External battery use for Nuvi 2555

 

I made an external battery pack using 8 2450mah batteries and added an external lighter plug receiver. Any idea how long the GPS will stay on and will it cause any problems? I need to use it on a trip where no out is present.

Update 09/05/2013, Problem solved, I used 8 AA 2450mah rechargeable batteries in a battery holder I had on hand.The GPS lasted approx. 7 hours while using the traffic receiver. Should last longer using a standard cable and lower the display light. I plan on using the gps on a bus trip and there are no 12V outlets. I hope this info might help someone in the future.Everyone have a nice day.