Hello Transit Electrician … A question to you. My Ford Transit Built 92, 59 KW Diesel was a so-called catastrophic vehicle, so with a lot of senseless snap, for that he also needed the 2 battery. All the snap is removed, and the cables are removed from the battery … Would it bring anything if I connected the fully charged second battery to the so-called main battery so that the car has more power at the start ? if yes, how strong would the you need And am I right if I assume to connect the second battery with a cable from minus the second battery to minus the main battery and another cable from plus the second to plus the first battery ??? The transit only starts very powerless, although the starter, the Lima and the battery is new and has early over 12 volts voltage. If I leave it standing for 3 days, it does not start at all, although the battery has over 12 volts. Air filter is new, oil is also new …don’t know any more and would like to save me the passage to the workshop, because there is certainly every cable examined and thus costs a lot of coal and in the end they find nothing. I thank you for an answer