Dumb Question Jump Start

Providing the second battery has full charge, yes a jumper lead positive to positive and it should turn over and start.

Then get the whole system checked out and ask them to explain how it all works so you have a better understanding of it all.

Sounds like the two batteries are connected together in parallel.
If so and they are not isolated by a "smart" controller, then both batteries are probably flat.

To stop reoccurance, have the "autolec" recommend a smarter solution.

(Quote)It seems they both run the sytem. My question until I get back to see an autolec, can I jump start one battery to the other with jumper cable? What do you think of possible damage? (end quote)

With the second battery, or the one you believe is NOT the starting battery, can you follow the lead from the (+) terminal to where it connects to...??

If it goes direct to the other battery it is wired in parallel, and if the vehicle don’t start then they both flat!
If it goes direct to a solenoid, or an electrical looking "box" first, and then continues on to the first battery, it is most probably wired via an isolator, and the second battery may be in good condition and suitable for jump starting.
I would charge the first battery asap, If you have a good second battery then you can just replace the first battery with the second, If they are both start batteries, as it is better to have a reliable start battery if you have the choice, and replace or charge the faulty battery.

It sounds like you will need the advice of a qualified auto leci as it is not really good to give this type of advice here without knowing the type and actual conditions of each of the batteries and why one or maybe both are stuffed, or if you have a computer ignition system or equipment that can be harmed by careless jump starting!!

either both batteries are flat in which case NO or they are isolated by a solonoid which will not connect the 2nd batterie if the starter is DEAD FLAT if this is the case all you need is an override switch to activate the solonoide which brings the 2nd batterie into play (I have this systm in my camper)

Skinny,

Just reading between the lines here but I reckon you may have just had a flat main battery and quite possibly a second battery with charge??

When you were told that "if you were stuck that the other battery would start it" I'm assuming whoever said that meant with the aid of jumper leads, by using the "second" battery just like useing someone elses car?

The majority of twin battery set ups are seperate systems so as to avoide flattening your "starter" battery when using accesories etc from you second battery.

I once left home early one morning for a fishing trip with lights on and apon arrival at my destination the sun was now up and I didn't realise my lights were still on, after heading out in the boat all day I returned to the car only to find the rig would not turn over, I grabbed the jumper leads and connected the second battery (wich had run the engel allday keeping the froffies cold) to the starter/flat battery and away she whent!

I reckon thats what you could do!

Browny