Powerfull, sorry to hear that you're not happy with your Cyclamatic MTB, as it really is quite a good beginner's bike.
Firstly, SportsHQ are normally pretty good at communication. After the initial contact with them using thier website contact form, use the reply facility in your email client.
Make sure that you always use the same reference number on further correspondences with them.
Here are my experiences with the bike, so that you may compare and decide if you have a dodgy battery.
Remember not to expect a full on throttle ride everywhere ability with this bike. It has only been designed to assist pedaling.
Battery charge to green light from empty - 6 hours.
Around the 4 hour mark at half discharge.
Remember that the throttle LED guage is useless at predicting the juice left in the battery. Although it can be good at showing you how hard you are working the motor and ultimately the battery.
Once you have conditioned the battery fuel guage, to check it properly you need to have stopped and not used the motor for a minute or two.
Checking it straight after a motor assist will give a false reading.
Also, do not rely heavily on an accurate indication with the guage. As it only has 3 LED's, it's pretty poor at best for giving you info on the state of your battery charge. Full/half and empty, that's it
Saying that, i start heading home on the guage half way mark. Wouldn't want to pedal this unassisted.
Will take off from standstill with throttle only to 15MPH on flat, but takes a long time to reach terminal velocity
Will take off from standstill on slight inclines but will struggle to reach a good speed. Not good for battery
The pedelec sensor is actually pretty good at detecting how much assistance you need.
To get the max assistance on hills, your legs need to be turning the crank pretty fast to get full assistance. I think you have already found that the lowest gear doesn't turn the crank fast enough on a hill, hence less power assistance and the feeling that it's not working.
In this case use the throttle as it maxes the assistance. Not good for battery with prolonged use, but i found that the motor runs fairly cool under these conditions.
In top gear, once around 17MPH is reached, pedaling faster tends to induce a feeling of resistance. This might lead a rider to think that the system isn't working properly.
It is, just the motor creating drag and assistance peaking off.
With no motor assistance this bike does not pedal and feel like a normal non electric MTB.
Plenty of drag from the motor. Sometimes, if you don't keep the pedals turning smoothly, motor assistance cuts for a moment and you get a feeling that something is wrong. Perfectly normal.
Although almost impossible to indicate a working mileage in your case, i get around 15 miles until i suspect there's very little juice left.
This is with the following mixture of road riding:
70% flat (half of this using full throttle assist)
20% moderate hills (pedelec assist)
10% severe hills (pedelec assist)
Hope this helps