New and confused! Help with Mad Monkey PLEASE

[GE90]

Hi All

Really would appreciate some help. I have a new Mad Monkey, brushless, and am becoming more confused by the day! Can anyone help with the following?

1) After only a short time (a few mins), the car goes into a slow mode, and the blue light on the std Ansmann ESC flashes. If I turn car off and on, all seems fine again for a short while, but soon repeats itself. I checked the battery (LiPo 2S 20C 4000), and it read 7.5 v, after only a few minutes! is this right, does the blue flashing mean low battery? My also new HPI battery duff?

2) I fitted uprated Aluminium shocks, but one rear driveshaft seems to pop out of the diff occasionally. Checked the length of the shocks, and the std ones measure 95mm ctr to ctr, but the uprated ones are 5mm longer... Any ideas, as this 5mm contributes to the wrong driveshaft angle.

3) Can anyone recommend another LiPo that will fit? I think it need to be rounded, with deans connector. Looking for about 4000mAh.

Sorry for all of the questions, but a search has just confused me more!

Thanks