Battery load test is done daily with a delay in hours, the duration of this load test is in secs usually 10, it's not software!
You have too much kit on the system, you have used CCA cable which isn't recommended, it's a SMPS so will get choppy under heavy load.
It's my standard kit and it's not normal behaviour so your speaking to the wrong people.
It also sounds like you have bought the kit second hand or old stock and can't get it to work, there is a possibility you've been past off with old stock with a duff PSU being V6.
Either way there are clearly installation issues. The kit isn't designed for DIY installation and neither is the Smartcom.
You also need to use a proper multimeter not wintex if your diagnosing this stuff.