Sorry could you advise me how you would test them please. Thanks
Power consumption varies with speed to the cube, hence very sensitive to headwinds. The next factor is motor type. Hub motors tend to give you more miles - about 30miles-33 miles for a 36V10AH battery, crank drives about 10%-20% less because most people with CD motors tend to ride 20% faster, direct drive motors are worst for consumption because of very low motor efficiency at low speed, frequent start/stop at traffic lights in town can easily half your miles. The next factor is the maximum continuous output of the battery. If this factor is low, your battery will sag heavily when climbing hills, reducing range due to Peukert effect.
Tell us what motor/controller you have, we can advise what is reasonable to expect.
How to test:
Your battery is at least functional, so the main reason for testing is to find out if the capacity is as advertised and if the cells are well balanced. The simplest method that you can do at home is to get yourself an energy meter, something like this:
http://www.ebay.co.uk/itm/Status-Plug-In-Energy-Meter-kWh-Electricity-Monitor-Consumption-Usage-Analyzer-/141833338442
Charge your battery to full, reset your trip meter.
Ride until the battery is pretty flat.
Let's say you ride 15 miles.
Plug your charger to the energy meter and plug the energy meter to the wall socket.
Charge up the battery to full.
Check the amount of electricity used.
On a good bike, one would expect to see 5AH used. The power consumption shown onyour meter should be about 200WH.
Now measure the voltage of your battery.
When it's 100% full, it should be 41.5V, when it's very flat, 31.5V, so you should expect to see 36V.
You get the idea.