[DRW1000]

I had a similar problem where the vehicle would be completely dead some times and great other times. It always accepted a boost and never acted as if there was a bad battery loading the system down during boosting.

Turned out to be the terminal in the battery. The female terminal of the battery was broken/cracked. I tugged on the negative side of the battery and the cable and the female insert of the battery fell right off. I ended up replacing the battery and have had no troubles since.