New Battery for Model NNB-B15?

I can see some great help here before. I have the NSpire and the battery is a A41-B35 with rating 3000mah, 45w but I cannot find the correct replacement part? Can anyone provide some wisdom, the choice is wide and often cheap imitations with little power.
I could easily be persuaded to buy a more powerful battery if one existed so any help here too would be amazing?

Hi there,

Best option will be to speak with some of our sales people. You can contact them through a livechat service found here or you can phone them on 02392 322500.

If they don’t know the answer straight away they will be able to speak with our product people and find the right battery for you.