I've received my invoice and am going Tues to do a "recovery". I was able to go and inspect "A92" last week and both batteries are dead. I have someone who is going with me who has 2 of those jumpacks like you carry in a trunk. Should we hook one to each battery? Since the batteries are in series won't we be hooking a 12v pack into a 24v system, damaging it? Should we hook the + from one pack to the - of the other, putting them in series and jump that way? Should I just go get two new automotive batteries, which will be replacing the ones in the truck now, and use them? I did a search and got a lot of differing viewpoints but nothing definative. Any help appreciated.