On Wed, Jun 2, 2010 at 7:18 AM, Dave Mcneely <mcneely4@cox.net> wrote:

> ---- John Rodgers <inua@CHARTER.NET> wrote:
> > What capacity in Amps do  you think would be appropriate for jump
> > starting either the Vanagon or another vehicle?
>
> More than one of those cheap portable hot shot devices makes available.
>

If you have a really dead starting battery the portable battery packs
probably aren't going to work. Most of them are a 17ah battery inside.  They
will work with a battery that is just down to the point where it won't turn
over the engine.  But big or high compression engines are going to be hard
to start with the jumper packs.  And the connections become critical.  If
the clamps on the jumper cables are corroded and you can't get a good
connection no joy.  Apparently the jumper packs the tow truck drivers carry
are beefier because I've seen them start engines with flat dead batteries.
The advantage of hard wired high amperage connectors (like the big Powerpole
connectors mentioned earlier) is that you get a good connection on that
end.  IIRC a starter is going to try to draw 75-85 amps so wimpy jumper
cables are going to heat up fast and also use a lot of amps just pushing
through wires that are to small.