Installing a AIMS 3000 Watt Inverter/Charger in a Vegas.

[Chance]

Originally Posted by Beau388

You are forgetting what happens when you ask a deep cycle to produce 600 amps or so. The reason they are deep cycle is because they have thick plates with very little surface area as compared to dual use or starting batteries. Ask a CG-2 deep cycle to produce more than 50 amps and the voltage will drop precipitously. In my golf cart with 8 - 6 volt CG-2 deep cycle, with fully charged batteries, max acceleration is the amperage draw is 540 amps @ 42.0 volts volts (3.0 hp -2.2 kw). That figures to 10.5 volts for a battery pair. That will cause a low voltage shutdown on most inverters.

Seriously? You think I forgot something?

Read your post again and see what you missed.

[Chance]

I didn’t want to type much at midnight for fear of being half asleep.

When comparing Apples and Oranges, we have to start over because conditions are very different. While 800 to 1,000 Amps may sound crazy, it’s at 12V nominal, not 48V.

Looking at eight typical 6V golf cart butteries with ratings in the 200~225 Amp-hr range, if wired in 4 parallel strings of 2 batteries in series each to make a 12V system, the current per battery isn’t as bad as in the example.

I’m honestly impressed with capability to provide 540 Amps at 42 Volts, but that’s 23,000 Watts, in the range of three times more power than should be needed to start an efficient A/C. With minor A/C modifications it could be much less than that.

Realistically, even at 800 Amps at 12V nominal, each battery string would only see 200 Amps, and only for a few seconds. Voltage shouldn’t drop as badly as your 540 Amps.

Anyway, once inverters get large enough to power a typical roof-top RV air conditioner, I would personally avoid a 12V system. I’ve been a proponent of 48V systems for many years, and was glad to see Volta start the transition. Unfortunately, for most do-it-yourselvers, it’s a little early still.

We also have to keep in mind that many advanced DIY types are going to lithium batteries to save weight and space, and those batteries don’t have the same amount of voltage drop at high currents. There’s a lot to consider

[Beau388]

Sorry I did not proof read my post, so my calculations are amiss. The golf cart (EZ-GO TXT) has all the batteries in series and the nominal voltage is 6.3 volts per battery 50.4 volts fully charged. The figures for the motor are 2.2 kw or so the current is 54.0 amps @ 42 volts or 2,268 watts. All this is measured by my HF clamp on ammeter and the golfcart's voltmeter so the readings are shall we say, suspect. My point (poorly made) was pulling more than 50 amps out of a 6 volt battery will result in a serious voltage drop; probably enough to have the inverter shutdown. These are only for the GC-2 battery size. Larger batteries obviously can supply more current successfully.

[symchuk]

I have been using "Welcome Boondockers" and some of these places do not offer shore power or allow generators to run. So, I am stuck with A/C on batteries. Now this has been very informational on how much power my 1300 Watt A/C could draw on startup and how much batteries will be needed. I think once I get up to 4 Lithium batteries, I will probably switch everything over to a 48V system. I am not sure I want to add solar to a 12V system. Anyone running a 48V solar system?

Has anyone installed a second alternator? When I go to a 48V system, I may a second alternator at the 48V level. I saw this company that has the kit for the E450.
https://www.nationsstarteralternator.com/

[carlgorski]

Originally Posted by symchuk

120V side:
It looks like at 120 Volts A/C, the 10 Gauge wire from the transfer switch to the inverter than from the inverter to the circuit panel should do the trick.

12V side:
This is where things get trickier. Since I am planning on installing lithium batteries right beside the inverter, I am estimating that I will need less than 4 feet of cable from the inverter to the batteries and back, which looks like 4 guage will work. I could use 2 guage if I wanted more insurance policy. It appears that the length of cable can play major factor.

I am referencing this link to determine which gauge of wire to use.
12 Volt Wiring: Wire Gauge to Amps | Offroaders.com

I am open to suggestions and feedback. Is there a favorite Lithium batter out there?

Many inverters suggest running 2 hots and 2 grounds. I had problems with mine until I did this.

[Beau388]

Originally Posted by carlgorski

Many inverters suggest running 2 hots and 2 grounds. I had problems with mine until I did this.

When you are starting with 12.2 volts nominal, then anything over about 1/2 ohm for the total cable run is detrimental. Any cable larger than a 2 gauge cable gets hard to handle, so it easier to run two cables rather than on large one. For instance, the area of two 2 gauge cables is equal to one 2/0 cable. Also the number of cores in the cable has a great effect (i.e. - 2 gauge single core is rated at 170 amps, a three core 95 amps and a 24 core at 57 amps). That is because the air spaces between the cores in a cable take up space that would be available in solid core cable of the same diameter .

[richguess1946]

Originally Posted by symchuk

I was looking at different options for an inverter and ended up settling on a 3000 Watt Inverter. I have a 25.2 vegas and there is no room behind the fuse panel for the 1200 watt that I saw lots of videos for. The space beside it has the furnace. I do have a sofa bed in mine with lots of room beside the water tank. I even have room for 2-4 lithium batteries in the future. I found the transfer switch under the stove. I was planning to go from the transfer switch, under the floor than back up under the sofa. Does anyone have any advice for drilling through the floor and how to seal the holes?

I just put a 1500 w in my 27.2 ACE.

Couple of things:
Don’t put the inverter in the same compartment as the batteries.
Keep it close to the batteries, those are big wires.

I installed mine in the compartment next to the batteries, ran the wires out thru a hole I drilled. Used the foam stuff to fill the holes. Mine had a remote on/off switch. I ran that up to a place by my thermostat.

Next, I ran the 120v side into the area where the 120v distribution panel is. I found which plugs I wanted to have inverter power to, and cut those wires after they exited the box, on their run to the plugs. Then I installed an A/B switch for shore/off/inverter. The ACE is probably different, but same concept. This way no getting into transfer switches, etc. I’ll only use the inverter when off the grid and no gen running, so for me it’s a great solution.

[Junodtim]

I installed a 750 watt inverter with 4PDT on/off/on switch to circuit for TVs and oscillating fans. Two poles are swap hot and natural wires, the third pole I used to to turn inverter on. I mounted the inverter next to power distribution panel and used 12 inches of no 6 wire to the slave side of the 12 volt relay. I left the inverter on all night with one TV on and still had enough juice to start the generator in the morning. When in need of air conditioning, I use the generator.

[dwinslow]

Originally Posted by Mo_Mike

Can't believe I didn't take a picture (I normally take pictures upon pictures)

On ours, I pulled out the WFCO converter. The wires feeding the back of the CONVERTER were cable tied to a wooden cross support. We cut the cable tie holding the cables, which gave us more flexibility (and room)

We built a wooden "H", screwed to the cross member referenced above and a another cross support toward the back of the compartment.( on the vertical legs of the "H")

The inverter sits on top of the "H", so there is plenty of air space on all sides.

On ours the USE/STORE relay is attached to the front of the same cross member referenced above. We attached a 4guage wire to the RELAY then to the INVERTER ( with a 150 amp breaker inline)

Wasn't the most "fun" place to work, but have been in tighter places.

Question, did you upgrade the 6 gauge wire between the batteries and the use/store relay also? I am Trying to decide on how best to wire the dc side.

[symchuk]

I used 1/0 guage wire directly from the batteries to my inverter with an inline 200amp fuse.

[Bob Denman]

How is everything working so far?

[symchuk]

For the most part, everything works well. I am in the process of researching lithium batteries and adding a second alternator just to charge the lithium batteries. If I go that route, I may upgrade my battery system to 48V.

[galOnTheGo]

we put our 3000w renogy beside the water tank, under bed. fits nice, easy to connect, room to breath. only real down side was it needs a 15ft cable to connect to battery. it was an easy run, but longer than I would like. I am looking into moving the battery someplace closer, under bed somewhere. comments welcome.

[symchuk]

I just purchased a split panel for my motorhome. I was having issues with the a/c not playing well with the inverter even when I was on shore power. The split panel allows me to choose which circuits are powered by the inverter and which are shore power only. The new panel is designed to replace my factory installed panel.

[ducksface]

Originally Posted by symchuk

I just purchased a split panel for my motorhome. I was having issues with the a/c not playing well with the inverter even when I was on shore power. The split panel allows me to choose which circuits are powered by the inverter and which are shore power only. The new panel is designed to replace my factory installed panel.

My ac also messes with the inverter. Do you have a picture or link on that panel?

[symchuk]

Here is a link to the panel.

https://www.boatandrvaccessories.com...ries-split-bus

[ducksface]

Originally Posted by symchuk

Here is a link to the panel.

https://www.boatandrvaccessories.com...ries-split-bus

Thanks.
I'll do it when I add the battery bank.