afriad those runtimes are normal for many RTR models.
The number on the battery (MAH) reflects the runtime.
many RTR's have batteries with 2000-3000mah...which is only good for 10 minutes or so.
I just bought a Arrma raider, and it came with a tiny 1500mah battery.
But a good 5000mah battery can be had for not that much, and should get you 20+ minutes.
Here is a link to a good one:
http://www.hobbypartz.com/98p-5000-7...ble-stick.html
Same goes for the stock charger. Most RTR models provide the most basic charger availible.
The thunder AC6 is a charger which can do most any battery a RC hobbiest will ever have. It can charge my 5000mah lipo packs in 1 hour. A 5000mah nimh battery it could do in less time. The thunder AC6 is availble on the same site as the battery I linked and only costs $50.
There was a time when 10 minute runtimes were the best anywone had. Batteries have come a long way, and its actually good that RTR's can come with a battery that will do 10 minutes. My 1st good electric RC I got 5 minutes tops! And the best batteries of that day could only do 15 minutes!
Please note that if you get a good 5000mah battery...you will need to let the truck cool before running another battery. If you dont give it a few minutes to cool down between packs, it could overheat the motor or ESC.