adding batteries

[MACFLAIR]

We have a 27 ft fleetwood flair, our first. It only has room for 1 coach .and 1starter batt.I have a compartment that i reinforced that will hold two more batts. The batts are 12 volt . I know the stats on 6 volts, but for the limited camping we will do at this time, i am sticking with 12 volts. The question i have is,the compartment is, when i route the wires,about 9 ft away from the front batt that i will be connecting in parallel to. Without an inverter, which i dont see up grading to for quite a long time,what size wire can i use to connect front and rear batts . I have looked at other Elec sites , smart gauge, and others. i get some of it but the rest is over my head. We do not have a generator.Thanks for any help. John and Nancy

[RV Wizard]

Use a wire gauge of the next large size that is connected to the original battery. Be sure to route and protect the conductors with a circuit breaker equal to the amperage rating of the wire size.

[paz]

Also, make sure the compartment you're planning to put the batteries into is well ventilated and does not contain any electrical equipment. All lead-acid batteries (even AGM) give off hydrogen gas, which is highly flammable. The batteries must be vented and must not be located near an ignition source.

[gasser 38]

0 gauge is the charger capable of handiling the additional batteries. Does the engine also charge these you may have a problem with the alternator as well