Engine system fault on 2009 range rover sport. Loss of acceleration. Don't start

First you need to test the battery and get that squared away. If you can get the truck over to a local parts store then have them load test the battery and alternator. If you need a new battery, start there. You will need a good scanner to figure out the hesitation issue. You can scan for codes and watch actual values from various engine computers. This part requires some knowledge and experience so if you prefer to use a shop, then use this link to find a good shop near you. https://repairpal.com/repair-shops Alex