Theorectically if it is 10A @ 12V then it should easily cover 2*5A chargers @ say 7.2 - 9.1V.
However, i've got a current meter on my PSU and the difference in power draw (and hence efficiency) between two of my chargers is MASSIVE. My Pulsar is very efficient and draws about 3.8A @ 13.8V(what power suppley gives out), but the Novak is something like 5.4A @13.8V, which means it's something like 50% efficient
Which explains why the fan is always on when charging.
Conclusion, first try it!
Secondly, buy one of these, amazing value for money.
http://www.modelsport.co.uk/index.ph...n&ItemID=23410