This is normal if the battery has less than 50% charge in it. Such cut-outs are an indication that you ought to be pedalling more as to avoid overloading the battery. You may want to consider upgrading your battery to one with more Ah to cope with the higher-than-average power demands of your cycling style.
On the other hand, if this issue happens when the battery is fully charged, please send the battery back to us for testing:
1- Copy the link of this page from your browser. Contact us with a brief explanation and include the link of this page with your support request.
2- A technical advisor will be allocated to you and will contact you very soon. They will personally manage your case until it is resolved.
3- If your product is under warranty, our technician will provide you with a unique number and a form which you must include with the items you send back to us. Please note, you must also provide proof of purchase with any items you send back under warranty.