2018 VLX Battery Switch to ACR Combine Type vs 1, 1+2, 2

[MLA]

Id want my donor vehicle running. prior to connecting to the dead vehicle. As soon as you connect the cables, the good battery is going to start to equalize into the dead battery. although a slim chance, you run the risk of drawing down the good battery before starting its engine. 

If the COMBINE position on the dead boat was not enough to re-fire the engine, then theres a good chance you have 2 dead banks or a shorted main cranking battery.

So, id put the donor boat on the main cranking bank and put the dead boat's switch on whichever battery is NOT the main cranking. Gut says the other bank is your best bet to re-fire engine.  

[dalt1]

1 hour ago, MLA said:

Id want my donor vehicle running. prior to connecting to the dead vehicle. As soon as you connect the cables, the good battery is going to start to equalize into the dead battery. although a slim chance, you run the risk of drawing down the good battery before starting its engine. 

If the COMBINE position on the dead boat was not enough to re-fire the engine, then theres a good chance you have 2 dead banks or a shorted main cranking battery.

So, id put the donor boat on the main cranking bank and put the dead boat's switch on whichever battery is NOT the main cranking. Gut says the other bank is your best bet to re-fire engine.  

Mine was completely dead both batts due to alternator not charging. I was running combined as I usually do. Did not notice the voltage drop till too late. Was trying to get back to ramp. We hooked to a single batt on my boat My switch was still in both I don't know where his was and it fired right up but still only showing 9.7 volts on dash.

[justgary]

12 hours ago, dalt1 said:

Mine was completely dead both batts due to alternator not charging. I was running combined as I usually do. Did not notice the voltage drop till too late. Was trying to get back to ramp. We hooked to a single batt on my boat My switch was still in both I don't know where his was and it fired right up but still only showing 9.7 volts on dash.

If you have depleted both batteries and have no charging system, your goal is to get enough charge to make the run home.  In that case, I would choose the smaller of the two batteries on board and let the donor charge only that one.  Leave it connected with the donor running (at high idle if possible) for as long as you can stand before cranking the dead battery.  Resist the urge to combine batteries again before you repair the charging system.  Leave all unneeded accessories off on the way home, and don't kill the engine until you know you won't need to crank it again.