What gauge wire needed to parallel 12v deep cycles

mrad wrote:
There is no furnace fan to run. The inverter will only be running when the generator is off and charging will only take place when the generator is off.

Part of this is to see if there is a difference in the bite when generator is not running. Guides on the lake debate if the generators hurt the fishing. Some think the vibration may actually attracts fish while others are convinced it spooks them. It's also nice to sit in the house in silence as the sun sets.

I was going to order these cables

https://www.amazon.com/Gauge-Copper-Battery-Inverter-Cables/dp/B00SFXVMYW/ref=sr_1_sc_2?ie=UTF8&qid=1543425683&sr=8-2-spell&keywords=battery%2Bparralel%2Bcables&th=1

A friend has 4AWG if that would be sufficient.

Whats considered a good volt meter? On Amazon they range forn $12 to $137.

Again, thanks to all for the info. Great to have a resource like this site to be able to get some great info.

I missed how you will run the charger when the generator is not running!

Any old digital multimeter will do for the DC voltages you want (15-11)--costs maybe $10 at various stores.

Being more of a mad scientist than a fisherman, I would hoist the gen above the ice on a block and tackle from the shack's rafters and see how many fish per hour you catch with it on and then off the ice. Do that for several days to get enough data for proving the theory vs fact per usual lab testing requirements. :)