Go Back   Thor Forums > Thor Tech Forums > Modifications and Updates
Click Here to Login
Reply
 
Thread Tools Display Modes
 
Old 05-08-2019, 03:50 AM   #21
Senior Member
 
Brand: Still Looking
State: Texas
Posts: 3,861
THOR #2121
Quote:
Originally Posted by Beau388 View Post
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 is online now   Reply With Quote
Old 05-08-2019, 01:09 PM   #22
Senior Member
 
Brand: Still Looking
State: Texas
Posts: 3,861
THOR #2121
I didnít 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, itís 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 isnít as bad as in the example.

Iím honestly impressed with capability to provide 540 Amps at 42 Volts, but thatís 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 shouldnít 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. Iíve been a proponent of 48V systems for many years, and was glad to see Volta start the transition. Unfortunately, for most do-it-yourselvers, itís 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 donít have the same amount of voltage drop at high currents. Thereís a lot to consider
__________________

__________________
Chance is online now   Reply With Quote
Old 05-08-2019, 02:05 PM   #23
Senior Member
 
Brand: Thor Motor Coach
Model: Hurricane 31S
State: Texas
Posts: 1,313
THOR #6411
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.
__________________
Jim & Roy Davis
2016 Hurricane 31S
1961 Rampside in tow
Beau388 is offline   Reply With Quote
Old 05-08-2019, 02:29 PM   #24
Junior Member
 
Brand: Thor Motor Coach
Model: Vegas 25.2
State: North Carolina
Posts: 17
THOR #14969
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/
__________________
2016 Thor Vegas 25.2
2008 FJR1300
Front Sumo Springs
symchuk is offline   Reply With Quote
Old 05-11-2019, 06:35 PM   #25
Senior Member
 
State: Alaska
Posts: 236
THOR #8813
Quote:
Originally Posted by symchuk View Post
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.
__________________
carlgorski is offline   Reply With Quote
Old 05-11-2019, 07:51 PM   #26
Senior Member
 
Brand: Thor Motor Coach
Model: Hurricane 31S
State: Texas
Posts: 1,313
THOR #6411
Quote:
Originally Posted by carlgorski View Post
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 .
__________________
Jim & Roy Davis
2016 Hurricane 31S
1961 Rampside in tow
Beau388 is offline   Reply With Quote
Old 05-11-2019, 07:52 PM   #27
Junior Member
 
Brand: Thor Motor Coach
Model: ACE 27.2
State: California
Posts: 14
THOR #15058
Quote:
Originally Posted by symchuk View Post
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:
Donít 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. Iíll only use the inverter when off the grid and no gen running, so for me itís a great solution.
__________________
richguess1946 is offline   Reply With Quote
Old 05-12-2019, 05:18 PM   #28
Junior Member
 
Brand: Thor Motor Coach
Model: Quantrum RC25
State: California
Posts: 17
THOR #14016
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.
__________________

__________________
Junodtim is offline   Reply With Quote
Reply

Tags
inverter, vegas 25.2

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Featured Campgrounds

Reviews provided by

Disclaimer:

This website is not affiliated with or endorsed by Thor Industries or any of its affiliates. This is an independent, unofficial site.




All times are GMT. The time now is 11:55 PM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.0 PL2