New (to me) rig with potential electrical "issues" - Page 8

**daveb** · 10-23-2013, 09:08 PM

Oops forgot you went with 12v batteries. In that case you can connect the charger to either battery or even connect to the correct side of the separator and ground block if necessary.

As long as you don't have a large inverter you'll be OK with #4 copper. With my 2000w inverter 2/0 is ok or 4/0 is recommended especially if the run from the batteries is over 6 feet away. But check what the manufacture says.
Your wire size is based on your total load and how long that load is applied. Microwaves pull a lot and usually for a fairly long time. They usually require 1200w or larger inverter to run the smaller ovens.
W/O an inverter most SMB have smaller loads...pumps, lights, A/V equipment and the like doesn't pull too much and I would think 4 STR would be fine.

General recommendations:
Inverter Size < 3 ft.... 3ft - 6ft ......6ft.... < 10ft
400 Watts------- 8---------- 6--------- 4
750 Watts------- 6---------- 4--------- 2
1000 Watts------ 4---------- 2--------- 1/0
1500 Watts------ 2---------- 1--------- 3/0
2000 Watts------ 1/0------- 2/0------- 250
2500 Watts------ 1/0------- 3/0------- 350
3000 Watts------ 3/0------- 4/0------- 500
5000 Watts------ 3/0------- 4/0------- 500
6000 Watts------ 3/0------- 4/0------- 500

mikracer · 10-24-2013, 09:45 AM

No large inverter for me. To use the microwave, I will have to be plugged into shore power or generator. The primary draw items I have are the fridge, water pump, and interior lights. I don't have any A/V equipment installed but there is a small (350 watt) inverter that is mounted near the cig lighter that might get occasional use. I'm thinking the 4 gauge wire I put in will be enough, especially since the rig was set up and working with the smaller gauge wire before. It'll all get tested out this weekend when we take it on an overnighter at the beach.

Any input on the voltage output from the alternator? I did some googling and people were saying with a cold engine/alternator, it will put out more voltage, then regulate itself when it warms up. I might have to take it for a spin after work today to get it warmed up and see what the readout is.

**daveb** · 10-24-2013, 12:20 PM

Mine never goes above 14.7 and 99% of the time reads 14.1 +/- a fraction of a volt....13.8 through 14.4v.

Gel batteries are the ones that need a lower voltage but most AGM's charge as any other wet cell battery.

xcnick · 10-24-2013, 12:28 PM

Quote:

Originally Posted by daveb

Gel batteries are the ones that need a lower voltage but most AGM's charge as any other wet cell battery.

As I ask Jeeves, search the web this morning I am thinking the float charge is the main change. The lower setting of the Power Source was bad for my wet cell battery but perhaps it is perfect for an AGM.

**daveb** · 10-24-2013, 01:55 PM

I'm sure each manufacture has a specific guideline and there seems to be some different values out there. Bulk and absorpsion charging voltages are fairly close although bulk voltages can be lower. Heat is a big issue.

mikracer · 10-28-2013, 03:09 PM

Took the rig out this last weekend on its first trip. I kept an eye on the voltage from the innova monitor and once the engine/alternator warmed up to temp, it was charging the house batteries at around 14.8-9volts. Pretty much where it needs to be at. My two new batteries held up great overnight and should keep the fridge running for 2 days no problem. Thanks again everyone for your help with everything.