment on the s2 but ive used mine (s3) absolutely fine as a gps on the bike without discharge powered off a 12v usb adapter.

 

further investigation shoes that the s2 can draw a max 650ma, looks like a hard coded limit to keep the internal temps down. so the higher amperage adapters arn't going to help much anyway. personally when im running the phone as a gps, I make sure im running on power save mode anyway, which drops the background process's down, and make sure the wireless etc is off aswell.. this should help with power consumption.

 

As Deano said turn all off

 

Thanks! I have a 1amp output on the charger and have shorted the data pins already so it charges at a faster rate. The only way I can halt the discharge is by running it in aeroplane mode after my route has been selected on Google maps. Luckily is stores the route info in memory so no further data is required unless you change your route. Thanks for the info, it was helpful.

 

Hmm get a cheap dedicated sat nav prog for phone that has the map database and not use google maps that is connecting to internet

 

I get this with my iphone when I use navfree. I have a tomtom that was given to me by work that I don't use so I may dig that out and see if it fits in to my phone holder on the bike.

 

Ive tried Navfree before and although its not bad for a free off line gps, we didnt really click.